Does tanking on a cellar wall mean the cellar is dry?

What is the fuller explanation?

The Property Care Association’s approach is to find the defect rather than sell a treatment for a symptom. A surveyor who was not there when the tanking went on should not certify the guarantee. Ask the seller for the specification, the guarantee and what water it was meant to resist. A missing guarantee is a paper gap. Damp above the line is a building defect.

Maintaining a tanked cellar can include drains and pumps the survey did not switch on. There is no RICS price for re-tanking. If you need to know whether this system has failed, ask a specialist who will say what they will open. Do not sand the coating off before exchange.

What should you ask your surveyor?

• How high does the tanking go, and is there damp above it?
• Did you see a guarantee, or only the coating?
• Is there a pump, and did you test it? You almost certainly did not.

What are the typical next steps?

1. Ask for papers before you believe a slogan painted on the wall.
2. Do not retank the cellar as your first weekend. You may void a guarantee and hide evidence.
3. Read radon separately. A waterproof coating is not a radon test.

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

Which pages should you read next?

• Does the survey test a cellar sump pump?
• What should you ask about a lightwell drain outside a basement window?
• What should you do with a radon result that sits between 100 and 200 Bq/m3?
• Guide: What does damp mean in a home survey?
• All UK home survey questions

Sources

• RICS: RICS Home Surveys (Home Survey Standard)
• Property Care Association: Structural problems, including damp, dry rot, wet rot and woodworm (homeowner advice)
• GOV.UK: Damp and mould: understanding and addressing the health risks for rented housing providers