Building guides
Why does damp keep coming back after you repaint?
Because paint covers the stain, not the water. Damp comes back until the source is fixed: usually the roof or parapet, a leaking pipe inside the wall, moisture rising from the ground, or rooms that can't breathe. Find the source first, fix it, then repaint, and do it before the monsoon.
Why doesn't repainting work?
A damp patch is a symptom. Water is reaching the wall from somewhere, and as long as it keeps arriving, new paint will blister, peel and stain again, often within one rainy season. Anti-damp paints can slow it down. They can't stop water that is still coming in.
Where does the water come from?
In Dhaka's buildings the cause is usually one of these:
- The roof and parapet. Cracked roof slabs, worn-out waterproofing, blocked roof drains and the joint where the parapet meets the roof let rain in. It shows up as damp on top-floor ceilings and on the upper parts of walls.
- Pipes inside the walls. A slow leak in a concealed pipe, or a bathroom with failed waterproofing on the floor above, keeps a patch wet all year, rain or no rain.
- The ground. Without a working damp-proof course, moisture rises from the ground into ground-floor walls. You see a tide mark a little above the floor and salt crystals on the surface.
- Rooms that can't breathe. Bathrooms and kitchens without enough ventilation trap steam, which condenses on cold walls and ceilings and grows mould.
- Openings in the outer walls. Gaps around windows, AC pipe holes and cracked plaster let wind-driven rain in during heavy storms.
How do we find the source?
We read the building before we touch the wall:
- Where is the stain? Is it under the roof, below a bathroom, on an outer wall, or near the floor?
- When does it appear? Only after rain points to the roof or the outer walls. All year points to plumbing or the ground.
- What is around it? We look at the roof, the pipes, the floor above and the outside of the wall, not just the patch itself.
You get the cause in writing, with photos, before any repair is priced.
When is the best time to fix damp?
Before the monsoon. Repairs to the roof and outer walls need dry weather to cure, and the heavy rain is what shows whether the fix worked.
How we help
Our damp-proofing and repair work starts with that diagnosis. Then we fix the cause, whether that is waterproofing, plumbing or ventilation, and repaint only once the wall is dry. The inspection is part of our free building health check.