What this work covers
Kitchen and ancillary waterproofing is targeted sealing rather than a new room-wide membrane. The work identifies small openings below the sink, around pipe penetrations, at exterior window frames, and around air-conditioning penetrations, removes failed sealant, and closes each route continuously with suitable sealant and caps before the finish cures.
When this work is needed
Targeted sealing is useful while pipe penetrations and the lower wall are exposed before the kitchen cabinets go in, after window replacement leaves open joints, or when an air-conditioning penetration connects directly outside. It is not a substitute for diagnosing widespread dampness. If water is entering through the wall, floor, pipework, or window assembly, identify that source before applying more silicone.
Decide before work starts
Even a small sealing job needs a clear location list and division of responsibility.
- Which sink, pipe, window, and air-conditioning penetrations are included
- How much existing sealant will be removed and how each bonding surface will be cleaned
- Which sealant and cap are suitable for each interior or weather-exposed location
- How long kitchen use and window movement must be restricted while the sealant cures
Check in the quote
Use these questions when you review the quote.
- Are all sealing locations and quantities listed or marked on photos?
- Does the price include removing failed sealant and cleaning mould and contamination?
- For exterior window and wall penetrations, is access to the outside face included?
- Are the sealant type, colour, cap, and intended location identified?
- Is there a final check for gaps, lifting, and incomplete adhesion after curing?
If you have photos below the sink, around the window, or at a service penetration, I can help you separate the likely entry route from the areas that actually need sealing.
What to check on site
Targeted sealing should close a known route, not hide an unknown leak. Trace the direction of water and inspect the moving joint first, then prepare and seal only the junctions that need it.
- Target Location and Bonding Surface Cleanup Complete
Inspect the pipe penetrations below the sink, the exterior window perimeter, and the air-conditioning opening to establish where water or outside air can enter. Remove loose sealant back to a sound bonding surface, then clear away dust, grease, mould, and moisture instead of coating over them. - Auxiliary Waterproofing and Cap Sealing Complete
Use backing material where the joint is deep, then seal continuously around pipes, window joints, and the penetration cap with a product suited to that exposure. Do not block a window drainage opening, and check the entire cap perimeter to make sure it is bonded to the wall rather than merely resting against it. - Tooling and Curing Control Complete
Tool the sealant to a consistent width and depth, keeping the start and end points fully bonded. Protect it from water and movement for the stated cure time, then press the cured line gently to check for cracks, open edges, or soft areas before normal use resumes.
Where problems usually start
- Exterior window seal New sealant applied over a failed joint may not bond, allowing rain entry and recurring condensation marks.
- Below the sink and around pipes A break in the seal lets moisture collect in concealed areas, encouraging mould and finish damage.
- Exterior face of an air-conditioning opening A missing cap or incomplete exterior seal can admit rainwater and insects along the service opening.
Cracked silicone is a symptom, not always the root cause. Check contamination, joint movement, exterior water paths, and plumbing leaks before specifying another surface application.
If the wall or floor remains wet away from the joint, stop treating it as a simple sealing repair. The plumbing or window contractor should isolate the route before the area is closed by cabinetry or finishes.
Timing and records
Allow roughly one to two hours for application, but removal of old sealant, drying of the bonding surface, and product curing are additional. Confirm when the work finishes and when water, window movement, and normal kitchen use may safely resume.
Keep separate before-and-after photos for every location, including the original gap or contamination, the prepared surface, the product used, the finished seal line, and the exterior cap. A single wide photo rarely proves that every opening was treated.
These joints are easiest to inspect after the pipework is tested and before cabinets conceal the lower wall. Reviewing the adjacent stages makes responsibility for each opening clearer.