The Construction of Walls, part 2

Masonry. A masonry wall can either be solid, with a cavity or used as a skin to a timber framed wall. Masonry walls may consist of brick, block, stone or concrete block.

The masonry wall may be reinforced or unreinforced depending upon the country or area that you live in and the local building code requirements.

DPC. DPC stands for Damp-Proof Course. This stops moisture travelling through the foundations up into the walls of the building.

With a raft foundation the DPC must cover the whole foundation as the floor is in direct contact with the ground. I.e. the floor is part of the foundation. It can be bitumen soaked felt or more often nowadays an impervious plastic such as polythene.

Building Paper. In light timber framed construction this goes between the framing and the cladding. It is used to stop moisture transference and drafts. It also prevents condensation forming on the interior of the cladding, which can get into the framing and soak through the internal linings into the house.

Modern papers such as a Tyvec are in fact woven plastics and very effective. All joins should be taped to help stop drafts.

With most cladding some wind gets through gaps and holes in joints. The building paper will reduce if not stop this and by doing so maintain the insulation provided by the cavity. Building paper must be able to breath to allow water vapour to pass through it and not be trapped in the cavity.

The factors that determine what the wall will be made of.

Appearance The choice of the owner on what he or she wants the wall to look like.

Economics Local materials are often cheaper than imported materials.

Longevity The wanted duration of the buildings life. Sometimes it is unnecessary or uneconomical to build with permanent materials.

Versatility Timber framed walls/partitions are far easier to modify than concrete or masonry construction.

Security Solid masonry is far more difficult to break through than light timber frame.

Climate Differing materials will have different thermal properties. Dense material such as stone takes longer to heat up and cool down but will retain that heat or cold longer than a light timber framed wall.

Noise The denser the material (unless using specific noise control systems) the less noise / sound transference.

Generally the wall may be of combustible or non-combustible material such as timber verses brick. All materials have to (by way of building regulation) have a degree of resistance to combustion. This is called fire resistance and is measured in degrees by the building authority as to where the material may be used. The wall may have openings such as windows and doors and these should be taken into account in the context of firewall specific design. This is most common in boundary walls or walls adjacent to other properties and the designer should be aware that desired openings through the wall may or may not be permitted by building authorities.