technical information - timber germany

1 Technical Information - Issued 12/2009

TECHNICAL INFORMATIONKVH®, DuObALKEN®, TRIObALKEN®

KVH®

2 Technical Information - Issued 12/2009 Technical Information - Issued 12/2009 3

Contents

1 A high-precision material 3

2 Production and technical characteristics 5

3 Requirements and fields of application 6

4 Product range and preferred cross-sections 8

5 Dimensioning

5.1 Dimensioning principles in accordance with DIN 1052 9

5.2 Example calculations for a timber beam ceiling 12

6 Dimensioning reference tables 16

6.1 Cross-sectional values and dimensioning values 17

6.2 Ceiling beam cross-sections 18

6.3 Post cross-sections 26

6.4 Rafter cross-sections 27

7 Context provided by current standards 30

8 Tenders and principles of standards 32

9 Quality assurance and marking 34

10 Advantages of KVH®, Duobalken® and Triobalken® 36

1 A high-precision material

Building with wood has a long tradition. Over the

thousands of years of man’s development, build-

ings constructed of wood have repeatedly proved

their value throughout the centuries, not only

for providing comfortable shelter but for their

durability as well.

Better than required by the standards

Technical directives, regulations relating to build-

ing physics, changes in attitudes to the use of

energy and more exacting quality standards for

housing all mean that the requirements to be

met by building materials are high. With the diver-

sification of the timber construction industry over

recent decades into timber frame building and

prefabricated timber panel construction, demand

for high-quality construction timber has grown

enormously. Modern timber construction requires

dimensionally stable, kiln-dried structural timber

with precise dimensions. As the production tech-

nology in carpenter’s shops has changed, with

CNC-controlled trimming lines now commonplace,

so materials with clearly defined specifications

have become a precondition for smooth produc-

tion processes. This is also reflected in the current

stipulations in the relevant standards.

The requirements set out in the agreement on

KVH® structural timber are actually far more

stringent than those contained in the related

standards, as explained below.

Technological advantages

The development of KVH® structural timber

and Duobalken® and Triobalken® beams means

that customers are now able to count on high-

precision materials which are available ex stock

in numerous dimensions and lengths in the form

of kiln-dried, dimensionally stable and planed or

exactly sized products.

KVH®, Duobalken® and Triobalken® are protected

brand names. Quality controls during the produc-

tion of KVH® structural timber are performed

according to the strict rules of the Überwachungs-

gemeinschaft KVH®, which also monitors that the

rules are properly followed. The quality control

stipulations of the monitoring group are set out

in an agreement made with the Federation of

German Master Carpenters (Bund Deutscher Zim-

mermeister [BDZ]). Duobalken® and Triobalken®

laminated beams must meet the requirements

for the general technical approval of the German

building authorities as assessed by the Deutsche

Institut für Bautechnik (DIBt).

Publisher:Überwachungsgemeinschaft KVH Konstruktionsvollholz e.V. Elfriede-Stremmel-Str. 69 42369 Wuppertal - GermanyTel. ++49 (0)700 - KVH DUO TRIO or ++49 (0)700 - 58 43 866 87 Fax ++49 (0)0202 – 978 35 [email protected] und www.kvh.eu

Technical information:bauart Konstruktions GmbH + Co. KG Spessartstraße 13 36341 Lauterbach - Germany www.bauart-konstruktion.de

Editorial office:Dr. - Ing. Tobias Wiegand

Layout:radermacher schmitz pr53639 Königswinter- Germany

Photo credits

Cover, Page 7, 10, 21, 34-35:

Überwachungsgemeinschaft Konstruktionsvollholz e.V.

: Residential, office and ex-hibition building Landma-schinen-fachbetrieb Rufer,69198 Schriesheim/Karla Rufer, Susanne Jacob-Freitag, 76185 Karlsruhe

Page 4 : Residential building Schnei-der: Bauer Holzbau GmbH, 74589 Satteldorf-Gröningen/Björn Rudnik Hausfotografie

Page 11,31 Libeskind Villa prototype; Empfangsgebäude der Rheinzink GmbH & Co. KG: Josef Pieper GmbH, Rheinzink, 45711 Datteln/ proportion GmbH, 10245 Berlin

Page 12: Community center Diedorf: müllerblaustein, BauWerk-Partner, 89134 Blaustein

Page 15: House Thomas: Heinz-Holzbauplanung & Zimmerei, 57299 Burbach/Hartwig Heinz

Page 27 top: Rettenmeier Holzindustrie Hirschberg GmbH & Co. KG ,07927 Hirschberg

bottom: Office building, Company E+K Verwaltungs GmbH & Ko.KG: Bauer Holzbau GmbH, 74589 Satteldorf-Gröningen

Page 32: Residential building, Stimp-fach: Bauer Holzbau GmbH, 74589 Satteldorf-Gröningen/Björn Rudnik Hausfotografie

Issued 12/2009

KVH® structural timber

Solid timber for exposed and non-

exposed applications which is visually

graded or machine graded and is kiln-

dried, planed or exactly sized1) and co-

mes with defined dimensional stability.

As a general rule KVH® is finger-jointed.

It is normally supplied in lengths of 13

m, but longer lengths are available on

request. 1) Exactly sized: Planed to size after

drying, without any guarantee of

smoothly planed out surfaces.

Duobalken® und Triobalken®

Laminated beams in accordance

with DIN 1052 which have the same

properties as KVH® and are made of

either two or three individual lengths

of wood with identical cross-sections

which are glued together. The indivi-

dual lengths of wood are also finger-

jointed like KVH®. They are normally

supplied in lengths of 13 m, but longer

lengths are available on request.


Technical characteristics KVH® Duobalken®/Triobalken®

Wood species Spruce. On request: Fir, pine, larch, Douglas fir

Grading class compliant with DIN 4074 S 10 (S 13 on request)

Strength classes and characteristics

*Deviation from DIN 1052:2008-12

C24 / C30 in accordance with DIN 1052:2008-12

E0,mean

= 11.000 N/mm² E0,mean

= 11.600 N/mm²

Moisture content um 15 % ± 3 % ≤ 15%

Swelling and shrinkage ratio 0.24% per 1% change of wood moisture content

Reaction to fire class in accordance with DIN EN 13501-1 and/or DIN 4102

D-s2, d0 or B2 (normal flammability)

Weight in accordance with DIN 1055-1 5 kN/m³

Thermal conductivity 0.13 W / (mK)

Water vapor diffusion resistance factor µ 40

2 Production and technical characteristics

In the production of KVH®, Duobalken® and Trio-

balken®, only softwood of the highest quality is

used for primary conversion to rough beams on

state-of-the-art chipper and circular saw lines. The

waste wood from the process, such as bark, chop-

ped wood and chips, is completely used up in the

generation of energy and in the production of pa-

per or derived timber products. After drying in fully

automated, computer-controlled kilns, the timber

is strength graded. Growth non-conformities which

could reduce the strength of the product are cut

out of the beams and the ends are then re-joined

with finger-joints. This is an effective method for

the resource-saving utilization of the wood which

also results in optimized wood characteristics.

After the finger-jointing (subject to length this

can be dispensed with on request) the pieces

of timber are cross cut to length and planed or

leveled to an exact size. For Duobalken® and Trio-

balken® beams this is followed by the gluing to-

gether of the individual laminations and further

planing. The products are cured and stored in air

conditioned storage buildings to ensure that the

beams are dry and dimensionally stable before

they are delivered. Every stage of production is

subject to permanent quality controls (internal

and external controls and inspections). The re-

sults of the controls and inspections are recorded

and evaluated in order to ensure that a consis-

tently high quality is guaranteed at all times.

Sustainability

Wood has the advantage over other construction

materials in ecological terms. In addition to its

unique selling point of being the only renewable

structural construction material to be available

in large quantities, the fact that it is also associa-

ted with short transportation distances, is easy

to work and is produced with no waste are just

some of the reasons why the production of timber

building components requires less energy input

than building components made of other materials.

Precision prefabrication and energy-efficient

construction

The high level of dimensional stability offered by

KVH®, Duobalken® and Triobalken® is an important

prerequisite for efficient mechanical woodworking

in firms specializing in timber construction. With-

out these types of timber products it would not be

possible to use cost-saving CNC machines and

achieve a high degree of prefabrication.

Given the high standards that modern buildings

have to meet in terms of energy requirements,

the shells of buildings have to be permanently air-

tight. The building components must be finished

to an exact fit and the usual moisture-related

changes in the shape of the wood must not com-

promise the airtightness. High-tech timber prod-

ucts such as KVH®, Duobalken® and Triobalken®

make it possible to achieve airtight timber

buildings which are therefore energy-efficient and

have a high standard of heat insulation.

Healthy homes

The home stands for a feeling of well-being. KVH®,

Duobalken® and Triobalken® not only create a

sense of comfort and well-being in the home,

they also give architects considerable freedom of

design. German builders of prefabricated houses

and numerous firms specializing in timber con-

struction make extensive use of KVH®, Duobalken®

and Triobalken® in order to construct buildings

which are both spacious and cost-effective.

Table 2.1 - Elastomechanical and building physics characteristics


Table 3.1 - Requirements to be met by KVH® structural timber in accordance with the inspection regulations and the agreement

between the Bund Deutscher Zimmermeister (BDZ) and Überwachungsgemeinschaft Konstruktionsvollholz e.V.

Table 3.2 - Requirements to be met by Duobalken® and Triobalken® beams in accordance with the

general technical approval of the German building authorities as assessed by the Deutsche

Institut für Bautechnik (Z-9.1-440 dated 30/01/2009).

Fields of application for KVH® structural timber

Service Class (SC) 1 to 2 in accordance with DIN 1052 (see Table 3.3). Use in outside areas (SC 3) must be

checked in each individual case and is only possible if resistant species of wood are used (Larch/Doug-

las fir, sapwood-free), without finger-jointing. Preservative treatment is not required for Use Class GK 0

according to DIN 68800 ("Protection of wood"). For GK 1 to 3 the need for preservative treatment can be

avoided by selecting species of sufficient natural durability, Where preservative treatment is required, in

particular for GK3, oil type preservative according to a technical approval should be used.

Fields of application for Duobalken® and Triobalken® beams

Service Class 1 and 2 in accordance with DIN 1052 (see Table 3.3). Preservative treatment is not required

for Use Class 1 regardless of the species of wood (danger of insect attack). Resistant species of wood

(larch/Douglas fir, sapwood-free) can be used for GK 2 in accordance with DIN 68800. Alternatively an ap-

proved oil type preservative can be applied.

Table 3.3 - Use classes

Grading criterion Requirements to be met by KVH® structural timber Remarks

Exposed areas (KVH®-Si) Non-exposed areas (KVH®-Si)

Grading class compliant with DIN 4074-1

Min. S10TS; C24 in accordance with DIN 1052

The decisive strength and stiffness properties are given in DIN 1052.

Moisture content 15% ± 3% The specified moisture content is a precondition for dispensing for the most part with preservative treatment and can also be the precondition for finger joint assembly.

Type of cutting Split-heart; free-of-heart on request.

Split-heart Split-heart: Given that the pith does not always automatically run through the middle of the log, split-heart is defined as follows: For a log with an ideal growth form, the pith would be cut through in two-strand cutting.

Free-of-heart: Heart plank with d ≥ 40 mm is removedWane Not permitted Measured at an angle

≤ 10% of the smaller cross-section side

Dimensional stability of the cross-section

DIN EN 336 Dimensional stability class 2: w ≤ 100 mm: ± 1 mm w > 100 mm: ± 1.5 mm

The dimensional stability for the longitudinal dimensions must be agreed between the customer and supplier.

Knot condition Loose knots and dead knots not permitted. Occa-sional faulty knots or parts of knots up to max. 20 mm in diameter are permitted

DIN 4074-1 Grading class S10

Replacement with natural wood dowels is permitted. Maximum of 2 adja-cent to each other permitted for Si.

Knot diameter ratio S 10: A ≤ 2/5 S 13: A ≤ 1/5 not exceeding 70 mm

Knot diameter ratio A is determined in accordance with DIN 4074-1. The following applies for mechanical grading: • Knot sizes are not taken into consideration for KVH®-NSi • A ≤ 2/5 applies for KVH® -Si

Ingrown bark Not permitted DIN 4074-1

Cracks, radial cracks caused by shrinking (shrinkage shakes)

Width of the crack w must be ≤ 3% of the respective cross-section width

DIN 4074-1 For Si the requirements are higher than those applicable to grading class S10 in accordance with DIN 4074-1.

Pitch pockets Width w ≤ 5 mm Additional criterion

Discoloration Not permitted DIN 4074-1 For Si the requirements are higher than those applicable to grading class S10 in accordance with DIN 4074-1

Insect attack Not permitted DIN 4074-1 For Si the requirements are higher than those applicable to grading class S10 in accordance with DIN 4074-1

Twisting - - The permissible extent of twisting is not specified in further detail because no unacceptable twisting is to be expected if all the other criteria are complied with

Longitudinal warping ≤ 8 mm/2 m for split-heart cutting ≤ 4 mm/2 m for heart-free cutting

≤ 8 mm/2 m for split-heart cutting

In comparison: In accordance with DIN 4074-1 S10 and S13: ≤ 8 mm/2 m

Finishing of the ends Trimmed perpendicular

Surface quality Planed and chamfered Leveled and chamfered

Finger-jointing DIN EN 385

Grading criterion Requirements to be met by Duobalken® and Triobalken® beams

Remarks

Exposed areas Non-exposed areas

Technical standard General technical approval of the German building authorities No. Z 9.1-440

Modulus of elasticity II to fiber

E0,mean

= 11.600 N/mm2 Higher value compared to solid timber C24 in accordance with DIN 1052.

Grading class compliant with DIN 4074-1

Min. S10TS; C24 in accordance with DIN 1052

The decisive strength and stiffness proper-ties are given in DIN 1052.

Moisture content um Max. 15% Precondition for gluing

Dimensional stability of the cross-section

DIN EN 336, Dimensional stability class 2 w ≤ 100 mm ± 1 mm w > 100 mm ± 1.5

mm

The dimensional stability for the longitudinal dimensions must be agreed between the customer and supplier.

Twisting ≤ 4 mm/2 m In comparison: DIN 4074-1: S 10: ≤ 8 mm/2 m

Longitudinal warping ≤ 4 mm/2 m In comparison: DIN 4074-1: S 10: ≤ 8 mm/2 m

Surface quality Planed and cham-fered

Leveled and cham-fered

The right-hand sides (sides adjacent to the heart) must face outwards

Finishing of the ends Trimmed perpendicular

Finger-jointing DIN EN 385

Service classes in accor-dance with DIN 1052

Use class in accordance with DIN 68800

Example of normal application

Use of KVH®, Duobalken®/Trio-balken® beams

SC 1 – Dry areas um ≤

12% (5 to 15%)GK 0, GK 1 where accessible

to insectsBuilding components enclo-sed on all sides and heated

KVH®, Duobalken®, Triobalken®

SC 2 – Areas susceptible to high humidity u

m ≤

20% (10 to 20%)

GK 2 where temporary humi-dity is possible

Protected building compon-ents in a carport structure

KVH®, Duobalken®, Triobalken® beams made of larch/Douglas

fir heartwood

SC 3 – Outside areas um

> 20% (12 to 24%)GK 3 for outside areas expo-

sed to the weatherUnprotected building com-

ponents, balcony structures1)

KVH® made of larch/Douglas fir heartwood without finger-

jointing*

3 Requirements and fields of application

* An additional requirement for preserva-

tive treatment for GK 3 must be decided in

each individual case

Spruce

Larch

Douglas fir

PineFir


Dimensioning in accordance with DIN 1052:2008-12

- Design of timber structures - General rules and

rules for buildings

DIN 1052, which was first issued in 1988 and was

comprised of parts 1 to 3 along with Amend-

ment A1 from 1996, was replaced in 2004 by a

completely revised version of the standard with

a new safety concept. The new one-part standard

was added to the German Model List of Acknowl-

edged Technical Rules for Works (Musterliste der

Technischen Baubestimmungen) and was also

later added to the technical rules for works in-

corporated in the building regulations of the Ger-

man federal states. Once the application of DIN

1052:2004-08 became mandatory, the European

dimensioning standard ENV 1995-1-1 (Euro Code

5) was withdrawn at national level.

Since then an updated version of the standard

has been introduced - DIN 1052:2008-12. This ver-

sion includes amendments and additions which

were found to be necessary after the introductory

phase of DIN 1052:2004-08. It has been incorpo-

rated in the building regulations and reflects the

state-of-the-art in technology.

4 Product range and preferred cross-sections

Verification: Ed ≤ R

d

Dimensioning value for strain: Ed =

G · G

k + g

Q · Q

k

Dimensioning value for stress resistance: R

d =

kmod · R k

γM

1Dimensioning values indicated by

index d (design)

2 Characteristic values indicated by index k

KVH®, Duobalken® and Triobalken® beams made

of the wood species spruce are available for im-

mediate delivery from stock in a wide range of

preferred cross-sections. The wood species pine

and fir and the more moisture-resistant species

larch and Douglas fir are available on request.

Cost savings with preferred cross-sections

Preferred cross-sections in the construction di-

mensions typically used in timber construction

enable major cost savings to be made. For firms

specializing in timber construction the stocks of

timber held by timber wholesalers save them the

need to maintain extensive stocks themselves,

giving them planning freedom without tying

down operating capital. Industrial production sys-

tems enable manufacturers to produce at low cost.

Timber also supplied cut to special dimensions

as listed

The organization of production is so flexible that

it is also possible to supply lengths cut to special

building-specific dimensions "as listed". This

means that dried and dimensionally stable timber

can also be supplied where job order planning is

the preferred option.

Dimensions

The maximum available cross-sectional dimen-

sions of KVH® structural timber are limited by

the kiln-drying and minimum split-heart cut-

ting requirements. With maximum dimensions

of approx. 14/26 cm, KVH® structural timber is

capable of meeting most normal requirements,

e.g. for ceiling beam cross-sections. For larger

cross-sections or high requirements in terms of

appearance, Duobalken® and Triobalken® beams

are available, the cross-sectional dimensions of

which are subject to the limits set by the approval

by the German building authorities:

Duobalken® w/h ≤ 16/28 cm (2 x 8/28 cm)

Triobalken® w/h ≤ 24/28 cm (3 x 8/28 cm)

w/h ≤ 10/36 cm (3 x 10/12 cm)

5 Dimensioning

5.1 Dimensioning principles in accordance with DIN 1052

The new safety concept

Following the principles of European standards,

the latest version of DIN 1052 is no longer based

on a dimensioning method revolving around a

global safety factor within "permissible stresses".

For timber construction, as is the case with most

other construction materials, a semi-probabilistic

safety concept with partial safety factors is used

instead. The new standard also continues the

policy of differentiating between the verifica-

tions for load-bearing safety and serviceability

(deflection, vibration). What has to be checked in

relation to the verification of load-bearing capac-

ity is that the dimensioning values1 for the strain

(Ed) do not in any dimensioning situation exceed

the dimensioning values for stress resistance

(building component resistance Rd). The dimen-

sioning values are determined by multiplying

the characteristic2 action from permanent and

variable loads (Gk or Q

k) by the partial safety fac-

tors G or

Q. Similarly, the characteristic building

component resistance Rk is reduced by a material

partial safety factor M

.

Height (mm) 100 120 140 160 180 200 220 240

Width (mm)

60 n n n n n n n n

80 n n n n n n n n

100 n n n n n n n n

120 n n n n n n

140 n n n n n n

160 n n n n

180 n n n n

200 n n n

240 n

n = NSi = Si

Table 4.1 - Preferred cross-sections for KVH® structural timber

Height (mm) 100 120 140 160 180 200 220 240

Width (mm)

60 n n n n n n n n

80 n n n n n n n n

100 n n n n n n n n

120 n n n n n n n

140 n n n n n n

Table 4.2 - Preferred cross-sections for

Duobalken® and Triobalken® beams


In relation to the verifications of load-bearing

capacity, factor kmod

takes account of the particu-

lar material properties of the wood in depend-

ency on predominant climatic conditions and the

load duration. The climatic conditions are defined

within the framework of the service classes; see

the table on page 7. The modification factors kmod

are set out in DIN 1052, Table F.1. Checks on service-

ability must take into account the deformation

factors kdef

contained in Table F.2 in DIN 1052,

which take account of the variations in creep

behavior in wood and derived timber products.

Characteristic strength and rigidity properties

Given that the dimensioning concept in the cur-

rent DIN 1052 is not based on global safety factors,

future calculations will no longer be based on

permissible stresses. The grading classes for sawn

structural timber in accordance with DIN 4074-1

are allocated to strength classes in DIN 1052, the

numerical value of which, i.e. 5% quantiles deter-

mined by tests, gives the characteristic bending

strength; see the table. The characteristic strength

and stiffness properties for wood and derived tim-

ber products are contained in Annex F to DIN 1052.

Other changes contained in DIN 1052:2008-12

compared to DIN 1052:1988 - 04/1996-10

In addition to a fundamentally changed dimen-

sioning concept, a whole range of new findings

from research and development has also been

incorporated in the updated version of DIN 1052.

For example, the available options for providing

verifications for timber connections have been

considerably extended. The positive effect of a

higher density can be taken into account in rela-

tion to the load-bearing capacity of fasteners and

the spacing of fasteners. Moreover, the standard

also contains a practical dimensioning method for

wall panels, ceiling sections and wall diaphragm.

1) Specification of permissible bending

stress in accordance with the now obsolete

DIN 1052:1988/1996, where the permissible

B = 10 N/mm².

2) Specification of characteristic flexu-

ral strength in accordance with DIN

1052:2008-12, where fm,k

= 24 N/mm2, which,

in contrast to the permissible B, does not

contain a global safety factor.

Wood species (softwood) Grading class in accordance with

DIN 4074-1

Strength class in accordance

with DIN 1052

Spruce, fir, pine, larch, douglas fir

S 7 TS

S 10 TS1)

S 13 TS

C 16 TS

C 24 TS2)

C 30 TS

Table 5.1 - Correspondence between grading classes and the strength classes defined in DIN 1052:2008-12

Duobalken® Triobalken®KVH®


Table 5.2 - Load combinations for verifications of load-bearing capacity

No. Combination Combination rule Dimensioning value Load duration class kmod

LK 1 g 1.35 · gk

qd = 2.36 kN/m² Long 0.60

LK 2 g + p 1.35 · gk + 1.5 · q

kq

d = 6.56 kN/m² Medium 0.80

LK 2 is clearly decisive in this case, and this is used for further consideration.

3. Characteristic strength and rigidity properties C 24

Characteristic bending stress fm,k

= 24.0 N/mm²

Characteristic shearing stress fv,k

= 2.0 N/mm²

Modulus of elasticity E0,mean

= 11.000 N/mm²

Dimensioning values for stress resistance

Modification factor for solid timber kmod

= 0.80

Partial safety factor for wood M = 1.3

Dimensioning value for flexural strength fm,d

= 0.8 · 24.0/ 1.3 fm,d

= 14.8 N/mm²

Dimensioning value for shear strength fv,d

= 0.8 · 2.0 / 1.3 fv,d

= 1.23 N/mm²

4. Stresses - Internal forces and moments and reactions at support

Internal forces and moments per beam (e = 62.5 cm)

Reference moment for LK 2:

Md = q

d · l² / 8 = 6.56 · 4.50² / 8 · 0.625 M

d = 10.38 kNm

Reference lateral force for LK 2:

Vd = q

d · l / 2 = 6.56 · 4.50 / 2 · 0.625 V

d = 9.23 kN

Characteristic reactions at support for the decisive LK 2:

End support A and B: Ag,k

= Bg,k

= 1.75 · 4.50 / 2 Ag,k

= 3.94 kN/m

Aq,k

= Bq,k

= 2.80 · 4.50 / 2 Aq,k

= 6.30 kN/m

DIN 1052, Table F.5

DIN 1052, Table F.1

(SC 1, load duration class: medium)

Rd =

kmod · R k

γM

l = 4.50 m

Results from the following dimen-

sioning reference tables are shown in

boxes with a green background

Strength class C24 corresponds to grading

class S 10 in accordance with DIN 4074-1;

see the table on page 8

qk,N

= load for habitable rooms and office

floorspace in accordance with DIN1055-3,

plus addition for partition walls of 0,8 kN/m²

qk,N

gk

l

5.2 Example calculations for a timber beam ceiling

1. System, building component dimensions

Timber beam ceiling in the form of a

simply supported beam

Spacing between beams: e = 62.5 cm

Material: KVH®structural timber, C 24

2. Characteristic action

Permanent (dead loads) gk = 1.75 kN/m²

Variable (live load including lightweight partition walls) qk,N

= 2.80 kN/m²

Results from dimensioning reference table 6.2.2 – Ceiling beams, e = 62.5 cm, C24

For: l = 4.50 m

gk = 1.75 kN/m²

Result A (without vibration

verification)

Result B (with simplified vibration

verification)

qk,N

= 2.80 kN/m² KVH® C24: 8/24 cm KVH® C24: 12/24 cm

Alternative::

Duobalken®,Triobalken® C24: 14/22 cm

Two dimensioning situations have to be

examined: permanent and variable action

Load duration class in accordance with DIN

1052, Table 4


5. Preliminary estimate

Required section modulus:

Wy,req

= Md / f

m,d = 10.38 · 10³/ 14.8 W

y,req = 701 cm³

Results from dimensioning reference table 6.1 (Cross-sec-

tional values):

For Md = 10.38 kNm Required w/h = 8/24 cm

6. Verifications for the limit of load-bearing capacity state

Dimensioning value for bending stress:

m,y,d

= Md / W

y = 10.38 / 768 · 10³

m,y,d

= 13.5 N/mm²

Verification: σm,y,d

= 13.5 = 0.91 < 1

ƒm,d 14.8

Dimensioning value for shearing stress:

d = 1.5 · V

d / A = 1.5 · 9.23 / 192

d = 0.72 N/mm²

Verification: τd

= 0.72 = 0.59 < 1

ƒv,d 1.23

7. Verifications for the limit of serviceability state

According to DIN 1052, Section 9.2, the following three cases have to be examined each one is only shown

for variable action:

a) Limitation of deflection as a result of variable loads (initial deflection without creep influences):

wQ,inst

= wQ,1,inst

+ 0,2

· wQ,2,inst

≤ l/300

b) Limitation of final deflection with creep influences as a result of all loads without consideration of

initial deflection:

wfin

– wG,inst

= wG,inst

(1 + kdef

) + wQ,1,inst

(1 + ψ2,1

· kdef

) – wG,inst

≤ l/200

c) Limitation of deflection in the quasi-permanent dimensioning situation for guaranteeing general us-

ability and appearance:

wfin

– w0 = w

G,inst (1 + k

def) + w

Q,1,inst · ψ

2,1 (1 + k

def) – w

0 ≤ l/200

Calculation of deflection

E0,mean

· Iy = 1.100 · 9.216 = 10.14 · 106 kNcm²

wQ,inst =

5 · g

k · l 4

= 5 ·

(1.75 · 0.625) 10 -2 · 450

4

= 0.58 cm 384 E

0,mean · I 384 10.14 ·10 6

wG,fin

= wG,inst

(1 + kdef

) = 0.58 · (1 + 0.6) = 0.928 cm

wQ,inst =

5 · g

k ,N · l 4

= 5 ·

(2.80 · 0.625) 10 -2 · 450

4

= 0.92 cm 384 E

0,mean · I 384 10.14 ·10 6

Proof of deflection

Case a) wQ,inst

= 0.92 cm = l/489 < l/300

Case b) wfin

– wG,inst

= 0.58 (1 + 0.6) + 0.92 (1 + 0.3 · 0.6) – 0.58

= 1.43 cm = l/313 < l/200

Case c) wfin

– w0 = 0.58 (1 + 0.6) + 0.92 · 0.3 (1 + 0.6) - 0

= 1.37 cm = l/329 < l/200

Simplified vibration verification

(Limitation of deflection as a result of quasi-permanent action to w = 6 mm in accordance with DIN 1052,

Section 9.3):

w = wG,inst

+ ψ2 · w

Q,inst = 0.58 + 0.3 · 0.92 = 0.86 cm

w = 8.6 mm > 6 mm (verification requirement not met)

Option 1:

Increase the moment of inertia / the beam width by 8.6/6 • 100 = 43%.

Comparison with the results from dimensioning reference table 6.2.2

For dimensioning criterion B: Required w/h = 12/24 cm

Option 2:

It is recommended that exact vibration verifications be calculated, which should provide more cost-effec-

tive results. Suitable verification methods can be found, for example, in "Erläuterungen zu DIN 1052:2004-

08" [1] ("Commentary on DIN 1052:2004-08").

Cross-sectional values for

w/h = 8/24 cm

A = 192 cm2

Wy = 768 cm²

Iy = 9.216 cm³

See also [1]

in accordance with DIN 1055-

100 for live loads falling under Category A

or B (Habitable rooms, office floorspace)

Here: ψ2,1

= 0.3

Deformation factor kdef

for permanent

action in accordance with DIN 1052, Table

F.2 for solid timber: kdef

= 0.6

Deflection stiffness for cross-section

w/h = 8/24 cm

The natural frequency in the case of de-

flection criterion w ≤ 6 mm exceeds 8 Hz;

this means that serviceability has been

verified as a result.

References:

[1] Blas, H.J.; Ehlbeck, J.; Kreuzinger, H.;

Steck, G.: Erläuterungen zu DIN 1052:2004-

08, Publisher: Deutsche Gesellschaft für

Holzforschung, Munich, 2nd edition 2004.


The dimensioning reference tables are intended

to provide an aid for day-to-day work. With the

help of the tables it is possible to make quick

preliminary estimates for the common situations

associated with residential and administrative

buildings – however, they cannot provide a substi-

tute for building-specific statical verification. The

tables apply to applications covered by Service

Classes 1 and 2 (NKL 1 and 2) in accordance with

DIN 1052, with a medium load duration.

6.1 Cross-sectional values and design values of mechanical resistanceTable 6.1 - Cross-sectional values and design values of mechanical resistance for preferred cross-sections in strength class C24 (grad-

ing class S10)1) for SC 1 and 2 with medium load durations

Solid timber cross-

section

w/d [cm]

Cross-sectional area

A [cm²]

Section modulus

Wy [cm3]

Moment of inertia

Iy [cm4]

Design bending

moment2)

MR,d

[kNm]

Design shear force

VR,d

[kN]

6/10 60 100 500 1.48 6.65

6/12 72 144 864 2.13 7.98

6/14 84 196 1372 2.89 9.30

6/16 96 256 2048 3.78 10.63

6/18 108 324 2916 4.79 11.96

6/20 120 400 4000 5.91 13.29

6/24 144 576 6912 8.51 15.95

8/12 96 192 1152 2.84 10.63

8/14 112 61 1829 3.86 12.41

8/16 128 341 2731 5.04 14.18

8/18 144 432 3888 6.38 15.95

8/20 160 533 5333 7.88 17.72

8/24 192 768 9216 11.34 21.27

10/10 100 167 833 2.46 11.08

10/16 160 427 3413 6.30 17.72

10/18 180 540 4860 7.98 19.94

10/20 200 667 6667 9.85 22.15

10/24 240 960 11520 14.18 26.58

12/12 144 288 1728 4.25 15.95

12/16 192 512 4096 7.56 21.27

12/20 240 800 8000 11.82 26.58

12/24 288 1152 13824 17.01 31.90

14/14 196 457 3201 6.75 21.71

14/20 280 933 9333 13.78 31.02

14/24 336 1344 16128 19.85 37.22

16/16 256 683 5461 10.08 28.36

16/20 320 1067 10667 15.75 35.45

16/24 384 1536 18432 22.69 42.54

1) Dimensioning values determined for medium load duration in Service Classes 1 and 2: Modification factor: kmod

= 0.8;

partial safety factor for solid timber: M

= 1.32) Flection along the strong axis (y-y)

6 Dimensioning reference tables

TAB. 6.1

DIN 1055-3: 2006-03

Action on structures - Part 3:

Self-weight and imposed load in building

DIN 1055-4: 2005-03


Wind loads

DIN 1055-5: 2005-07


Snow loads and ice loads

DIN 1055-100: 2001-03


Basis of design, safety concept and

design rules

The following dimensioning reference tables were

drawn up for KVH®, Duobalken® and Triobalken® in

strength class C24 (grading class S10 in accord-

ance with DIN 4074-1) using DIN 1052 as the basis.

As a general rule it is preferred cross-sections that

are referred to (bold print). The design loads apply

to typical cases in practice in accordance with DIN

1055, Parts 3 to 5. The decisive load combinations

used for dimensioning purposes are based on DIN

1055-100.

Overview of dimensioning reference tables

Table 6.1 Cross-sectional values and dimensioning values for stress resistance Page 17

Tables for ceiling beam cross-sections, C24 (S10), for beam spacing e

Table 6.2.1 Simply supported beams, e = 50.0 cm Page 18




Table 6.2.5 Double span beams, e = 50.0 cm Page 22




Table 6.3 Dimensioning values for load-bearing capacity Rc,d for one-piece posts, C24 (S10) Page 26

Tables for rafter cross-sections, C24 (S10)

Table 6.4.1 Simply supported beams, sk = 0.85 kN/m² Page 28

Table 6.4.2 Simply supported beams, sk = 1.10 kN/m² Page 28

Table 6.4.3 Double span beams, sk = 0.85 kN/m² Page 29

Table 6.4.4 Double span beams, sk = 1.10 kN/m Page 29


Ceiling beam cross-sections for simply supported beams

Footnotes to tables 6.2.1 and 6.2.2 1) Bold: Preferred cross-section KVH®, Duobalken® or Triobalken®beams

With gray background: Reduction in the cross-sectional height by 2 cm possible if Duobalken® or Triobalken®beams are used

Underlined: The specified cross-section applies only to the use of Duobalken® or Triobalken® beams

Italics: Cross-section not available (it is recommended that glued laminated timber GL24 be used)

2) Action:

gk: Characteristic permanent action (dead weight) in accordance with DIN 1055-1: 2002-06

qk,N

: Characteristic variable action (live loads) in accordance with DIN 1055-3: 2006-03

3) Dimensioning criteria (left or right column)

A Design bending moment MR,d

and design shear force VR,d

Final deflection in the characteristic dimensioning situation: wQ,inst

≤ l/300 und wfin

– wG,inst

≤ l/200

Deflection in the quasi-permanent dimensioning situation wfin

– w0 ≤ l/200

B Limitation of deflection to w = w

G,inst + ψ

2 × w

Q,inst ≤ 6 mm from quasi-permanent action as an additional criterion for the simpli-

fied vibration verification. A more exact vibration verification is recommended for individual cases.

TAB. 6.2.1 TAB. 6.2.2

qk,N

gk

l

Table 6.2.1 - Ceiling beam cross-sections, C24 (S10), simply supported beams, e = 50 cm for SC 1 and 2 with medium load durations

Simply supported beam, e = 50.0 cm C24 (S10)

Beam cross-section w/h [cm]1) in dependency on span l and loads g

k und q

k,N

Dead load2) gk

1.75 kN/m² 2.50 kN/m²

Live load2) qk,N

2.00 kN/m² 2.80 kN/m² 3.00 kN/m² 2.00 kN/m² 2.80 kN/m² 3.00 kN/m²

Dimensioning criterion3) A B A B A B A B A B A B

l = 3.00 m6/16 8/14

6/16 8/16

6/16 8/14

6/16 8/16

6/18 8/14

6/18 8/14

6/16 8/14

6/18 8/16

6/18 8/16

6/18 8/16

6/18 8/16

6/20 8/18

l = 3.25 m6/16 8/14

6/18 8/16

6/18 8/16

6/18 8/16

6/18 8/16

6/18 8/18

6/18 8/16

6/20 8/18

6/20 8/16

6/20 8/18

6/20 8/18

6/20 8/18

l = 3.50 m6/18 8/16

6/20 8/18

6/20 8/16

6/20 8/18

6/20 8/18

6/20 8/18

6/20 8/16

6/228/20

6/20 8/18

6/22 8/20

8/228/20

8/228/20

l = 3.75 m6/18 8/16

6/228/20

6/20 8/16

6/228/20

6/228/20

6/228/20

6/20 8/18

6/24 8/22

6/228/20

6/24 8/22

6/228/20

6/24 8/22

l = 4.00 m8/18 8/22 8/20 8/22 8/20 8/22 8/18 8/24 8/20 8/24 8/20 8/24

10/16 10/20 10/18 10/20 10/18 10/22 10/18 10/22 10/18 10/22 10/18 10/22

l = 4.25 m8/18 8/24 8/20 8/24 8/20 8/24 8/20 8/24 10/20 10/24 8/22 10/2410/16 10/22 10/18 10/22 10/18 10/22 10/18 10/24 12/18 12/22 10/20 12/24

l = 4.50 m10/18 10/24 10/20 10/24 10/20 10/24 10/20 10/24 10/20 12/24 8/24 12/24

12/16 12/22 12/18 12/22 12/18 12/22 12/18 12/24 12/18 14/24 10/22 14/24

l = 4.75 m10/18 12/24 10/20 12/24 10/20 12/24 10/22 14/24 10/22 14/24 8/24 12/26

12/18 14/22 12/18 14/24 12/18 14/24 12/20 16/24 12/20 16/24 10/22 14/26

l = 5.00 m10/1812/20

12/24 14/24

10/22 12/20

12/26 14/24

10/2212/20

12/26 14/24

10/2212/20

14/26 16/24

10/2212/20

14/26 16/26

10/2412/22

14/26 16/26

l = 5.25 m10/20 14/26 10/22 14/26 10/22 14/26 10/22 14/28 10/24 14/28 10/24 14/28

12/20 16/24 12/20 16/26 12/20 16/28 12/22 16/26 12/22 16/28 12/22 16/26

l = 5.50 m12/20 14/20

14/26 16/26

12/22 14/20

14/28 16/26

10/24 12/24

14/28 16/26

10/2412/22

14/3016/28

12/22 14/22

14/3016/28

12/2414/22

14/3016/28

Footnotes see page 19

Table 6.2.2 - Ceiling beam cross-sections, C24 (S10), simply supported beams, e = 62.5 cm for SC 1 and 2 with medium load durations



k und q

k,N

Dead load2) gk

1.75 kN/m² 2.50 kN/m²

Live load2) qk,N



l = 3.00 m6/18 8/16

6/18 8/16

6/20 8/18

6/18 8/16

6/20 8/18

6/20 8/18

6/20 8/18

l = 3.25 m6/20 8/18

6/20 8/18

6/20 8/18

6/20 8/16

6/228/20

6/228/18

6/228/20

6/22 8/20

l = 3.50 m6/228/18

6/228/20

6/228/18

6/228/20

6/228/20

6/20 8/18

6/24 8/22

6/20 8/20

6/24 8/22

6/24 8/22

l = 3.75 m6/228/20

6/24 8/22

6/228/20

6/24 8/22

6/24 8/22

8/20 10/18

8/24 10/22

6/24 8/22

8/24 10/22

8/2210/20

8/24 10/22

l = 4.00 m8/22

10/208/24 10/22

6/2210/20

8/24 10/22

8/22 10/20

8/24 10/22

6/24 8/22

8/24 10/24

8/22 10/20

10/24 12/22

8/24 10/20

8/2610/24

l = 4.25 m10/2012/18

10/2412/22

8/2210/20

10/2412/22

8/24 10/20

10/24 12/24

8/2210/20

10/24 12/24

8/24 10/22

12/24 14/24

8/24 10/22

12/24 14/24

l = 4.50 m10/22 12/24 8/24 12/24 8/24 10/24 8/24 14/24 10/22 14/24 10/24 14/24 12/20 14/24 10/22 14/24 10/22 12/24 10/22 16/24 12/20 16/24 12/22 16/24

l = 4.75 m8/20 14/24 10/22 14/24 10/24 12/26 8/24 14/26 10/24 14/26 10/24 14/28 10/22 16/24 12/20 16/24 12/22 14/24 10/22 16/24 12/22 16/26 12/22 16/26

l = 5.00 m8/2410/22

14/26 16/26

10/2412/22

14/26 16/26

10/2412/22

12/26 14/26

10/2412/22

14/26 16/26

12/2414/22

14/28 16/28

12/2414/22

14/2816/28

l = 5.25 m12/22 14/28 12/22 14/28 12/24 14/30 10/24 14/30 12/24 14/30 12/24 14/32 14/20 16/26 14/22 16/26 14/22 16/28 12/22 16/28 14/22 16/30 14/22 16/30

l = 5.50 m12/2414/22

14/30 16/28

12/24 14/20

14/30 16/28

14/2416/22

14/30 16/28

12/2414/22

14/32 16/30

14/2416/22

14/32 16/30

14/24 16/24

14/3416/32



TAB. 6.2.3 TAB. 6.2.4




k und q

k,N

Dead load2) gk

1.75 kN/m² 2.50 kN/m²

Live load2) qk,N



l = 3.00 m6/18 8/16

6/18 8/18

6/20 8/18

6/20 8/18

6/20 8/18

6/20 8/18

6/228/20

6/228/20

l = 3.25 m6/20 8/18

6/228/20

6/228/20

6/228/18

6/228/20

6/24 8/20

6/24 8/22

l = 3.50 m6/228/18

8/20 10/20

6/24 8/20

6/24 8/20

6/24 8/22

6/24 8/20

8/2210/22

8/2210/20

8/24 10/22

8/2210/20

8/24 10/22

l = 3.75 m6/228/20

8/22 10/22

8/2210/20

8/24 10/22

6/24 8/22

8/24 10/22

8/2210/20

8/24 10/22

8/24 10/20

8/24 10/24

8/24 10/22

8/24 10/24

l = 4.00 m6/248/22

10/22 12/22

8/24 10/20

10/2412/22

8/24 10/22

10/2412/22

8/2210/20

10/24 12/24

8/24 10/22

12/2414/22

10/2412/22

10/2612/24

l = 4.25 m8/2010/20

10/22 14/22

8/24 10/22

12/2414/22

10/2412/22

12/24 14/24

8/24 10/22

14/2416/22

10/2412/22

12/26 14/24

10/2412/22

12/2614/24

l = 4.50 m8/24 10/22

14/2416/22

10/2412/22

14/2416/26

10/2412/22

14/24 16/24

10/24 12/20

14/26 16/24

12/22 14/22

14/26 16/26

12/2414/22

14/26 16/26

l = 4.75 m8/24 14/26 10/24 14/26 12/24 14/28 10/24 14/28 12/24 14/28 14/24 14/28 10/22 16/24 12/22 16/26 14/22 16/26 12/20 16/26 14/22 16/28 16/22 16/28

l = 5.00 m10/24 14/28 12/24 14/28 14/24 14/28 12/24 14/30 14/24 16/28 14/24 14/30 12/22 16/26 14/24 16/26 16/22 16/28 14/22 16/28 16/22 16/30 16/24 16/30




k und q

k,N

Dead load2) gk

1.75 kN/m² 2.50 kN/m²

Live load2) qk,N



l = 3.00 m6/20

8/16

6/20

8/18

6/22

8/18

6/22

8/20

6/20

8/18

6/20

8/20

6/22

8/20

6/24

8/20

l = 3.25 m6/20

8/18

6/22

8/20

6/22

8/20

6/24

8/20

6/22

8/20

6/24

8/22

6/24

8/22

8/22

10/20

l = 3.50 m6/22

8/22

6/24

8/22

6/24

8/22

8/22

10/20

6/24

8/20

8/24

10/22

8/22

10/20

8/24

10/22

l = 3.75 m6/24

8/20

8/24

10/22

8/22

10/20

8/24

10/22

8/24

10/22

8/22

10/20

8/24

10/24

8/24

10/22

8/24

10/24

10/24

12/22

10/24

12/24

l = 4.00 m8/22

10/20

10/24

12/22

8/24

10/22

10/24

12/22

10/24

12/20

10/24

12/24

8/24

10/22

10/24

12/24

10/24

12/22

10/26

12/24

10/24

12/22

12/26

14/24

l = 4.25 m8/24

10/22

12/24

14/22

10/24

12/22

12/24

14/24

10/24

12/22

12/26

14/24

10/22

12/20

14/24

16/24

10/24

12/22

12/28

14/26

12/24

14/22

14/26

16/24

l = 4.50 m8/24

10/22

14/24

16/24

10/24

12/22

14/24

16/24

12/24

14/22

14/26

16/24

10/24

12/22

14/26

16/26

12/24

14/22

14/28

16/26

12/24

14/22

14/28

16/26

l = 4.75 m10/24 14/26 12/24 14/26 12/24 14/28 12/24 14/28 14/24 14/30 14/24 14/3012/22 16/26 14/22 16/26 14/22 16/26 14/22 16/28 16/22 16/28 16/24 16/28

l = 5.00 m10/24

12/22

14/28

16/26

12/24

14/22

14/28

16/28

14/24

16/24

14/30

16/28

12/24

14/22

14/30

16/30

14/24

16/24

14/32

16/30

14/26

16/24

14/32

16/30


With gray background: Reduction in the cross-sectional height by 2 cm possible if Duobalken® or Triobalken®beams are used

Underlined: The specified cross-section applies only to the use of Duobalken® or Triobalken® beams


2) Action:


qk,N






≤ l/300 und wfin

– wG,inst

≤ l/200


– w0 ≤ l/200


G,inst + ψ

2 × w




Ceiling beam cross-sections for double span beams



2) Action:


qk,N






≤ l/300 und wfin

– wG,inst

≤ l/200


– w0 ≤ l/200


G,inst + ψ

2 × w



Double span beam e = 50.0 cm C24 (S10)


k und q

k,N

Dead load2) gk

1.75 kN/m² 2.50 kN/m²

Live load2) qk,N

2.00 kN/m² 2.80 kN/m² 3.00 kN/m² 2.00 kN/m² 2.80 kN/m² 3,00 kN/m²


l = 3.00 m6/16 8/14

6/16 8/14

6/18 8/16

6/16 8/14

6/18 8/16

6/18 8/16

l = 3.25 m6/16 8/14

6/18 8/16

6/20 8/16

6/18 8/16

6/20 8/16

6/20 8/18

l = 3.50 m6/18 8/16

6/20 8/16

6/20 8/18

6/18 8/16

6/20 8/18

6/228/18

l = 3.75 m6/18 8/16

6/20 8/18

6/228/20

6/20 8/18

6/228/20

6/24 8/20

l = 4.00 m6/20 8/18

6/22 8/20

6/24 8/20

6/22 8/18

6/24 8/20

6/24 8/22

l = 4.25 m6/228/18

6/24 8/20

6/24 8/22

6/22 8/20

6/24 8/22

8/2210/20

l = 4.50 m6/20 8/18

6/228/20

6/24 8/22

8/2210/20

6/24 8/20

6/24 8/22

8/2210/20

8/24 10/22

l = 4.75 m6/228/20

8/2210/20

8/2210/20

8/24 10/22

8/2210/20

8/24 10/22

8/24 10/22

10/24 12/22

l = 5.00 m6/24 8/22

10/2412/22

8/24 10/22

10/2212/20

10/22 12/22

8/24 10/22

10/2212/20

10/24 12/22

10/2412/22

10/24 12/24

l = 5.25 m8/22

10/2010/22 12/22

8/24 10/22

8/26 10/24

10/2412/22

10/24 12/24

8/24 10/22

10/24 12/24

10/2412/22

10/24 12/24

12/2414/22

12/24 14/24

l = 5.50 m8/24 10/22

10/2412/22

10/2412/22

12/22 14/22

12/24 14/24

10/22 12/20

12/24 14/24

12/22 14/22

12/26 14/24

14/22 16/22

14/24 16/24

l = 5.75 m10/2212/20

12/2414/22

10/2412/22

10/26 12/24

14/22 16/22

14/24 16/24

10/22 12/22

14/24 16/24

14/22 16/20

14/26 16/24

14/2416/22

14/26 16/24

l = 6.00 m10/22 12/20

14/2416/22

12/2414/22

12/26 14/24

14/2416/22

14/26 16/24

12/22 14/22

14/26 16/24

14/2416/22

14/26 16/26

14/2416/22

14/28 16/26


qk,N

gk

ll

TAB. 6.2.5 TAB. 6.2.6

Table 6.2.5 - Ceiling beam cross-sections, C24 (S10), double span beams, e = 50.0 cm for SC 1 and 2 with medium load durations Table 6.2.6 - Ceiling beam cross-sections, C24 (S10), double span beams, e = 62.5 cm for SC 1 and 2 with medium load durations



k und q

k,N

Dead load2) gk

1.75 kN/m² 2.50 kN/m²

Live load2) qk,N



l = 3.00 m6/16 8/14

6/18 8/16

6/18 8/16

6/18 8/16

6/20 8/18

6/20 8/18

l = 3.25 m6/18 8/16

6/20 8/18

6/20 8/20

6/20 8/18

6/228/18

6/228/20

l = 3.50 m6/20 8/18

6/22 8/18

6/22 8/20

6/20 8/18

6/228/20

6/24 8/22

l = 3.75 m6/20 8/18

6/228/20

6/24 8/22

6/228/20

6/24 8/22

8/2210/20

l = 4.00 m6/228/20

6/24 8/22

6/24 8/22

6/24 8/20

8/2210/20

8/24 10/22

l = 4.25 m6/24 8/20

8/2210/20

8/2210/20

8/2210/20

8/24 10/22

10/24 12/22

l = 4.50 m6/24 8/22

8/24 10/22

8/24 10/22

8/24 10/22

10/2212/20

10/24 12/22

l = 4.75 m8/22

10/208/22

10/228/24 10/22

10/2412/22

8/24 10/22

8/24 10/24

10/2412/22

12/2414/22

l = 5.00 m8/24 10/22

10/2412/22

12/2214/20

12/2214/22

10/24 12/24

12/2414/22

12/2414/22

12/24 14/24

l = 5.25 m10/2212/20

10/2412/22

10/24 12/22

12/2414/22

12/2414/22

12/24 14/24

10/24 12/24

12/24 14/24

12/2414/22

14/24 16/24

12/2414/22

12/26 14/24

l = 5.50 m10/2412/22

12/24 14/24

12/2414/22

14/24 16/24

12/2414/22

14/24 16/24

12/2414/22

14/24 16/24

14/2416/22

14/26 16/24

14/24 16/24

14/26 16/26

l = 5.75 m12/2214/20

14/24 16/24

12/2414/22

14/26 16/24

14/2416/22

14/26 16/24

12/2414/22

14/26 16/26

14/24 16/24

14/28 16/26

14/26 16/24

14/28 16/26

l = 6.00 m14/22 16/20

14/26 16/24

14/2416/22

14/26 16/26

14/2416/22

14/28 16/26

14/2416/22

14/28 16/26

14/26 16/24

14/28 16/28

14/28 16/26

14/3016/28




2) Action:


qk,N






≤ l/300 und wfin

– wG,inst

≤ l/200


– w0 ≤ l/200


G,inst + ψ

2 × w



TAB. 6.2.7 TAB. 6.2.8

TTab. 6.2.7 - Ceiling beam cross-sections, C24 (S10), double span beams, e = 75.0 cm for SC 1 and 2 with medium load durations



k und q

k,N

Dead load2) gk

1.75 kN/m² 2.50 kN/m²

Live load2) qk,N



l = 3.00 m6/18

8/16

6/20

8/18

6/20

8/18

6/20

8/18

6/22

8/18

6/22

8/20

l = 3.25 m6/20

8/18

6/22

8/18

6/22

8/20

6/22

8/18

6/24

8/20

6/24

8/20

l = 3.50 m6/22

8/20

6/24

8/20

6/24

8/20

6/22

8/20

8/22

10/20

8/24

10/20

l = 3.75 m6/22

8/20

6/24

8/22

8/22

10/20

6/24

8/22

8/24

10/22

8/24

10/22

l = 4.00 m6/24

8/22

8/24

10/20

8/24

10/22

8/22

10/20

8/24

10/22

10/22

12/20

l = 4.25 m8/22

10/20

8/24

10/22

10/22

12/20

8/24

10/22

10/24

12/22

10/24

12/22

10/24

12/24

l = 4.50 m8/24

10/22

10/24

12/22

10/24

12/22

10/22

12/20

10/24

12/22

12/24

14/22

l = 4.75 m8/24

10/22

10/24

12/22

12/24

14/22

10/24

12/22

10/24

12/24

12/24

14/22

14/24

16/22

l = 5.00 m10/24

12/22

10/24

12/24

12/24

14/22

12/24

14/22

12/24

14/22

12/24

14/24

14/24

16/22

14/24

16/24

14/24

16/24

14/26

16/24

l = 5.25 m10/24

12/22

12/24

14/24

12/24

14/22

14/24

16/24

14/24

16/22

14/24

16/24

12/24

14/22

14/24

16/24

14/24

16/24

14/26

16/24

14/26

16/24

l = 5.50 m12/24

14/22

14/24

16/24

14/24

16/22

14/26

16/24

14/26

16/24

14/26

16/26

14/22

16/20

14/26

16/26

14/26

16/24

14/28

16/26

14/28

16/26

l = 5.75 m12/24

14/22

14/26

16/24

14/24

16/24

14/28

16/26

14/26

16/24

14/28

16/26

14/24

16/24

14/28

16/26

14/26

16/26

14/28

16/28

14/28

16/26

14/30

16/28

l = 6.00 m14/24

16/22

14/28

16/26

14/26

16/24

14/28

16/28

14/26

16/26

14/30

16/28

14/26

16/24

14/30

16/28

14/28

16/26

14/30

16/30

14/30

16/28

14/32

16/30

Table 6.2.8 - Ceiling beam cross-sections, C24 (S10), double span beams, e = 83.3 cm for SC 1 and 2 with medium load durations



k und q

k,N

Dead load2) gk

1.75 kN/m² 2.50 kN/m²

Live load2) qk,N



l = 3.00 m6/20 8/16

6/228/18

6/228/20

6/20 8/18

6/228/20

6/24 8/20

l = 3.25 m6/20 8/18

6/22 8/20

6/24 8/20

6/228/20

6/24 8/22

8/2210/20

l = 3.50 m6/228/20

6/24 8/22

8/24 10/20

6/24 8/22

8/2210/20

8/24 10/22

l = 3.75 m6/24 8/20

8/2210/20

8/22 10/22

8/22 10/20

8/24 10/22

10/2212/20

l = 4.00 m8/22

10/208/24 10/22

8/24 10/22

8/24 10/22

10/24 12/22

10/24 12/22

l = 4.25 m8/24 10/22

10/24 12/22

10/24 12/22

10/22 12/20

10/24 12/22

12/24 14/22

l = 4.50 m8/24 10/22

10/2412/22

12/2414/22

10/24 12/20

10/2412/22

12/2414/22

14/2416/22

l = 4.75 m10/2412/22

12/2414/22

14/2216/22

12/2414/22

14/2416/22

14/24 16/24

l = 5.00 m10/2412/22

10/24 12/24

12/24 14/24

14/24 16/24

12/2414/22

14/24 16/24

14/24 16/24

14/26 16/24

14/26 16/24

l = 5.25 m12/24 14/24

14/2416/22

14/24 16/24

14/26 16/24

14/24 16/22

14/26 16/24

14/26 16/24

14/26 16/26

14/28 16/26

l = 5.50 m12/2414/22

14/26 16/24

14/26 16/24

14/26 16/26

14/28 16/26

14/24 16/24

14/28 16/26

14/26 16/26

14/28 16/26

14/28 16/26

14/28 16/28

l = 5.75 m14/2416/22

14/26 16/26

14/26 16/24

14/28 16/26

14/28 16/26

14/26 16/24

14/28 16/28

14/28 16/26

14/3016/26

14/3016/28

14/30 16/30

l = 6.00 m14/24 16/24

14/28 16/26

14/28 16/26

14/3016/28

14/3016/28

14/30 16/30

14/28 16/26

14/30 16/30

14/30 16/30

14/32 16/30

14/32 16/30

14/32 16/32



6.3 Post cross-sections 6.4 Rafter cross-sections

1)Dimensioning values determined for

buckling along the weak (decisive) axis

for medium load duration (residential,

office buildings) in Service Classes 1

and 2:

Modification factor: kmod

= 0.8; Partial

safety factor for solid timber: M = 1.3

2) Simplified calculation of design com-

pression force Rc,d on the basis of the

following assumptions:Safety factor on

the load side: G =

Q = 1.5;

combination factor ψo = 1.0

Footnotes to Tables 6.4.x1) Bold: Preferred cross-section KVH® or Duobalken®, Triobalken® beams

Action:


sk: Characteristic value for snow load on the ground in accordance with DIN 1055-5: 2005-07

qW: Wind pressure in accordance with DIN 1055-4: 2005-03

(qW

= 0.9 kN/m² corresponds to wind zone 2 up to h = 10 m)

Single-piece post

s k

Fc,d

Table 6.3.1 - Design values of compression force parallel to the grain Rc,d

for single-piece posts, C24 (S10),

with articulated support on both sides1), for SC 1 and 2 with medium load durations

C24 (S10) Rc,d

[kN] in dependency on buckling length sk [m]2)

Cross-sections

w/h [cm]2.50 3.00 3.50 4.00 4.50 5.00 5.50 6.00

6/10 7.90 5.57 4.13 3.19 2.53 2.06 1.71 1.44

6/12 9.48 6.69 4.96 3.83 3.04 2.47 2.05 1.73

6/14 11.07 7.80 5.79 4.46 3.55 2.88 2.39 2.02

6/16 12.65 8.91 6.61 5.10 4.05 3.30 2.73 2.30

6/18 14.23 10.03 7.44 5.74 4.56 3.71 3.08 2.59

6/20 15.81 11.14 8.27 6.38 5.07 4.12 3.42 2.88

6/24 18.97 13.37 9.92 7.65 6.08 4.95 4.10 3.46

8/12 21.70 15.44 11.52 8.91 7.10 5.78 4.80 4.05

8/14 23.32 18.02 13.44 10.40 8.28 6.75 5.60 4.73

8/16 28.94 20.59 15.36 11.89 9.46 7.71 6.41 5.40

8/18 32.56 23.17 17.28 13.37 10.65 8.68 7.21 6.08

8/20 36.17 25.74 19.20 14.86 11.83 9.64 8.01 6.75

8/24 43.41 30.89 23.04 17.83 14.20 11.57 9.61 8.11

10/10 33.70 24.36 18.32 14.24 11.37 9.29 7.72 6.52

10/16 53.92 38.98 29.31 22.78 18.19 14.86 12.36 10.44

10/18 60.66 43.86 32.97 25.63 20.47 16.71 13.90 11.74

10/20 67.40 48.73 36.63 28.47 22.74 18.57 15.45 13.05

10/24 80.87 58.48 43.96 34.17 27.29 22.29 18.54 15.66

12/12 65.31 48.52 36.93 28.89 23.17 18.97 15.81 13.37

12/16 87.08 64.70 49.24 38.52 30.89 25.29 21.08 17.83

12/20 108.85 80.87 61.55 48.15 38.61 31.62 26.35 22.29

12/24 130.61 97.05 73.86 57.78 46.33 37.94 31.62 26.74

14/14 109.79 85.13 66.05 52.18 42.07 34.57 28.88 24.47

14/20 156.85 121.61 94.35 74.54 60.10 49.38 41.25 34.95

14/24 188.22 145.94 113.22 89.44 72.12 59.26 49.50 41.94

16/16 164.74 134.84 107.65 86.27 70.11 57.88 48.50 41.19

16/20 205.92 168.55 134.56 107.83 87.63 72.35 60.63 51.48

16/24 247.10 202.23 161.47 129.40 105.16 86.82 72.75 61.78

Preliminary remarks: The following dimensioning reference tables were developed for rafters in purlin

roof structures. The values for the load action (wind and snow loads) applied here are based on roof areas

larger than 10 m2. Additional structures on the roof such as, e.g. photovoltaic units or snow guards, and

trimmings, e.g. for skylights, must be taken into consideration separately in the building-specific verification.

TAB. 6.3.1


Rafter cross-sections for simply supported beams

TAB. 6.4.2

TAB. 6.4.4

Rafter cross-sections for double span beams

Rafter in the form of a simply

supported beam

sk

qw

gk

l

α

Rafter in the form of a simply

supported beam

sk

qw

gk

l

α

ks

gk

qw

l l

α

Rafter in the form of a

double span beam

(identical spans)

ks

gk

qw

l l

α

Rafter in the form of a

double span beam

(identical spans)

TAB. 6.4.1 TAB. 6.4.3

Tab. 6.4.1 - Rafter cross-sections, C24 (S10), sk = 0.85 kN/m² for SC 1 and 2 with medium load durations

Simply supported beam - C24 (S10) g

k = 1.20 kN/m²

sk = 0.85 kN/m²

qW = 0.90 kN/m²

Rafter cross-section w/h [cm]1) in dependency on roof pitch, rafter spacing e and span l

a = 5° - 25° a = 26° - 35°

Rafter spacing [m] 0.625 0.75 0.833 0.625 0.75 0.833

Max

imum

spa

n (a

rea)

l = 2.50 m6/14 8/12

6/14 8/12

6/14 8/12

6/14 8/12

6/14 8/14

6/14 8/14

l = 3.00 m6/16 8/14

6/16 8/14

6/16 8/14

6/16 8/16

6/18 8/16

6/18 8/16

l = 3.50 m6/18 8/16

6/18 8/18

6/20 8/18

6/20 8/18

6/20 8/18

6/20 8/18

l = 4.00 m6/20 8/18

6/228/20

6/228/20

6/22 8/20

6/228/20

6/24 8/22

l = 4.50 m6/22 8/20

6/248/22

6/248/22

6/248/22

6/26 8/24

6/26 8/24

Roof pitch a = 36° - 45° a = 46° - 55°

Rafter spacing (m) 0.625 0.75 0.833 0.625 0.75 0.833

Max

imum

spa

n (a

rea)

l = 2.50 m6/16 8/14

6/16 8/14

6/16 8/14

6/18 8/16

6/18 8/18

6/20 8/18

l = 3.00 m6/18 8/16

6/20 8/18

6/20 8/18

6/22 8/20

6/22 8/20

6/22 8/20

l = 3.50 m6/22 8/20

6/22 8/20

6/22 8/20

6/24 8/22

8/2410/22

8/2410/22

l = 4.00 m6/24 8/22

6/26 8/24

6/26 8/24

10/2412/22

10/26 12/24

10/26 12/24

l = 4.50 m8/2410/22

8/26 10/24

8/26 10/24

12/26 14/24

12/26 16/24

14/26 16/24

Table 6.4.2 - Rafter cross-sections, C24 (S10), sk = 1.10 kN/m² for SC 1 and 2 with medium load durations

Simply supported beam - C24 (S10)g

k = 1.20 kN/m²

sk = 1.10 kN/m²

qW = 0.90 kN/m²


a = 5° - 25° a = 26° - 35°

Rafter spacing [m] 0.625 0.75 0.833 0.625 0.75 0.833

Max

imum

spa

n (a

rea)

l = 2.50 m6/14 8/12

6/14 8/12

6/14 8/12

6/14 8/14

6/14 8/14

6/16 8/14

l = 3.00 m6/16 8/14

6/16 8/16

6/16 8/16

6/18 8/16

6/18 8/16

6/18 8/16

l = 3.50 m6/18 8/18

6/20 8/18

6/20 8/18

6/20 8/18

6/20 8/18

6/20 8/20

l = 4.00 m6/228/20

6/228/20

6/228/20

6/228/20

6/24 8/22

6/24 8/22

l = 4.50 m6/248/22

6/248/22

6/248/22

6/26 8/24

6/26 8/24

6/26 8/24

Roof pitch a = 36° - 45° a = 46° - 55°

Rafter spacing (m) 0.625 0.75 0.833 0.625 0.75 0.833

Max

imum

spa

n (a

rea)

l = 2.50 m6/16 8/14

6/16 8/14

6/16 8/14

6/18 8/16

6/18 8/18

6/20 8/18

l = 3.00 m6/18 8/18

6/20 8/18

6/20 8/18

6/228/20

6/228/20

6/228/20

l = 3.50 m6/228/20

6/22 8/20

6/228/20

6/268/24

6/26 8/24

8/2410/22

l = 4.00 m6/24 8/22

6/26 8/24

6/26 8/24

10/24 12/22

10/26 12/24

10/26 12/24

l = 4.50 m8/26

10/248/26

10/248/26

10/2410/26 14/24

12/26 16/24

14/26 16/24


Double span beam - C24 (S10) g

k = 1.20 kN/m²

sk = 0.85 kN/m²

qW = 0.90 kN/m²


a = 5° - 25° a = 26° - 35°

Rafter spacing [m] 0.625 0.75 0.833 0.625 0.75 0.833

Max

imum

spa

n (a

rea)

l = 2.50 m 6/10 6/12 6/12 6/12 6/126/14 8/12

l = 3.00 m 6/126/14 8/12

6/14 8/12

6/14 8/12

6/14 8/14

6/16 8/14

l = 3.50 m6/14 8/12

6/16 8/14

6/18 8/16

6/16 8/14

6/18 8/16

6/18 8/16

l = 4.00 m6/16 8/14

6/18 8/16

6/20 8/16

6/16 8/14

6/20 8/18

6/20 6/18

l = 4.50 m6/18 8/16

6/20 8/18

6/22 8/18

6/20 8/18

6/22 8/20

6/22 8/20

l = 5.00 m6/20 8/18

6/22 8/20

6/24 8/20

6/22 8/20

6/24 8/22

8/24 10/20

Roof pitch a = 36° - 45° a = 46° - 55°

Rafter spacing (m) 0.625 0.75 0.833 0.625 0.75 0.833

Max

imum

spa

n (a

rea)

l = 2.50 m 6/126/14 8/12

6/14 8/12

6/14 8/12

6/16 8/14

6/16 8/14

l = 3.00 m6/14 8/12

6/16 8/14

6/16 8/14

6/16 8/16

6/18 8/16

6/18 8/16

l = 3.50 m6/16 8/14

6/18 8/16

6/20 8/16

6/20 8/18

6/20 8/18

6/22 8/20

l = 4.00 m6/18 8/16

6/20 8/18

6/22 8/18

6/22 8/20

6/24 8/20

6/24 8/22

l = 4.50 m6/22 8/18

6/24 8/20

6/24 8/22

6/24 8/22

8/24 10/22

8/24 10/22

l = 5.00 m6/24 8/20

6/268/22

8/24 10/22

8/24 10/22

10/24 12/22

10/24 12/22


Double span beam - C24 (S10) g

k = 1.20 kN/m²

sk = 1.10 kN/m²

qW = 0.90 kN/m²


a = 5° - 25° a = 26° - 35°

Rafter spacing [m] 0.625 0.75 0.833 0.625 0.75 0.833

Max

imum

spa

n (a

rea)

l = 2.50 m 6/12 6/126/14 8/12

6/126/14 8/12

6/14 8/12

l = 3.00 m6/14 8/12

6/14 8/12

6/16 8/14

6/14 8/12

6/16 8/14

6/16 8/14

l = 3.50 m6/16 8/14

6/18 8/14

6/18 8/16

6/16 8/14

6/18 8/16

6/18 8/16

l = 4.00 m6/18 8/16

6/20 8/16

6/20 8/18

6/18 8/16

6/20 8/18

6/22 8/18

l = 4.50 m6/20 8/18

6/22 8/18

6/22 8/20

6/20 8/18

6/22 8/20

6/24 8/20

l = 5.00 m6/22 8/20

6/24 8/20

8/24 10/20

6/24 8/20

8/22 10/20

8/24 10/20

Roof pitch a = 36° - 45° a = 46° - 55°

Rafter spacing (m) 0.625 0.75 0.833 0.625 0.75 0.833

Max

imum

spa

n (a

rea)

l = 2.50 m 6/126/14 8/12

6/14 8/12

6/14 8/12

6/16 8/14

6/16 8/14

l = 3.00 m6/14 8/12

6/16 8/14

6/16 8/14

6/16 8/16

6/18 8/16

6/20 8/16

l = 3.50 m6/16 8/14

6/18 8/16

6/20 8/16

6/20 8/18

6/20 8/18

6/22 8/20

l = 4.00 m6/20 8/18

6/20 8/18

6/22 8/20

6/22 8/20

6/24 8/20

8/24 10/20

l = 4.50 m6/22 8/18

6/24 8/20

6/24 8/22

6/24 8/22

8/24 10/22

8/24 10/22

l = 5.00 m6/24 8/22

8/22 10/20

8/24 10/22

8/24 10/22

10/24 12/22

10/24 12/22


References:

[2] Kuhlenkamp, Hallinger: Kommentar zur

ATV DIN 18334 Zimmer- und Holzbauarbei-

ten; Publisher: Bund Deutscher Zimmer-

meister im Verlag Weka Medien GmbH,

Kissingen, 2005

[3] Radovic, B.: Unempfindlichkeit von tech-

nisch getrocknetem Holz gegen Insekten;

in Informationsdienst HOLZ spezial, No-

vember 2008; Publisher: Holzabsatzfonds,

Bonn 2008.

7 Context provided by current standards

KVH® structural timber and Duobalken® and

Triobalken® laminated beams have provided

proven service for many years in meeting the

increasing requirements associated with mod-

ern timber construction. The requirement for

dry and dimensionally stable construction tim-

ber to be used for carpentry and constructional

timber works is now specified in all of the main

building regulations.

DIN 4074-1: Strength grading of wood - Part 1:

Sawn coniferous timber

The grading criteria set out in DIN 4074-1 for clas-

sifying the load-bearing capacity of construction

timber are based on timber dimensions related to

an official value of moisture content of um = 20 %,

in other words dry timber. If the timber is not

graded in a dry state (TS labeling), suitable allow-

ance has to be made, e.g. by sawing to oversizes.

Even then, the grading criteria of cracks caused by

shrinking and of curvature still remain unaccoun-

ted for. Given that the only means of checking

with certainty that all the grading criteria are met

is if the wood is dry, the timber has to be carefully

re-graded by the person handling the wood im-

mediately prior to installation and rejected where

necessary, because that person is duty-bound only

to install timber which has the "required equilib-

rium moisture content", which means dry timber.

If the timber were to be installed in a semi-dry or

moist state, it would have to be examined in what

as a rule would be a dry equilibrium state to see

if any strength-reducing cracks had developed,

which would represent an unacceptable situa-

tion. The time and effort that this requires can be

avoided if KVH® and Duobalken® and Triobalken®

are used, because the timber used in these

products is only ever graded when dry and meets

more stringent quality criteria than those speci-

fied in DIN 4074-1.

Bauregelliste A (Construction Products List A):

Labeling with the "Ü" mark

Ever since 2004, German Bauregelliste A (Con-

struction Products List A) specifies that grad-

ing standard DIN 4074-1 has to be used as the

reference standard for the inspection mark. This

means that only solid timber which has been

graded when completely dry and bears an "Ü"

inspection mark containing specific reference to

DIN 4074-1 is unequivocally a regulated construc-

tion product. KVH® structural timber also has an

additional symbol in the "Ü" mark to indicate the

certifying body, because the product is finger-

jointed. Solid timber without finger-joints will in

future be permitted under European regulations

to bear a CE mark of conformity as an alternative.

Duobalken® and Triobalken® beams also have to

be labeled with the "Ü" mark, but instead of refer-

ence to DIN 4074-1 these labels have to contain

the approval number and the symbol of the

certifying body.

At present there is no European technical stand-

ard, which means that there is no associated CE

mark of conformity available either.

ATV DIN 18334: VOB/C

Carpentry and constructional timber works

It is a requirement of the German general techni-

cal specifications for building works for carpentry

and timber construction works (DIN 18334) (All-

gemeine Technische Vertragsbedingungen für Bau-

leistungen [ATV] für Zimmer- und Holzbauarbei-

ten) that construction timber made of sawn soft-

wood must always be dry before it is installed. The

2000 version of this regulation introduced more

stringent requirements for timber house construc-

tion with regard to moisture content (um ≤ 18 %),

dimensional stability and type of cutting.

According to the commentary on the standard [2],

internal timber in multi-storey timber buildings

has to have a lower moisture content because of

the settlement characteristics of such buildings.

This requirement is particularly topical now that

the German Model Building Regulations (Muster-

bauordnung [MBO] 2002) have been incorporated

in the building regulations of the individual fede-

ral states and allow the principle of permitting

the erection of timber construction buildings of

up to five storeys in height.

DIN 1052 – Design of timber structures

The dimensioning standard for timber construc-

tion is another standard which requires the instal-

lation of dry timber for Service Classes 1 and 2

(see the table on page 7), on the basis that this is

required to reduce cracks caused by shrinking and

changes in dimensions. Furthermore, it is only

possible to match softwood products between

the grading classes specified in DIN 4074-1 and

the strength classes specified in DIN 1052 if the

timber has been graded when dry (TS) (see the

table on page 11). It also has to be taken into

consideration that the characteristic strengths

used for the strength classes only partially ac-

count for cracking.

Caution is required when installing timber with-

out suitably adjusted moisture content

Where timber with a much higher moisture content

than the required equilibrium moisture content is

installed, DIN 1052 requires that the timber must

be able to dry out afterwards and that the struc-

tural timber components themselves, along with

all adjacent building components, must be resist-

ant to deformation through the shrinkage which

can be associated with drying. The construction

work required here, and the greater risk of build-

ing damage, can be avoided if KVH® structural

timber and Duobalken® and Triobalken® are used.

Example: A wooden ceiling beam with a moisture

content for internal timber of um = 20% can dry

out to 6% in the climate of a heated residential

building. For a beam of 24 cm in height a 14%

change in moisture content would result in a

mean shrinkage ratio of 8 mm. The concomitant

settlement has to be accommodated without

any damage occurring. It would be better to use

dry timber from the outset, e.g. Duobalken or

Triobalken beams with a maximum um = 15%.

In relation to the load-bearing capacity and exact

fit of connections, DIN 1052 requires the following

in respect of the installation of timber with exces-

sive moisture content:

• The reduction of the characteristic values to 2/3

for the load-bearing capacity for nail connec-

tions exposed to pull out stress • Deformation

through shrinkage in relation to butt joints and

contact connections to be taken into considera-

tion in the verification of serviceability

• The retightening of bolted joints

Here again, KVH®, Duobalken® and Triobalken®

offer decisive advantages over normal sawn

structural timber.

Wood preservation

Finally it should also be noted that the use of dry

timber is an important precondition for the clas-

sification of component attachments in Use Class

0 in accordance with DIN 68800-2, in order to be

able to dispense with preservative treatment.

In addition, a field study [3] demonstrated that

building components made of kiln-dried timber

used for interiors and for protected outside areas

are "resistant to insects".


8 Tenders and principles of standards

Wood

species

KVH® structural timber and Duobalken® and Triobalken® beams are made of spruce/fir as

standard. However, they can also be supplied in pine, larch and Douglas fir as well on request.

Where it is intended that the products be used within the terms of Use Class 2 as defined by

DIN 68800-3 (temporary humidification, e.g. in protected outside areas) and no preservative

treatment is to be used, the tender document must specify sapwood-free dark-colored heart-

wood of larch or Douglas fir.

S13TS/C30 KVH® structural timber and Duobalken® and Triobalken® beams are also available, on request, in

grading class S13 in accordance with DIN 4074-1 or in strength class C24. It is possible for such

higher strengths to be required because of specifications derived from statical calculations.

Wooden constructions involving KVH®, Duobalken® and Triobalken®

The German contract procedures for building works (VOB/A, Section 9) stipulate the following: "The work

required must be described clearly and in sufficient detail to ensure that all bidders understand the

description to have the same meaning and to enable them to calculate their prices with certainty and

without extensive preparatory work." You can only be certain of obtaining the correct product if the word-

ing in your tender documents is clear, complete and correct in technical terms. Given the high standard

of quality to be met by KVH®, Duobalken® and Triobalken®, careful quality controls are required during

production. It is therefore in your own interests for you to ensure that the timber you are supplied with

comes from quality supervised production sources. For an up-to-date list of supervised firms, please see

www.kvh.eu. in the internet.

Principles of standards (the latest versions of each standard of relevance for tenders)

ATV DIN 18334 18334 German VOB contract procedures for building works - Part C: General technical

specifications for building works for carpentry and timber construction works

(VOB Vergabe- und Vertragsordnung für Bauleistungen - Teil C: Allgemeine Technische Ver-

tragsbedingungen für Bauleistungen (ATV) - Zimmer- und Holzbauarbeiten)

(current version, 2006-10)

DIN 1052 Design of timber structures - General rules and rules for buildings (Entwurf, Berechnung und

Bemessung von Holzbauwerken - Allgemeine Bemessungsregeln und Bemessungsregeln für

den Hochbau) (current version, 2008-12)

DIN 4074-1 Strength grading of wood - Part 1: Sawn coniferous timber (Sortierung von Holz nach der

Tragfähigkeit - Teil 1: Nadelschnittholz) (current version, 2003-06)

DIN 68800-2 Wood preservation - Part 2: Preventive constructional measures in buildings (Holzschutz - Teil 2:

Vorbeugende bauliche Maßnahmen im Hochbau) (current version, 1996-05)

DIN 68800-3 Wood preservation - Part 3: Preventive protection of wood with wood preservatives (Holz-

schutz - Teil 3: Holzschutz; Vorbeugender chemischer Holzschutz) (current version, 1990-04)

Tender wording for the supply of construction timber made of KVH® structural timber

Item ... ... m³ Supply of KVH® Si structural timber, S10/C24

KVH® Si (for exposed areas) structural timber compliant with DIN 4074-1 S10TS (strength class C24

in accordance with DIN 1052). Moisture content: um = 15 ± 3%. Type of cutting: Split-heart.

Surface: Planed and chamfered. Dimensional stability class 2 in accordance with EN 336,

from a quality supervised production source.

Item ... ... m³ Supply of KVH® NSi structural timber, S10/C24

KVH® NSi (for non-exposed areas) structural timber compliant with DIN 4074-1 S10TS (strength

class C24 in accordance with DIN 1052). Moisture content: um = 15 ± 3%.

Type of cutting: Split-heart. Surface: Leveled and chamfered. Dimensional stability class 2 in

accordance with EN 336, from a quality supervised production source.

Tender wording for the supply of laminated beams

Item ... ... m³ Supply of Duobalken® Si laminated beams, S10/C24

Duobalken® Si (for exposed areas) laminated beams, made of two planks which are glued

together, compliant with DIN 4074-1 S10TS (strength class C24 in accordance with DIN 1052).

Moisture content: um = max. 15 ± 3%. Surface: Planed and chamfered. Dimensional stability

class 2 in accordance with EN 336, from a quality supervised production source, in accordance

with approval number Z-9.1-440.

Item ... ... m³ Supply of Triobalken® Si laminated beams, S10/C24

Triobalken® Si (for exposed areas) laminated beams, made of three planks which are glued

together, compliant with DIN 4074-1 S10TS (strength class C24 in accordance with DIN 1052).

Moisture content: um = max. 15 ± 3%. Surface: Planed and chamfered. Dimensional stability

class 2 in accordance with EN 336, from a quality supervised production source, in accordance

with approval number Z-9.1-440.

Note: Duobalken® and Triobalken® beams can also be supplied for non-exposed areas, in which case the

surface is planed and leveled.

Special requirements


Inspection mark

for KVH® structural

timber without finger-

jointing

Inspection mark

for KVH® structural tim-

ber with finger-jointing

Inspection mark

for Duobalken® beams

9 Quality assurance and marking

Section 20 of the federal state building regula-

tions in Germany and Section 17 of the German

Model Building Regulations (version 11/2002)

contain the stipulations under which construction

products may be used for the erection, alteration

and maintenance of built structures. They require

that construction products must bear either the

national mark of conformity ("Ü" mark) or the mark

of conformity required under the provisions of the

Construction Products Law or the Construction

Products Directive of the European Community

(CE mark of conformity). Building law is violated if

sawn structural timber products which do not bear

such marks are used for load-bearing structures.

Marking of KVH® structural timber

KVH® structural timber is currently still marked

with a "Ü" mark, although it should be noted that

a distinction is made in the mark between KVH®

with finger-jointing (the general case) and KVH®

without finger-jointing. The "Ü" mark provides

verification that the product conforms with the

regulations of the building authorities.

The "Ü" mark has to be included on the product

or the waybill/packaging. Alternatively it can be

applied to the product itself in the form of a text

mark. This must specify the manufacturer, the

object of the approval, the grading class and the

date of production; the "Ü" mark itself has to be

included on the waybill. Where considered desir-

able for reasons of appearance it is permissible

to dispense with the application of the mark on

the product itself in the case of KVH®-Si structural

timber for exposed areas. In this case the mark

only has to appear on the delivery note.

As from autumn 2009 the use of KVH® structural

timber without finger joints should be permissi-

ble as an alternative in Germany, also in accord-

ance with DIN EN 14081-1 and the associated

standard DIN V 20000-5. However, it is hardly likely

that non-finger-jointed KVH® structural timber

with a CE mark of conformity will be available in

any great quantities, certainly for the next few

years at least.

The members of the Überwachungsgemeinschaft

Konstruktionsvollholz e.V. monitor the quality

of their products through quality controls within

their companies (internal monitoring) and ad-

ditional monitoring by independent agencies.

This applies not just to the mandatory character-

istics required under regulations but also to the

additional requirements stipulated within the

agreement on structural timber. Only structural

timber which is monitored in this way and is

manufactured by the companies which are mem-

bers of the Überwa-

chungsgemeinschaft

Konstruktionsvollholz

e.V. is permitted to bear

the internationally pro-

tected KVH® trademark.

Marking of Duobalken® and Triobalken® beams

Duobalken® and Triobalken® beams are non-stand-

ardized products. In terms of building regulations

requirements they are regulated by product

approval number Z-9.1-440 issued by the Deutsche

Institut für Bautechnik (DIBt).

Z-9.1-440 - Duobalken® and Triobalken® beams

(laminated beams made of either two or three

boards, planks or pieces of square-sawn timber

which are glued together)

Continuous production controls by the manufac-

turer (internal monitoring) as well as monitoring

by an external agency are mandatory for these

products. Compliance with requirements is

documented by the German "Ü" mark; there is no

provision for marking with a CE mark of conform-

ity. In addition to the "Ü" mark, the description of

the object of approval (Duobalken® or Triobalken®

beams) and the grading class also have to be

specified. Where considered desirable for reasons

of appearance the timber can be marked with a

permanent text code instead of the "Ü" mark, as

long as the "Ü" mark is printed on the waybill.

Special characteristics of Duobalken® and

Triobalken® beams

The approval for Duobalken® and Triobalken®

beams allows the application of 5% higher values

for the modulus of elasticity compared to solid

timber. With a value of 11,600 N/mm2 it is pos-

sible to reduce the amount of deflection, which is

a major advantage in relation to a criterion which

is often decisive in timber construction. The mean

values of MOE and shear-modulus are therefore

the same as those for glued laminated timber

of strength class GL24 (previously BS11). All the

other strength properties are the same as those

for solid timber or KVH® structural timber.

KVH®

36 Technical Information - Issued 12/2009

Advantages of KVH® structural timber

• Dried structural timber components available in cross-sections of up to 14/26 cm

• Dimensionally stable because they are kiln-dried to 15 ± 3% and cut on a split-heart basis (free-of-heart on request)

• Two qualities available:

- planed for exposed areas (Si)

- leveled for non-exposed areas (NSi)

• Meets higher requirements than those specified in grading standard DIN 4074-1

• Suitable for structural timber in timber frame buildings and timber house construction

• Minimum tender specification work because of a clear agreement on quality

• Resistant to insects thanks to kiln drying; preservative treatment can be dispensed with

• Economical preferred cross-sections and lengths of up to 13 m available for immediate delivery from stock;

longer lengths available on request

Advantages of Duobalken® and Triobalken® beams

• Larger cross-sections of up to 24/28 cm or 10/36 cm available

• Dimensionally stable because they are kiln-dried to a maximum of 15%, cut on a split-heart basis

(free-of-heart on request) and glued

• Fewer glued joints than glued laminated timber (max. 2) and the glued joints are hardly visible

• Two qualities available:

- planed for exposed areas (Si)

- leveled for non-exposed areas (NSi)

• Greater rigidity than solid timber of the same strength class

• Suitable for voluminous or high cross-sections with high requirements in terms of appearance

• Resistant to insects thanks to kiln drying; preservative treatment can be dispensed with

• Economical preferred cross-sections and lengths of up to 13 m available for immediate delivery from stock;

longer lengths available on request

Überwachungsgemeinschaft KVHKonstruktionsvollholz e.V.Elfriede-Stremmel-Str. 6942369 Wuppertal - GermanyService telephone:Phone ++49 (0)700 - KVH DUO TRIOor ++49 (0)700 - 58 43 866 87Fax ++49 (0)202 – 978 35 79E-mail [email protected] www.kvh.de und www.kvh.eu KVH®

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