The external brick walls of a house are typically of a cavity wall construction, of either ‘double brick’ type (comprising both external and internal brickwork skins, with a cavity in between and connected to each other with metal ties) of ‘brick veneer’ type (with an external brickwork skin, internal plasterboard sheeting on timber framework and a cavity in between). The bricks are basically pasted to each other with mortar.
However, as brickwork is porous and absorbs moisture, the cavity arrangement helps prevent moisture penetrating into the house, by allowing water to drain back outside, via weep holes. For further weatherproofing protection, a damp proof course (i.e. a layer of impervious material) is typically installed in the brickwork, near ground level, to prevent moisture transfer problems, such as rising damp.
Lintel bars, typically made of either steel or concrete, are usually installed directly above the windows and doors, to support the brickwork structure above.
TYPICAL PROBLEMS
- Cracks in the mortar (particularly for the lime type mortar that was typically used up to the 1950’s) and the bricks, indicating potential structural failure of the brickwork
- Corrosion of the metal ties between the brickwork, leading to reduced structural support and stability of the brickwork, as well as leading to cracks
- Corrosion of metal lintel bars, leading to reduced support of the brickwork above, which may cause cracking and sagging of the brickwork
- Excessive moisture build-up within the brickwork cavity wall, leading to problems such as rising damp, water ingress and mould, due to various reasons, such as failure of the damp proof course (including the slate type, that was often used up to the 1950’s) or insufficient drainage or weatherproofing
- Formation and build-up of salts, efflorescence, grime, mould and mildew
EXAMPLES OF OUR SOLUTIONS
- Rake out the existing soft lime mortar and replace with cement
- Remove and re-build damaged unstable brickwork
- Install new stainless steel type wall ties
- Remove and replace the corroded lintel bars and replace with new galvanised bars
- Remove damp proofing and replace with new damp-proof course. Then re-render, plaster and waterproof the walls
- Brick cleaning to remove all salts, efflorescence and grime