How do surveyors check for damp?

By 19 July 2021Blog, Damp

Surveyors at PSS use three main methods to identify damp within your home. The first and most obvious method is a visual inspection of your property. If there are dark patches on walls, signs of condensation and mould can be all signs of damp. Surveyors will also use an electrical conductance moisture meter (a damp meter) to measure levels of moisture in walls and timber, we will also use a powerful thermal imaging camera that can see the temperature differences within the walls (internally and externally) ceilings and floors.

The thermal imaging camera can also find leaking services (water pipe, sewage pipes) and water behind render etc…

What is involved in a damp survey?

When undertaking a damp survey, we will often start with an external inspection of the property to ascertain if there are any external defects that are causing water ingress. Some examples of this would be:

  • Problems with the roof, roof tiles, lead flashing, chimney stacks, render to ridge tiles and verges etc…
  • Leaks in the rainwater pipes, the general water flow off the building when raining (is water running off the building and not into the guttering)
  • A deterioration in the brick, stone and pointing.

Your surveyor will also make internal investigations by checking for signs of damp. Some examples would be:

  • Mould growth
  • Wall plaster blistering
  • Deterioration of timber or skirting boards
  • Musty odors
  • Tide marks above the skirting boards
  • Peeling wallpaper

This is only a brief summary of what we would check to get to the source of the damp problem.

Once all of the checks are complete your surveyor will be able to create a report outlining the findings. You can see an example of one of our damp reports here.

We will give you a clear summary of how to solve your damp problem.

Can damp cause structural damage?

Damp can cause problems such as wet rot and dry rot. Wet rot is the most common and occurs when timber is very damp, typically has a moisture content of 50%. The wet rot fungus will grow if the timber stays wet and left will damage or destroy the structural integrity of the timber.

However, dry rot can be a more serious problem. It can grow in timber with moisture content as little as 20%. This fungus can spread across the house in the search of more wood, it is harder to catch, more difficult to get rid of, and requires more specialized treatment. Dry rot will have the same effect as wet rot, it will damage or destroy the structural integrity of the timber in your home.


Can you sell a house with damp?

If your house has damp you will probably still be able to sell it. However, if damp is found it could affect the valuation of your property. Prospective buyers will be put off if significant damp is found and could potentially pull out of the sale or wish to renegotiate the offer as they will likely need to pay for remedial works to be carried out.

Therefore, if you can afford the repairs required to fix a damp problem it would be a good idea to do so.


Damp can cause a variety of issues including structural problems because of wet and dry rot. It could also make your property harder to sell or lower the value of the property. Therefore, getting a surveyor to investigate a potential damp problem can save a lot of money and headaches in the future.

If you are worried that you have got a damp problem, get in touch with us today, to arrange a damp survey of your property.