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Cost guide · 7 min read

How much does damp wall repair cost in Penang?

Damp wall and seepage repair in Penang costs RM450 to RM6,000. See prices for PU injection, wall coating, damp wall treatment and bathroom re-waterproofing.

Published
2 Nov 2026
Updated
2 Nov 2026
Trade
waterproofing

Estimate your cost

RM 1,200 to RM 2,800 total

Assumes 100 sq ft, standard finish, George Town pricing.

This is an indicative estimate, not a quote. Your actual price depends on scope, materials, and site conditions.

Rates reviewed 2026-07-07. Source: cost guide.

Get exact quotes from a local contractor

Damp wall and seepage repair in Penang usually costs RM450 to RM6,000, from a small PU injection job at the low end to a bathroom re-waterproof with tile hacking at the high end. The price depends less on the stain and more on where the water comes from, so the diagnosis decides the bill.

A damp patch is a symptom. Paint over it and it comes back. The four usual sources are rain coming through an external wall, a leak from the bathroom or pipe next door or above, ground moisture rising up the base of a wall, and condensation. Each one has a different fix and a different price.

Find the source first

One simple test helps before you call anyone. Take photos of the patch over a week of mixed weather. A patch that grows after rain points to an outside source, such as a cracked external wall or a failed window joint. A patch that does not change with the weather points to an inside source, such as a bathroom, a pipe, or rising damp.

A stain on the ceiling or the top of a wall under another unit usually comes from the bathroom, kitchen or balcony above. In a strata building, ask your management office how it handles leaks between units before you pay for repairs, because the repair often belongs at the source unit.

A tide mark low on a ground-floor wall, up to about one metre high, with flaking paint and white salt deposits, points to rising damp. This is more common in older landed houses and shophouses than in condos.

The cost bands

PU injection for a leaking slab or crack, RM350 to RM3,000

PU (polyurethane) injection pumps resin into the concrete through small drilled ports. The resin reacts with water, expands and blocks the path the water takes. It suits a localised leak through a ceiling slab or a crack, with no tile hacking.

  • Per-point rates published by Malaysian contractors run from RM45 to RM250 per injection point.
  • Most contractors set a minimum charge per job, in the range of RM350 to RM650.
  • At those rates, an 8-point bathroom ceiling works out to roughly RM360 to RM2,000, and a larger ceiling with more points goes higher.

The point count is set on site, so a low per-point rate does not mean a low bill. Ask for the expected number of points in writing before work starts. Warranties on injection work are short, from 6 months to 3 years depending on the contractor and system.

PU injection does not fix a burst or leaking water pipe. A plumber must repair the pipe first.

Damp wall treatment and repaint, RM800 to RM3,000 per wall

When the source is fixed and the wall must dry out and be made good, contractors quote per wall. Published prices start from about RM800 to RM900 per wall and reach RM3,000 for a larger or worse wall. The price covers the source repair where it is small, mould treatment, a sealer and a repaint.

This is also the band for rising damp treatment on a typical ground-floor wall. The usual fix is a chemical damp-proof course: a row of holes drilled low in the wall, filled with a water-repellent cream, then salt-resistant replastering. The wall then needs time to dry before the final paint.

External wall coating, RM6 to RM18 per sq ft

For rain seepage through an external wall, the fix is on the outside face: crack repair, then a water-repellent or elastomeric coating. Published supply-and-apply rates run RM6 to RM18 per sq ft. A 300 sq ft gable wall at those rates comes to roughly RM1,800 to RM5,400, before scaffolding for high walls.

Coat count matters. A cheap quote often means one coat where the system needs two.

Bathroom re-waterproofing, RM450 to RM6,000

If the damp comes from a bathroom, the long-term fix is at the bathroom floor, not on the wet wall or ceiling.

  • Without tile hacking: surface systems applied over the existing tiles are priced from about RM450 and reach about RM3,500 per bathroom. Some contractors describe these as temporary for many cases.
  • With tile hacking: a full hack, new membrane, screed, water test and retile usually costs RM2,500 to RM6,000 per bathroom, and more for a large master bathroom or a bathroom with pipe and floor slope problems.

For more on membrane types and the pond test, see our waterproofing cost guide.

Price table

Job Typical price Unit
PU injection RM45 to RM250 per injection point
PU injection minimum charge RM350 to RM650 per job
Damp wall treatment and repaint RM800 to RM3,000 per wall
External wall coating RM6 to RM18 per sq ft
Bathroom waterproofing, no hacking RM450 to RM3,500 per bathroom
Bathroom waterproofing, with hacking RM2,500 to RM6,000 per bathroom

Most published price lists come from Klang Valley contractors, because few Penang firms publish rates online. Treat these as planning figures and get at least two Penang quotes.

What changes the price

The source of the water

This is the biggest factor. A leak from the unit above is often a PU injection job or a bathroom re-waterproof at the source. Rain seepage is an external coating job. Rising damp is a damp-proof course plus replaster. Paying for the wrong fix means paying twice.

Hacking or no hacking

Lifting tiles adds labour, debris disposal, a new screed and new tiles. That is why a bathroom job with hacking costs several times more than a surface treatment. It is also the more lasting fix when the old membrane failed across the whole floor.

Access and height

External walls above the ground floor need scaffolding or a gondola, which the per-sq-ft rate does not include. Ceilings in condos may need building management approval and set working hours.

Point count and coat count

PU injection is billed per point and coatings per coat. Both numbers are decided by the contractor, so they are where quotes differ most.

Drying time

A damp wall treated today is not ready to paint today. A contractor who repaints straight away is hiding the problem, not fixing it.

How to compare quotes

  1. Ask what the contractor thinks the source is, and why. A quote with no diagnosis is a guess. Prefer a contractor who checks moisture readings, the unit above, or the outside face before quoting.
  2. Get the method in writing. PU injection, crystalline, elastomeric coating, or full membrane: each one is a different job with a different life.
  3. For injection, ask for the expected point count and a cap. A per-point rate with no estimate can grow once drilling starts.
  4. For coatings, ask for the product, the coat count and the area. "Waterproofing as required" is not a specification.
  5. Compare warranties in years and what they cover. Short warranties on injection work are normal. A warranty with no written scope is worth little.
  6. Check what is excluded. Scaffolding, plumbing repair, tile replacement and the final repaint are often outside the price.

Related guides

Browse waterproofing services in George Town →

Sources

Rates checked against the public sources above on 2 November 2026. Compiled by Wei Han, founder of Penang Renovations.

This guide was drafted with AI assistance from the public sources listed above. Prices are planning ranges, not quotes. If you spot an inaccuracy or have a recent quote to share, contact us at penangrenovations.com@gmail.com.

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Common questions

How much does damp wall repair cost in Penang?
Damp wall and seepage repair in Penang usually costs RM450 to RM6,000. PU injection runs RM45 to RM250 per injection point with a minimum charge of RM350 to RM650 per job. Damp wall treatment and repaint costs RM800 to RM3,000 per wall, external wall coating RM6 to RM18 per sq ft, and bathroom re-waterproofing RM450 to RM3,500 without hacking or RM2,500 to RM6,000 with tile hacking.
How do I find the source of a damp wall?
Take photos of the patch over a week of mixed weather. A patch that grows after rain points to an outside source such as a cracked external wall or failed window joint. A patch that does not change with the weather points to an inside source such as a bathroom, a pipe, or rising damp.
Can PU injection fix a damp ceiling under a bathroom?
PU injection suits a localised leak through a ceiling slab or crack, with no tile hacking, at RM45 to RM250 per injection point. It does not fix a burst or leaking water pipe, which a plumber must repair first. If the old bathroom membrane failed across the whole floor, a full re-waterproof with tile hacking at RM2,500 to RM6,000 is the more lasting fix.