Damp Proofing specialists - what you need to know
What is damp proofing?
Damp proofing protects your walls, flooring and ceilings from moisture or water intrusion. If damp gets into your home, it can cause unpleasant stains, and structural damage in more severe cases. You might hear terms like rising damp, penetrating damp or simply condensation mentioned – they all involve degrees of moisture penetration into a building.
Damp proof coursing essentially involves creating a waterproof layer, and the exact approach or materials used will depend on where the treatment is being applied. The first step to installing damp proofing is to identify the wall, ceiling or floor where the problem is, before drying it out to remove all residual moisture. Depending on the type of damp and the location, a damp proof membrane, injectable silicone solution or painted layer (essentially a barrier) can then be applied to keep moisture or water out.
Older buildings or those with specialist construction (such as timber-framed homes) will usually need more attention, but every structure will require some form of damp proofing. These treatments will help to prevent flaking plaster, stained walls or more serious structural degradation in the longer term. By correctly applying damp proofing, you can also preserve timber by blocking moisture and preventing outbreaks of dry and wet rot.
Cost of damp proofing
There are a number of causes for damp issues, and often one of the trickiest pieces in the puzzle is finding out which location (or locations) water or moisture is entering the building from. As the reasons can be wide-ranging, the costs to resolve damp issues can likewise vary significantly.
Excavating a soil layer to help a damp proof course do its job can be one solution. Fees for this type of work typically range from £200 up to £2,000 (if an existing garden, driveway or patio needs to be removed and then reinstalled).
For buildings that don’t have any existing damp proof treatment in place (or those where the current coursing is damaged or defective), installing a new membrane or injecting a silicone solution can cost from £300 (for a single wall) up to many thousands of pounds for an entire home.
How to damp proof your home
The damp proofing treatment your tradesperson recommends will depend on the cause of damp in your home. A minor damp problem may be simple enough to remedy – fixing a broken roof tile, replacing guttering or just applying a specialist stain blocking paint.
But more intensive damp proofing will require your tradesperson to first locate the leak or other issue that’s creating the problem, so the appropriate solution can be installed. In situations where the ground level has risen above the damp proof coursing, soil excavations can solve the issue. Here it may be necessary to bring ground levels down to 15cm below the damp proofing.
Installing a damp proof membrane to a floor or wall is another common method of protecting against potentially damaging moisture entering your home. Damp proof membranes are typically polythene or plastic sheeting which prevent warm air meeting cold air inside your home, causing condensation, as well as blocking out rising damp from entering.
Damp proof membranes must be fitted underneath insulation material. It’s also important to make sure the membrane is carefully sealed and all joints and staple holes are covered. Where membranes aren’t possible, or cost effective, walls can also be damp proofed by drilling holes and then injecting a special silicone solution.
What causes damp?
One of the main reasons for damp in a home is the lack of a damp proofing course or a broken membrane, leaving you without protection from moisture. However, damp can arrive in your home for a number of reasons.
- Plumbing – leaking internal pipes, even if it’s just small drops, can create wet patches over time. If the moisture doesn’t dry or drain away, eventually the affected wall, ceiling or floor will become saturated and damp will spread to surrounding areas.
- Leaking gutters or downpipes – water spilling out of guttering, or seeping through cracks in downpipes might seem innocent enough, but splatter onto window sills or trickling water down onto exterior brickwork can cause water to accumulate and penetrate into internal walls or ceilings.
- Holes in roofing or cracked chimney stacks – it might sound obvious, but it can be easily overlooked: damp on a ceiling or internal wall is often the sign of a broken roof tile or a cracked chimney stack. Rain will find its way through the tightest of spaces, and if the moisture doesn’t dry out it can cause a damp problem that will need addressing.
- Moss and vegetation – moss on roofing and climbing plants on walls can soak up water to prevent surfaces from drying, as well as forcing water away from intended drainage points (like guttering and downpipes). Keep your roof and your walls clean and you’ll reduce your chance of encountering damp issues.
The qualifications your damp proofing specialist needs
Unlike some of the more common trades, damp proofing experts won’t necessarily need to hold a qualification or formal accreditation. The most valuable quality for a damp proofing specialist will be experience – for two reasons.
Firstly, the more experience they have, the more knowledge they can call upon to not only find the cause of your damp problem, but also the most effective way to resolve it. And secondly, it should mean they are able to provide a number of references from previous customers to prove their capability.
Insurance for damp proofing
Damp proofing treatments may require extensive work to be conducted within your home, so it’s wise (even before an initial inspection of the damp issue takes place) to make sure whoever you hire has full public liability insurance.
It’s also worth investigating whether you may be eligible for grants towards your damp proofing work. For some properties in certain areas, government contributions may be available for work that improves a building’s energy efficiency.
Questions you should ask your damp proofing specialist
- Are they specialists in damp proofing, rather than general building?
- Can they provide examples of previous damp issues they have solved that are similar to your scenario?
- Do they provide a warranty on their damp proofing work?
- For the damp proofing of walls, would they recommend silicone injection or installing a membrane (and why)?