Damp problems are very common in older houses especially in the UK which has a wet climate. Read on to find out how to identify the signs of damp and to find out what you can do to cure and prevent damp from damaging your home.
Problems with Damp
Any home which is not properly looked after has the potential for a damp problem. If the problem is not tackled the consequences can include damaged furnishings, expensive structural repairs as well as ill health.
Causes of Damp
In older houses the walls are usually solid which encourages damp but in many cases damp is encouraged due to poor maintenance. The roof, walls, floors, windows and doors and pipe work in and outside the house, are all potential causes of damp. Usually a damp patch inside the home is easily identified as being linked to a problem outside the house. A damp patch at the top of a chimney breast will indicate the probable cause is a leak through the chimney stack. A wet patch at the top of a wall might be due to a leaking gutter outside. Damp near windows and doors also offer vital clues. Sometimes though, a damp patch is not near the source of the leak on the outside. Instead the damp is coming from a distance away. The water could be finding its way along a joist, for example.
Signs and Remedies for Damp
There are many signs to look for and a variety of remedies:
- Loose flashing – Replace broken bits with adhesive flashing patch.
- Cracked chimney stack or crumbling mortar – Repair with mortar or sealant.
- Damp chimney stack – May need slating and ceiling at the top or adding ventilation bricks to increase ventilation.
- Gutters and down pipe blockages and leaks – Clear gutter and pipe and repair broken joints and cracks as necessary.
- Cracked walls – These can let in rainwater so repair with suitable filler.
- Blocked airbricks – Clear these to encourage ventilation.
- Cracked or missing tiles on the roof – Repair immediately.
- Plumbing leaks in the system, bursting tanks – Repair as necessary. Insulate pipes and tanks to prevent freezing in winter.
- Gaps between doors and frame – Fit insulation rubber or weather bar.
- Gaps between windows and frame – Clean or refit sills. Add weather bar.
- Damp patch on wall – A damp proof paint is often enough to prevent damp from spreading.
Installing a Damp Proof Course
Modern homes built in the last 60 years normally have cavity walls – two layers of bricks with a space between – which helps prevent damp. At the base of the wall a damp proof course is usually installed. This is normally a waterproof covering such as slate or a bituminous material, etc. Many older houses will have had a damp proof course injected at a later date. Damp proof courses are controversial because they are often expensive when using a contractor and if not properly implemented or maintained they are not brilliantly effective, leaving you out of pocket. Rising damp due to a faulty or deteriorated damp proof course can cause considerable damage to your joists and walls. And while a faulty damp proof course cannot be repaired the good news is that it can be replaced fairly easily. It is really worth considering doing this yourself as it will save you money and it is not that difficult to do.
Probably the easiest method is to use a chemical/silicon injection:
- You can hire all the equipment you need for pumping in the liquid.
- You simply drill 10mm holes, downward sloping, about 150mm below floor level.
- The holes should be angled so they slope to the centre of the wall.
- You may need to drill holes from both sides if the wall is thick
- The brickwork around the holes sweats when there is enough chemical injected into it.
- Then you seal the holes with mortar or plastic plugs. If you don’t, the damp course will be become ineffective.
Prevention and Monitoring
Often the best cure for damp is plenty of ventilation. A few preventative measures or early intervention can also work wonders in keeping your home dry.
- Get up in the loft and check under your roof for leaks.
- Check your chimney stacks and around them.
- Check insulation on doors and windows.
- Open windows and allow ventilation around your home when weather conditions allow.
- Keep airbricks clear to ensure good ventilation.
- Maintain and clear gutters.
- Check outside walls at ground level and check damp proof courses are operating successfully.
- Maintain external and internal paintwork – use plenty of coats and special damp proof paint if necessary.
Remember, the very best cure for damp is often simple – ventilation. A well ventilated property will do a lot of work towards preventing damp. Also, remember that damp may occur after very heavy rain when older brick work becomes sodden. It may then rectify itself when normal weather returns. So don’t rush into expensive repairs unless you are sure they are absolutely necessary. Often the remedy is quite simple. If in doubt consult a trusted professional.