What are the 3 most common causes of a defect?
- Ground movement
- Water ingress
- Defective / non performance part of the buildings
What is subsidence?
The vertical downward movement of a building caused by the ground beneath the property sinking.
What are the signs of subsidence?
- Diagonal cracks that are wider than 3mm and located next to doors or windows
- They are usually narrow at the bottom and wider at the top
What is heave?
Heave is the opposite of subsidence and is where soil beneath the house becomes saturated with water, which causes the soil to expand and pushes the foundations up.
What are the signs of heave?
- Lifting of paths and patios in the surrounding area
2. Vertical cracking to brickwork
What is settlement?
Where the ground below the property becomes compacted, usually within the first 10 years of being built.
What are the 3 common causes damp?
- Water ingress
- No DPC
- Poor ventilation
What are the different types of damp?
- Penetrating damp
- Rising damp
- Condensation
What is penetrating damp?
Where excess water penetrates the external brickwork and transfers to the internal walls.
What are the 5 common causes of penetrating damp?
- Damaged exterior brickwork
- Roof leak
- Blocked gutters
- Blocked air bricks
- Burst pipes
What are the signs of penetrating damp?
- Damp patches
- Spalling of plaster
- Black mould
What is rising damp?
Rising groundwater through masonry by capillary action - usually as a result of failed DPC.
What are the signs of rising damp?
- Damp patches which start at the wall and move vertically up to 1 - 1.5m.
- Skirting boards that are rotting
- Tide marks of salts
What is condensation?
When water vapour hits cold surfaces like windows or walls.
What is condensation caused by?
Excess moisture in the air from everyday activities coupled with poor ventilation.
What are the signs of condensation?
- Streaming water on cold surfaces
2. Black mould
Why is damp a problem?
It can lead to structural problems and also wet rot and dry rot.
What are the 4 common defects in office buildings?
- Structural movement
- Damaged cladding
- Damp penetration
- Water damage from defective air con units / pipes
What are the 4 common defects on industrial buildings?
- Roof leaks around roof lights
- Damaged cladding
- Blocked gutters
- Cut edge corrosion
What is spalling?
Spalling is where the surface of brickwork or plaster has started to crumble.
What are the 4 common defects on period office / shop buildings?
- Structural movement
- Damp penetration
- Rising damp
- Tile slippage
