Damp, mould and condensation
Types of damp
Rising damp
Rising dampness is caused by moisture rising from the ground into the home. The moisture gets through or around a defective damp proof course (DPC) or passes through the natural brickwork if the property was built without a DPC.
A DPC is a horizontal layer of waterproof material put in the walls of a building just above ground level. It stops moisture rising through the walls. Rising damp will only affect basements and ground floor rooms. It will normally rise no more than 36 inches above ground level (900mm) and usually leaves a 'tide mark' low down on the wall. You may also notice white salts on the affected areas.
Rising damp will be present all year round but is more noticeable in winter. If left untreated it may cause wall plaster to crumble and paper to lift in the affected area.
Check to see that material's such as soil or building materials, have not been left against the outside of walls as this may allow the dampness to go through/around (bridge) the DPC and cause dampness in the wall. Ideally the DPC will be a minimum of 6 inches (150mm) above ground level.
If the dampness has got around the DPC, try removing the materials as this will allow the walls to dry out. If that doesn't work, a damp proofing specialist may need to be brought in to fix the problem. Tenants should report any suspected Rising Dampness to us following the Report a Repair procedure.
Mould will rarely be seen where there is rising damp (and then only in the early stages). This is because rising dampness carries with it salts that prevent the growth of mould.
Damp patches (penetrating damp)
This type of dampness will only be found on external walls or, in the case of roof leaks, on ceilings.
It only appears because of a defect in the structure of the home, such as missing pointing to the brickwork, missing roof tiles, loose flashing or leaking gutters. These defects then allow rainwater to pass from the outside to the inner surfaces. Penetrating dampness is more noticeable after a period of rainfall and will normally appear as a 'damp-patch' which looks and feels damp to the touch. "Tide marks" will be left, even in periods of dry weather.
Mould may be seen on areas of penetrating dampness but not in all cases as the dampness can contain salts picked up when passing through the wall, which may prevent the growth of mould.
Report a repair
If you have this kind of damp in your home, please log a repair with us.
Leaks from water and waste pipes, especially in bathrooms and kitchens, can cause damp.
If leaks are not repaired, rot may appear in wooden joists and floorboards leading to a risk of collapse in severe cases.
Mould and even fungi may be seen with this type of dampness if the defects are not fixed.
Leaks should be fixed as soon as possible. Tenants should contact the Repairs service immediately by following the Report a Repair procedure: