Damp and moisture meters
Does an old chemical damp-proof course guarantee mean the wall is dry now?
No. A guarantee is a contract about work that was done, if you can find it and if it still has a named installer. It is not a test result for today. The wall can be dry, still wet from another cause, or wet again because the outside levels were never changed.
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?
Injected courses were sold for decades against “rising damp”. Some were a reasonable part of a larger repair. Some were sold off a meter reading. The paper in the drawer does not show whether the plaster was replaced, whether the path was lowered, or whether a leak was fixed. A surveyor may note that injection holes are visible. They are not the guarantor and they do not enforce the policy.
The Property Care Association expects a diagnosis before treatment. Government damp guidance is about the cause and the health risk, not about honouring a private guarantee. Ask the seller for the guarantee, the date, the areas treated and whether it is insurance-backed. Then read the survey sentence beside it. If the wall is stained now, the guarantee has not answered the cause.
What should you ask your surveyor?
- Could you see injection holes, or only a mention in the papers?
- Is the wall stained now, or is the guarantee the only evidence?
- Does your recommendation depend on the guarantee being valid?
What are the typical next steps?
- Ask the seller for the guarantee and any re-plastering invoice. Do not assume it transfers to you.
- Do not buy a second injection because the first one has a logo on it.
- If there is active staining, investigate the cause. The paper is not the investigation.
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 guarantee transfer when you buy?
Only if its terms say so, and often only if the company still exists. Your solicitor can ask. The surveyor does not novate it.
Are injection holes a defect?
They are evidence of past work. They are not, by themselves, a condition rating.