wall structures

After the foundations have been completed the walls are set out and construction commences.

Walls

Walls can be classified in a number of ways:-SolidCavityInternalExternalLoad bearing or Non load bearing

Load bearing – supporting roofs, floors etc.Non load bearing – Dividing spaces

Main functions of walls

1. Strength

2. Stability

3. Weather exclusion

4. Thermal Insulation

5. Sound Insulation

6. Durability

7. Fire resistance

8. Appearance

Part of a cavity wall with the internal skin removed to expose the Insulation

Bonding of Brickwork / Blockwork

Bonding of brickwork is the

arrangement of brickwork in a wall,

column or pier which will give maximum

overlap and no continuous vertical

joints. The purpose of bonding is to:-

1. Obtain maximum strength whilst distributing the loads carried by the walls.

2. Ensure lateral stability and resistance to side thrusts.

3. Create an acceptable appearance.

LOAD

Possible settlement

Unbonded walls – Comparatively weak and liable to fail under load or lateral thrust.

Bonding of Brickwork / Blockwork

• Bonded wall – load is distributed over the whole wall and has greater resistance to side thrust.

Standard brick sizes Length + one mortar joint =225mm

Width + one mortar joint =112.5mm

Height + one mortar joint =75mm

Mortar joint thickness = 10mm

LOAD

SPREAD OF LOAD

Stretcher Bond

This is the simplest and most widely used bond. It is used for half brick walls and cavity walls. The bricks must lap over each other in successive courses in a fashion similar to the one shown below.

Half lapped

Formation of a corner in stretcher bond

½ bat to form stopped end

Racking-back

Wall tie

Quoin

Cavity

D.P.C.

Horizontal mortar joint

Perpendicular mortar joint

Return corner of a cavity wall in stretcher bond including wall ties and DPC

Wall Ties

There are a large variety of different types of wall ties, but they all have two basic requirements of:-

(a) Tieing the outer and inner leaf of the cavity wall together.

(b) Prevent moisture passing from the outer to the inner skin of brickwork.

Most wall ties are currently

made from stainless-steel or

nylon.

Stainless-steel wire wall tie with plastic disc to hold sheet insulation in place.

Spacing of wall ties

Mortar droppings must not be allowed to accumulate on wall ties because this would form a bridge for water to pass from the outer to inner leaf.

The cavity should start

150mm below the lowest

damp proof course. In

facing brickwork every

4th vertical joint is left out

at the base of the cavity

to allow any build-up of

moisture at the base of

the cavity to escape.

Types of pointing

Curved Recessed Struck or weathered

There are several types of pointing which can be used with facing brick, Curved recessed or ( pole jointed as it is commonly called in N. Ireland) is the most popular.

Cavity walls in block construction

A cavity wall consists of two ½brick thick leaves with a cavitybetween them. The outer leaf inconjunction with the cavity actsas a barrier to moisture. TheInner leaf supports most of the loadfrom floors and the roof. If heavierloads than usual have to besupported the inner leaf can be builtone brick thick or more. There is noneed to increase the thickness of theouter leaf.

Outer leaf facing brick or block and render.

D.P.C.

Rain

Section through a Cavity Wall

Wall tie

The two leaves of the wall must be tied together with Stainless-steel cavity wall ties.

Cavity walls in brick construction with insulation

• This wall is similar in construction to the first cavity wall, the only exception being the inclusion of insulation.

• Wall ties are manufactured from stainless steel.

60mm thick insulation

Plaster

Vertical DPC at window and door jambs

Insulation

Timber stud walls

Stud partitions are still extensively used for internal walls of domestic buildings.

These are non load bearing internal dividing walls which are easy to construct, lightweight, adaptable and can be clad and filled with various materials to give different finishes and properties.

100 x 50 timber studs

Door opening

Timber stud walls

General construction consists of 100 x 50mm or 100 x 75mm sole plate and head plate. Vertical members or studs made from 100 x 38mm or 100 x 50mm members are nailed in between at 400mm centres.

The spacing is to suit the plasterboard or other cladding material.

Nogging or bridging pieces are inserted between the studs to stiffen the partition.

The timber frame is then covered with plasterboard on both sides and finished with a 3 to 5mm coat of plaster.

100 x 50mm stud

Architrave

Planted door stop

100 x 50mm stud

Door

Plaster Board

Section A A

Timber stud walls

A A

100 x 50mm sole plate

Ceiling joist

Door

openingPlaster board

100 x 50mm studs at 400c/sFloor joist

100 x 50mm head plate