Waterproofing is the hardest repair to sell and the easiest to get wrong. The work that matters is identifying where the water actually comes from — which is why every serious quote includes a written report and a warranty period.
Full price list
All reference prices are in Hong Kong dollars (HKD).
Every price here is the published starting rate for the work shown, not a quotation. The tradesman prices the job after seeing the site, so parts, transport and access to old buildings can move the final figure.
- Bathroom waterproofing per sq ft
- Roof leak inspection per visit
- External wall seepage repair per sq ft
- Window edge water ingress per window
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Common questions
How is the source of a leak found?
Water almost never comes from where the stain is. A ceiling stain may come from the flat above, a wall mark near a window may be a failed sealant joint, and a floor stain may be a leaking waste pipe in the bathroom. A proper investigation means isolating parts of the system, testing with water and recording the result, which takes time but is what stops a repair being applied to the wrong place. Ask what the investigation involves before agreeing a price.
What different methods are used for waterproofing?
There are three broad approaches: a full strip of the floor and the lower walls, a local repair at the failed joint or gully, or a waterproof layer applied over surfaces that are still sound. They differ in cost and in how long they last, and a coating over a wall that is already leaking from behind will not fix it. The quotation should say which method is being used and how many coats or layers are included.
Why do two waterproofing quotes differ so much?
Much of the difference is about access, not about the material. A window on an upper floor needs a cradle or a suspended platform, a bathroom may need the fixtures removed and the floor taken up, and a flat in a tower block may have no route to the outside wall at all. Ask whether the quote includes the access equipment and the making good afterwards, because those two items can be larger than the waterproofing itself.
How long does waterproofing last, and what does the warranty cover?
The useful life depends on the system, the exposure and how the surface was prepared, and the warranty period should be written down together with the method used. Ask specifically what is covered: re-ponding a failed joint, or coming back if the same area leaks again inside the period. A warranty on a coating does not cover a new leak from a different source, so the written finding about where the water comes from matters.
Who is responsible when the water comes from the flat above?
If the source is a pipe or a bathroom in the flat above, the cost is normally that owner problem, and the management office is the route for raising it. If the source is the building itself, such as a facade joint, the repair is a common part and the owners carry it. Whoever the responsibility sits with, the investigation should be documented before the work starts, and a tenant should not agree to pay for a leak caused by another flat.
How do I check the work, and how long before I use the shower again?
The proper test is a flood test: the area is filled with water and left standing for a set time, then checked underneath and on the ceiling of the flat below. Ask how long the test runs and who checks the flat below. After the work, the waterproof layer or the new screed needs a curing period before the tiles or the water go back, and using the shower too early is the usual reason a repair fails in the first month.
Before you book
Ask for the source of the water to be identified and written down before any waterproofing is quoted, because a repair done in the right place is the one that does not have to be redone. Get the quote to state the method, the area covered, the access needed and the warranty period separately. Find out who checks the flat below and keep the flood test record, and settle the balance only after the work has been tested and the surface has cured.
How the prices work
The reference figures cover the common work of waterproofing a bathroom floor or repairing a window edge, and they are a starting level. A real quote depends on the size of the area, the method chosen, the access, whether the floor has to be taken up and whether the waterproofing is part of a larger job such as a full bathroom refit. A small local repair at an accessible joint sits near the reference figure, while redoing a whole floor in a high flat with no easy access does not.