Damp and moisture meters
When a north-facing wall beads with condensation in January, has the damp-proof course failed?
No, beads on a cold north-facing wall in January are moisture from the room air landing on a cold surface, not water rising through a failed damp-proof course. A home survey can record the cold face and any mould. It cannot turn one winter visit into proof that the course has failed.
Last reviewed 24 October 2026. Written for buyers in England and Wales unless this answer says otherwise. No named surveyor has signed this page. It is general guidance, not a report on your house, and not legal advice.
What is the fuller explanation?
A north-facing wall in January is often the coldest surface in a heated room. Moisture from cooking, washing and breathing meets that plaster and drops out as beads or a film. The water sits on the face. It is not a band climbing from the skirting, and it is not a sample taken through the wall. A surveyor can note the orientation, the season and the mould, and still have no evidence that the damp-proof course is missing or broken.
A RICS home survey is a visual inspection of what could be reached that day. It does not guarantee concealed parts, and it does not run the house through a winter. If the skirtings are dry and the mark is only on the cold face, treat the comment as condensation until something else is shown. Wiping the beads does not repair the ventilation or the heating pattern that produced them.
What should you ask your surveyor?
- Was the damp on the cold face only, or did it continue along the skirting?
- Did you record that the wall faces north, or only that a meter responded?
- Would the same sentence stand if the room were steadily heated and ventilated?
What are the typical next steps?
- Photograph the wall and note whether the beads return on the next cold morning.
- Do not commission a damp-proof course because a north wall sweated in January.
- Ask how the room is heated and ventilated before you treat the plaster as saturated.
Costs vary with the building and with who you instruct. Where this page does not cite a published figure, ask the surveyor, a relevant specialist, or your solicitor for a written quote. Do not treat a forum average as the price.
Also asked about this
Does a moisture meter on that cold plaster prove saturation?
No. A surface meter can respond to condensation and to salts. It does not, by itself, show water rising from the ground.
If the same wall is dry in June, was the course repaired?
Not necessarily. Summer air and a warmer wall can stop the beads. The course may never have been the issue.