Damp is the presence of unwanted water or moisture in a building which, if it goes untreated, can cause structural damage. Damp is a major problem in the UK – creating cold and unhealthy living conditions in tens of thousands of homes.
Prevalent damp can have health implications, so if you think you may have a damp problem in your house it is important you get a surveyor to investigate and suggest the next steps to take.
The Types of Damp
Rising Damp
Causes - water from the ground moving upwards through the brickwork in the wall of a property
Identification - a ‘tide mark’ on the affected wall, damaged skirting boards and floorboards, crumbling plaster and peeling wallpaper
Rising damp can often be misdiagnosed, so ensure that you are getting independent advice from an expert damp surveyor.
Penetrating Damp (Rain Penetration)
Causes - water leaking through the walls, usually through cracks in the masonry
Identification - damp patches on walls, floors and ceilings
Penetrating damp most commonly occurs in older buildings with solid walls.
Condensation
Causes - moist water vapour condensing on walls
Identification - water droplets on walls, damaged plaster and paint and decaying window frames
Damp caused by condensation is the most common type of damp occurring in homes and in the UK it is particularly a problem between October and March – ‘The Condensation Season’.
Health Risks
The most common health complaints triggered by damp are asthma and other respiratory problems, which is due to the poor indoor air quality and the emission and subsequent inhalation of the mould spores damp causes. The mould can also cause infections and immunological illnesses.
The dampness provides a thriving environment for bacteria to multiply, and with bacteria being a source for the transmission of disease this can cause health risks.
Damage to Property
The damage caused by damp is more than just aesthetic. It can lead to the structural deterioration of plaster and brickwork, rotting of timber frames and the rusting of steel and iron fasteners.
If it’s left untreated the damage can be costly to repair and due to the nature of the damage caused by damp, it is likely that replastering and redecoration will be needed – a further expense.
Treatment
Each type of damp has a different treatment to control the problem. To diagnose which kind of damp is affecting your home a damp survey will need to be completed. Inappropriate damp treatment can be both expensive and potentially cause further damage to buildings, so it’s important to ensure you’re getting expert advice from a professional damp surveyor.
How to know if you need a Damp survey
If you’re buying a property be sure to get a Surveyor to carry out a building survey to make you aware if there is a damp problem that would need further investigation from an industry specialist. This will give you an opportunity to reopen price negotiations with the seller or possibly reconsider your purchase.
The kind of survey you get will depend on the age and type of the property, so make sure to look up what type of survey you need.
How does a damp survey work?
While a general property survey will identify a damp problem, your surveyor will then suggest you get a damp survey, to determine the full extent of the damp and the appropriate method of treatment .
An approved damp surveyor should be CSTDB (Certificated Surveyor of Timber & Dampness in Buildings) qualified, and have a CRDS (Certificate in Remedial Damp Surveying) or a CSRT (Certificate in Remedial Treatment), so make sure you don’t use an under-qualified or under insured trader.
The damp surveyor will use specialised tools such as a damp meter to inspect the property and determine the kind of damp present as well as what is causing it. After their survey they will send you a report detailing all their findings and what needs to be done to the property to fix the issue.
How much does a damp survey cost?
Much like any building survey, a damp survey does not have a fixed price and will vary depending on the size and location of the property. Typically a damp survey from a qualified surveyor will cost between £200-£600.
Your building surveyor may recommend someone to carry out the survey, but as always we recommend comparing other surveyors to find your best option.
Damp can cause serious damage, to both your property and your health, so if you have any concerns about damp in your home, get an independent surveyor to advise you on whether you need a damp survey.
Damp-proofing infographic
View this helpful damp-proofing infographic, courtesy of Wise Property Care
Updated November 2022 by Jeremy Greer