Waterproofing ponding test: how to check it before tiling
On your checklist as: “Ponding test passed before the waterproofing is covered”
Why — act while you have leverage
Waterproofing is the one layer whose failure is certain to be discovered and certain to be expensive. Once tiles or screed (the levelling layer under a floor finish) go over it, testing means removing them.
What to look at
- Water level marked at the start and re-read at the end
- The ceiling of the room below inspected under light
- Corners and pipe penetrations specifically checked
- Dated ponding test record with photographs of the soffit
Documents to ask for
- Dated ponding test record with photographs of the soffit
How to check it yourself
After the membrane is laid and has cured, the area is ponded and left standing before anything covers it. Common site practice is water held at around 50 mm for 48 hours with the ceiling below checked for damp. Inspect the ceiling below, not only the pond.
Where this comes from: IS 3067:1988 — General design details and preparatory work for damp-proofing and water-proofing of buildings (indian standard or building code)
More waterproofing and painting checks
- Photograph before this is covered
- Painting held until the surface is dry enough to take it
- Paint thinned only as much as the tin allows
- Primer used, and the coats applied in the maker's order
- Putty kept thin — it is a filler, not a levelling layer
- Walls checked for damp and for alkali before the first coat