Waterproofing
Flat Roof Waterproofing in Singapore: What to Know
Flat roofs and roof terraces — common on landed homes and buildings — are among the hardest-working surfaces to keep watertight. Standing water, intense sun and movement all test the waterproofing. Here’s what to know.
Key takeaways
- Flat roofs face ponding, UV and thermal movement — demanding conditions.
- They need a durable membrane and proper drainage falls.
- Signs of failure: leaks and stains on the ceiling below.
- Getting the falls and detailing right is as important as the membrane.
Why flat roofs are demanding
Unlike a pitched roof, a flat roof lets water sit if the falls aren’t right, and it bakes under direct sun while expanding and contracting with heat. That combination punishes waterproofing, so the system has to be robust and correctly detailed.
What proper waterproofing needs
A lasting flat-roof system combines a durable membrane (suited to UV and movement), correct falls to drainage so water runs off rather than ponds, and careful detailing at edges, upstands and outlets — see our guide to membrane types.
Catching and fixing leaks
Ceiling stains or drips below a flat roof mean the waterproofing has failed somewhere. As with all leaks, the fix starts by finding the source and restoring the membrane and drainage — not just patching the stain inside.
Frequently asked questions
Why do flat roofs leak? Ponding water, UV and movement degrade waterproofing, especially with poor falls or detailing.
What waterproofing suits a flat roof? A durable, UV- and movement-tolerant membrane with correct drainage falls.
How do I know my flat roof is leaking? Stains or drips on the ceiling below are the usual signs.
Can it be fixed without redoing the whole roof? Sometimes — after finding the source; larger failures need re-membraning.
Flat roof leaking?
We waterproof flat roofs and terraces with proper membranes and drainage. See our waterproofing service. Get a free assessment.
