Ensuring that your home is protected from damp, fungus and insects can be costly but will save you money in the long run, says Anna Bowden
Damp and rot are commonly encountered problems in properties of all ages, and can occur for a variety of reasons. The most easily remedied occurrence is from a water leak – for example a burst water pipe or leaking guttering – but the solution is unfortunately not always that easy. Controlling damp is a job for the professionals, which, sadly, means forking out, but an ounce of prevention is worth a pound of cure. So check your home regularly for signs of leaking water and rot, as it could save you time and a lot of money in the long run.
Rising damp
This occurs when a damp proof course (damp course) is absent or has deteriorated, allowing water from the ground to seep up through the floor of the building.
The source of this is to be found in the soil, as water is raised through the brickwork by capillary action. Such water is not pure - nitrates and chlorides are brought up as salt, contaminating the brickwork, plaster and decorations. In turn these salts bring moisture from the atmosphere into the plaster.
Dry rot
Dry rot can affect properties of all ages and is caused by a high moisture level often found in areas suffering from rising damp. Severely affected timbers can be remedied without widespread damage to the structure. Dry rot is caused by serpula fungus, which is white and can leave wood a dry dust held together only by its strands. It is particularly dangerous as the fungus can travel across or through masonry to find a fresh wood supply. The first sign of dry rot is often a rust-coloured dust produced by spores. The treatment is similar to that for damp rot, though it can be much more difficult to eradicate.
Wet rot
Usually caused by a fungus from the coniophora puteana family, damp rot can appear white or brown and attacks the surface or interior of wood that comes into contact with moisture. Treatments involve drying out the wood and can include chemicals.
Woodworm
Woodworm is the most commonly used name for all wood-boring insects, including the common furniture beetle, the death watch beetle and the house longhorn beetle. The common furniture beetle, usually brought into the house with old furniture and packing cases, attacks the sapwood of softwood timber. The death watch beetle mainly occupies old buildings with a history of decay. Roof timbers are particularly susceptible. The house longhorn beetle is located in the south of England, mainly north west Surrey. As it also attacks the sapwood of softwood timber, differential identification is essential to treatment.
Penetrating damp
This occurs when water works its way through an exterior wall or roof, and is more common in older homes where walls are solid. The symptoms of penetrating damp are usually seen only in wet weather, and it is generally easy to pinpoint the source of the problem.
Areas to watch
Damp proof course
Sometimes referred to as a damp course or dpc, this is a layer of waterproof material like polyurethane at the base of a building. It acts as a barrier to water seeping up from ground level and if missing or damaged can leave a building at risk
Pointing
Mortar or cement between bricks is sometimes referred to as pointing. Damaged or missing mortar can allow water to seep into the brickwork
Flashing
A strip, usually lead or zinc, which seals the junction of roof sections. Cracks or damage to the flashing can allow water into a building