Window leak repair and resealing in Singapore.

Because wind pushes rain past the outer seal of the frame faster than the frame's weep holes can drain it. Perimeter sealant that has hardened, cracked or let go, blocked weep holes and a sill that holds water all cope with a light shower and fail in driving rain. Watch the window during a storm and note where water shows first: that is where the repair starts.

Water at the corners of the frame, under the sill or along the junction of frame and wall is the window: sealant, weep holes or sill. Water above the head of the frame, or along a crack running out from a corner of the opening, is the wall: the corners of window openings are where external walls crack most. A damp patch away from the window that spreads after rain is porous render. The applicator checks outside, in the rain if need be.

A Singapore repair platform's price page, read on 20 October 2026, puts window sealant replacement at S$5 to S$15 per metre depending on the material, plus the call-out; a window has a perimeter of a few metres. Clearing the weep holes and correcting the sill are usually done on the same visit; a glazing gasket is quoted by a window contractor; a crack in the wall beside the frame is quoted as a crack repair. These are published market ranges, not Rayson quotations.

The failed sealant is cut out completely rather than covered, the joint is cleaned and primed, a backer rod is fitted where the gap is deep, a flexible sealant compatible with the frame and the wall is applied and tooled, the weep holes at the bottom of the frame are cleared, and the sill is checked for its outward fall and flashing. One window usually takes a few hours; the sealant needs dry weather to skin over, and the cure time depends on the product used.

It depends on whether the wall around the window will be coated afterwards. Silicone weathers well, but no coating bonds to it. MS-polymer and polyurethane sealants can be painted and work with an elastic wall coating applied later. Where the surround is to be coated with SealForce AC10, the applicator uses a paintable sealant. The sealant is specified by the applicator for now; this page will be updated when Rayson's own sealant is released.

HDB's maintenance guide, updated 17 August 2026: windows are fittings within the flat, maintained by the owner, checked at least every six months (check, clean, change), and repaired by a BCA-approved window contractor from HDB's directory; a window that falls for lack of maintenance can bring a fine of up to S$20,000 and/or up to a year's jail. The perimeter sealant is the owner's; a crack in the external wall beside the window is the Town Council's. New flats carry a five-year warranty on external seepage.

The window usually belongs to the unit and the external wall is common property, and the sealant sits exactly where the two meet, so the answer depends on the development's strata title and by-laws. BCA's Strata Management Guide 13, first published November 2023: seepage that originates from common property is the management corporation's to repair. A building over 13 m and 20 years old also carries a façade inspection every seven years, and failed sealant joints are a routine finding for the management corporation to rectify.

A bead over old sealant usually leaks again within months: the new sealant bonds to the failed sealant, not to the frame and the wall. A repair that lasts cuts the old sealant out, cleans, primes and reseals. Working outside a window on an upper floor is also a fall risk, so it is work for an applicator with the means to reach it safely.

Report it to HDB first. Within the defects liability period HDB rectifies maintenance issues in a new flat, and external seepage carries a five-year warranty. Attach photos taken during rain and say exactly where the water shows.

Not the window, but the same repair. The aircon pipes and cable pass through the wall or the frame beside the window, and the sealant around that penetration ages like the window sealant; rain then follows the pipe in. The applicator reseals the penetration and checks that the trunking falls outward.

Rayson quotes and contracts the job, and an applicator in the Rayson network inspects and does the work, under the workmanship warranty set out in Rayson's quotation; a glazing gasket or the frame itself is replaced by a window contractor, which in an HDB flat must be BCA-approved. Rayson makes SealForce AP05 primer, SealForce AC10 elastic coating and PatchBond TX80 for the wall around the opening and publishes their data sheets; the sealant is specified by the applicator for now.

HDB's guide sets no interval; it asks owners to check their windows at least every six months. Sealant hardens, cracks and pulls away under Singapore sun, so it is replaced when a check finds it cracked, hard or detached, not on a calendar. Façade contractors in Singapore commonly plan exposed sealant joints on a cycle of several years; one contractor's 2026 guidance works to five. Check the windows on the weather side of the building first.

Policies differ. Many Singapore home insurance policies cover sudden water damage to contents and renovation and exclude gradual seepage, wear and tear, and the cost of resealing the window itself. Check the policy wording, photograph the damage and the window during rain, and keep the quotation and the invoice; the insurer will ask for them.

Photos of where the water shows inside, ideally taken during rain; photos of the frame and sill from outside; the number of windows and their rough size; the property type and floor; when the leak appears; and any façade-inspection finding. We respond within one working day and arrange the site inspection by an applicator from our network.