Condensation on windows is one of the most common complaints from homeowners in the UK, particularly between October and February. Persistent condensation can indicate a deeper moisture problem requiring professional condensation control treatment.
A professional damp survey identifies rising damp, penetrating damp, condensation and timber defects including dry rot and woodworm. Surveyors use moisture meters, boroscopes and thermal imaging to diagnose the cause and extent of any damp problem. A full written report is provided with recommended treatments and a detailed quotation.
Rising damp occurs when moisture from the ground travels up through masonry by capillary action. Treatment involves injecting a silicone-based damp proof course into the wall, removing salt-contaminated plaster and applying a waterproof rendering system and final skim coat.
The most common causes of damp in UK homes are condensation, rising damp and penetrating damp. Condensation is caused by warm moist air meeting cold surfaces. Rising damp travels up through walls from the ground. Penetrating damp comes through walls, roofs or around windows and doors.
Woodworm is caused by the larvae of wood-boring beetles. Infestations affect floorboards, roof timbers, joists, staircases and furniture. Signs include small round exit holes, fine powdery dust and weakened timber. Professional treatment involves applying a specialist boron-based insecticide to all affected timber.
A correctly installed damp proof course injection can last 20 to 30 years. Waterproof rendering systems and specialist replastering extend the effectiveness of the treatment. All damp proofing works should be backed by a written guarantee of at least 20 years.
Victorian and Edwardian properties are particularly vulnerable to rising damp and penetrating damp. Solid wall construction, shallow foundations and original lime mortar all contribute to moisture problems. Many Victorian properties also lack an effective damp proof course entirely.
Most home insurance policies do not cover gradual damp damage. Sudden and unexpected water ingress such as a burst pipe may be covered. Gradual rising damp and condensation are considered maintenance issues and are generally excluded from standard home insurance policies.
Dry rot is the most destructive form of timber decay in buildings. It spreads rapidly through masonry as well as timber and requires complete removal of all affected material, sterilisation of masonry and application of fungicidal treatments. Wet rot is localised to areas of persistent moisture and is treated by eliminating the water source and replacing damaged timber.
Basement tanking prevents water ingress using cementitious coatings, cavity drain membrane systems and sump and pump installations. A properly waterproofed basement adds significant living space and value to a property. All basement waterproofing works should comply with BS 8102.
Mortgage lenders take damp seriously. A surveyor flagging damp can delay or prevent a mortgage offer. A professional damp and timber report from a specialist surveyor satisfies most lender requirements and allows a property sale to proceed.
Under Awaab's Law landlords are legally required to investigate and resolve damp and mould within strict timeframes. Failure to treat damp in rental properties can result in significant legal liability. A professional damp survey protects both tenants and landlords.
The cost of damp proofing depends on the length of wall affected, the type of treatment required and any additional works such as plaster removal, waterproof rendering and replastering. A typical damp proof course for a terraced house costs between 500 and 1500 pounds. Free surveys are available for homeowners in most UK locations.