10 Signs Your Building Needs Waterproofing (Check Before You Buy)

Water damage is the defect most often hidden before a resale viewing and most expensive to discover afterwards. These are the signs worth knowing, whether you are buying or maintaining.

1. Fresh paint on one wall only

A single recently painted wall or ceiling patch in an otherwise older finish is the classic pre-sale cover-up. Ask directly when and why it was painted.

2. White crystalline deposits

Efflorescence — salts carried out of masonry by moisture. It means water has been moving through that wall, whatever the current surface looks like.

3. Blistering or flaking paint

Paint lifting off in sheets or bubbles means moisture is trapped behind it. Paint does not fail this way on a dry wall.

4. A musty smell in closed rooms

Particularly in bathrooms, basements and rooms that stay shut. Smell is often the earliest sign, before anything is visible.

5. Ceiling stains, especially in corners

Brown or yellow rings on a ceiling indicate water has come through the slab. In a top-floor flat that points at the terrace; lower down it usually points at the bathroom above.

6. Cracks in external walls

Look particularly around window frames, at floor-level junctions and near the parapet. Fine cracks are water paths even when they look cosmetic.

7. Damp or cold patches on walls

Press the back of your hand against suspect areas. A patch that feels noticeably colder than the wall around it usually holds moisture.

8. Black spotting in bathroom corners

Mould growth indicates persistent moisture. Sometimes ventilation, sometimes a leak — worth distinguishing before you buy.

9. Standing water marks on the terrace

Ask to see the terrace. Silt rings show where water ponds, and ponding is what converts small defects into leaks.

10. Damp on the wall below an overhead tank

Almost always the tank rather than the wall, and it will not resolve on its own.

If you are buying

View during or just after rain if you possibly can — the monsoon is the honest season for a building. Ask the society about past leakage complaints and any waterproofing done. If in doubt, get an independent inspection before you commit; it costs a fraction of the repair.