input W = Load per square foot 150 psf

input 1330 Allowable

input Cd 1 factor

input Cf 1.1 factor

input C* 1 factor

input C** 1 factor

Calculated 1463 corrected

input bredth of joist 4 inch

input depth of joist 8 inch

input Modulus of Elasticity for Wood Type 1,200,000 choose E from from literature values for type of wood species

input Spacing "s" of joist 15Calculated Tributery transformed W Load to "q" per LF "q" 187.50input L = span of joist 12Calculated M = Bending Modulus (wL^2)/8 3375.00Calculated Section Modulus - Sx = M*(12)/Fb' 27.68Calculated Moment of Inerta Moi (bd^2)/6 42.67Calculated Delta between Sx and Moi 0.649

input Choose Max Deflection (360, 180, Etc) Value X 450Calculated 0.320Calculated 0.003Calculated Ratio 0.009

Calculated Max allowable Load 20227

input Literature Shear Value for wood species Fv 95Calculated 5.542Calculated Shear pass if shear value less than literture value 0.058Calculated 1.48Calculated section of chosen timber above 42.7Calculated shosen section OK if ratio less than 1 0.035

In general, span and lebut here is scant inforThis gives a more direc

The point load is placeit can be placed in bewedistributed to adjacent joist. If the direct load is safe, then the other locationsare safe also. Spacing Fb is corrected with C factors to give the useable Fb'. Obtain from literatureThe C factors are range

JOIST SPAN AND SPACING - DISTRIBUTED LOAD Non_FLAT USE Non Incised By Gugi

FB from published tables

Fb' = Cd*Cf*…C*FB

Allowable deflection L/X from value chosen aboveDesign Deflection -((5*w*(L^3))/((384*E*(b*d^3)/12))

Design Shear V={(3/2)V}/(bf*df) in PSI

Section Required based on shear = (V*(bf*df))/Fv

E or elasticity modulus is used for calculationg deflection. Varios values of L/Xcan be put in for measuring deflection valaues.Max alalowble load per joist is calculatedThe designer can play with joist leagth and breadth and depth values to arrive atsuitable leangth and section of the joist. Compare with literatureallowable L/x valaues to see if the value presented here conforms with it.If not, modifications to load, L, breadth, depth and timber structural types canbe made.

Draft- to be updated

Here, the spacing calculations is based on the fact that as the joist spacing or separation gets larger, the tributary between the joists gets larger. The tributary area is geometrically be halfway from one joist to halfway to another joist. As the joist gets separated or get closer, the area of the joist tributary changes. For example, if the joist separation doubles, the area also tributary area acting on the joist increases and it translated into more "q" of line load on the joist which is taken as a beam.

Input various values of depth and bredth of timber, Leangth of Joists, and Seperation or sapcing "s" of joists.

choose E from from literature values for type of wood species

inches

((lb/ft^2 which is "w "times ft (spacing)= lbs/ft

ft

this should be smaller than moment of inertia below

Ok if < 1.0

input

tributery area of one joist = sOk if < 1.0

lbs joist Tributery looking parellel or axial direction to joists

psi horizontal shear

Incised b and d values of wood; ( ie, 2 by 12 is 1.5 by 11.25)

Ok if < 1.0

Ok if < 1.0

The loading on a joist increases or decreases pending on the loaddistribution around the joist. As spacing increases, more loading

that Sx is less than the Moment of Inertia

Non_FLAT USE Non Incised By Gugi

is placed on a joist. One can iteratively use various L and s to see

Wood Values given in tab

Here, the spacing calculations is based on the fact that as the joist spacing or separation gets larger, the tributary between the joists gets larger. The tributary area is geometrically be halfway from one joist to halfway to another joist. As the joist gets separated or get closer, the area of the joist tributary changes. For example, if the joist separation doubles, the area also tributary area acting on the joist increases and it translated into more "q" of line load on the joist which is taken as a beam.

Input various values of depth and bredth of timber, Leangth of Joists, and Seperation or sapcing "s" of joists.

input point Loadinput FB from published tables 1900input Cd 1input Cf 1.1input C* 1input C** 1

Calculated 2090input bredth of joist 4input depth of joist 10input Modulus of Elasticity for Wood Type 1000000

X Spacing "s" joist inchesinput L = length of joist

(PL^2)/4Section Modulus - Sx = M*(12)/Fb'Moment of Inerta Moi (bd^2)/6Delta between Sx and Moi

input Choose Max Deflection (360, 180, Etc) XL/X calculatedMax allowable Load lbs

TO BE UPDATED

In general, span and length tables are abundant for general non specialist userbut here is scant information as to who the spans and spacing are derived.This gives a more direct approach to calculate spans and spacing

The point load is placed in the center of the joist for maximum load and stressit can be placed in beween the joists, however, then the load is partiallydistributed to adjacent joist. If the direct load is safe, then the other locationsare safe also. Spacing is not considered here.Fb is corrected with C factors to give the useable Fb'. Obtain from literatureThe C factors are ranges based in literature for various conditionsE or elasticity modulus is used for calculationg deflection. Varios values of L/Xcan be put in for measuring deflection valaues.Max alalowble load per joist is calculatedThe designer can play with joist leagth and breadth and depth values to arrive atsuitable leangth and section of the joist. Compare with literatureallowable L/x valaues to see if the value presented here conforms with it.

JOIST SPAN AND SPACING - POINT LOAD non incised non flat use By Gugi

Fb' = Cd*Cf*…C*FB

Mx = Bending Modulus

If not, modifications to load, L, breadth, depth and timber structural types canbe made.

Draft- to be updated300.00 lbs

This information can be obtained for wood species and dimensions in literature for various speciesfactorfactorfactorfactor

correctedinchinch

from literatureNA12

10,800 62 this should be smaller than momenbelow67

0.930 OK if value<1.0180 code =

0.067 OK if value<1.082305

360, etc)

non incised non flat use By Gugi

This information can be obtained for wood species and dimensions in literature for various species

Example allowable

L

Understanding Wood: A Craftman's Guide to Wood Technology google books By R. Bruce Hoadley

TO BE UPDATED

Tree Species

10^6 psi psi psiU. S. Hardwoods

Alder, Red 1.38 440 1,080

Ash, Black 1.6 760 1,570

Ash, Blue 1.4 1,420 2,030

Ash, Green 1.66 1,310 1,910

Ash, Oregon 1.36 1,250 1,790

Ash, White 1.74 1,160 1,910

Aspen, Bigtooth 1.43 450 1,080

Aspen, Quaking 1.18 370 850

Basswood 1.46 370 990

Beech, American 1.72 1,010 2,010

Birch, Paper 1.59 600 1,210

Birch, Sweet 2.17 1,080 2,240

Birch, Yellow 2.01 970 1,880

Butternut 1.18 460 1,170

Cherry, Black 1.49 690 1,700

Chestnut, American 1.23 620 1,080

Cottonwood, Balsam Poplar 1.1 300 790

Cottonwood, Black 1.27 300 1,040

Elm, Eastern 1.37 380 930

Elm, American 1.34 690 1,510

Elm, Rock 1.54 1,230 1,920

Elm, Slippery 1.49 820 1,630

Hackberry 1.19 890 1,590

Hickory, Bitternut 1.79 1,680 -

Hickory, Nutmeg 1.7 1,570 -

Hickory, Pecan 1.73 1,720 2,080

Hickory, Water 2.02 1,550 -

Hickory, Mockernut 2.22 1,730 1,740

Hickory, Pignut 2.26 1,980 2,150

Hickory, Shagbark 2.16 1,760 2,430

Hickory, Shellbark 1.89 1,800 2,110

Static Bending

Modulus of Elasticity (E)

Compress. Perpen.  to Grain, Fiber

Stress at Prop. Limit

Shear Parallel to Grain, Max

Shear Strength

Honeylocust 1.63 1,840 2,250

Locust, Black 2.05 1,830 2,480

Magnolia,Cucumbertree 1.82 570 1,340

Magnolia, Southern 1.4 860 1,530

Maple, Bigleaf 1.45 750 1,730

Maple, Black 1.62 1,020 1,820

Maple, Red 1.64 1,000 1,850

Maple, Silver 1.14 740 1,480

Maple, Sugar 1.83 1,470 2,330

Oak, Black 1.64 930 1,910

Oak, Cherrybark 2.28 1,250 2,000

Oak, Laurel 1.69 1,060 1,830

Oak, Northern Red 1.82 1,010 1,780

Oak, Pin 1.73 1,020 2,080

Oak, Scarlet 1.91 1,120 1,890

Oak, Southern Red 1.49 870 1,390

Oak, Water 2.02 1,020 2,020

Oak, Willow 1.9 1,130 1,650

Oak, Bur 1.03 1,200 1,820

Oak, Chestnut 1.59 840 1,490

Oak, Live 1.98 2,840 2,660

Oak, Overcup 1.42 810 2,000

Oak, Post 1.51 1,430 1,840

Oak, Swamp Chestnut 1.77 1,110 1,990

Oak, Swamp White 2.05 1,190 2,000

Oak, White 1.78 1,070 2,000

Sassafras 1.12 850 1,240

Sweetgum 1.64 620 1,600

Sycamore, American 1.42 700 1,470

Tupelo, Black 1.2 930 1,340

Tupelo, Water 1.26 870 1,590

Walnut, Black 1.68 1,010 1,370

Willow, Black 1.01 430 1,250

Yellow-poplar 1.58 500 1,190

U. S. Softwoods

Baldcypress 1.44 730 1,000

Cedar, Alaska 1.42 620 1,130

Cedar, Atlantic White 0.93 410 800

Cedar, Eastern Redcedar 0.88 920 -

Cedar, Incense 1.04 590 880

Cedar, Northern White 0.8 310 850

Cedar, Port-Orford 1.7 720 1,370

Cedar, Western Redcedar 1.11 460 990

Douglas-fir, Coast 1.95 800 1,130

Douglas-fir, Interior West 1.83 760 1,290

Douglas-fir, Interior North 1.79 770 1,400

Douglas-fir, Interior South 1.49 740 1,510

Fir, Balsam 1.45 404 944

Fir, California Red 1.5 610 1,040

Fir, Grand 1.57 500 900

Fir, Noble 1.72 520 1,050

Fir, Pacific silver 1.76 450 1,220

Fir, Subalpine 1.29 390 1,070

Fir, White 1.5 530 1,100

Hemlock, Eastern 1.2 650 1,060

Hemlock, Mountain 1.33 860 1,540

Hemlock, Western 1.63 550 1,290

Larch, western 1.87 930 1,360

Pine, Eastern white 1.24 440 900

Pine, Jack 1.35 580 1,170

Pine, Loblolly 1.79 790 1,390

Pine, Lodgepole 1.34 610 880

Pine, Longleaf 1.98 960 1,510

Pine, Pitch 1.43 820 1,360

Pine, Pond 1.75 910 1,380

Pine, Ponderosa 1.29 580 1,130

Pine, Red 1.63 600 1,210

Pine, Sand 1.41 836 -

Pine, Shortleaf 1.75 820 1,390

Pine, Slash 1.98 1,020 1,680

Pine, Spruce 1.23 730 1,490

Pine, Sugar 1.19 500 1,130

Pine, Virginia 1.52 910 1,350

Pine, Western white 1.46 470 1,040

Redwood, Old-growth 1.34 700 940

Redwood, Young-growth 1.1 520 1,110

Spruce, Black 1.61 550 1,230

Spruce, Engelmann 1.3 410 1,200

Spruce, Red 1.61 550 1,290

Spruce, Sitka 1.57 580 1,150

Spruce, White 1.43 430 970

Tamarack 1.64 800 1,280