Silicone Resealing
Shower, Sink & Window Joints

Every RM figure on this page is one ClickBina already publishes elsewhere on this site, for the job that page prices, and each one is attributed in the text. Where the corpus prices nothing, this guide stays deliberately price-free and gives you the cost drivers and the quotation lines instead of an invented number. WhatsApp us a photo of the joint for a quote.

What resealing is — and what it is not

A sealant bead is a flexible gap-filler doing one job: closing a junction between two materials that move independently of each other. A glass shower screen and a tiled kerb expand at different rates and get knocked in different directions; a sink and a worktop are two separate things pretending to be one surface. Sealant absorbs that difference. Grout, mortar and filler cannot, which is why they crack out of exactly those junctions within months.

Resealing is the renewal of that bead, and the operative word is renewal. The joint is cut back to bare substrate on both faces, cleaned, dried, and a fresh bead is gunned and tooled into it. What is very commonly sold as resealing — running a new white line over a grey, split, mouldy old one — is not resealing at all. It looks right for a fortnight and then lifts in one piece, because the new material bonded to old cured sealant rather than to the tile and the glass. Everything else on this page follows from that single point.

It is also worth saying plainly what a bead is not: it is not waterproofing. The membrane under your bathroom tiles is what keeps water out of the slab, and a perfect bead cannot rescue a failed one — see bathroom waterproofing costs for what that layer is and what it costs. Nor is it grout. Grout fills the lines between tiles and is rigid; sealant fills the junctions where planes change or materials meet and is flexible. Our grouting versus waterproofing guide separates the three jobs.

When a bead needs replacing, not cleaning

Not every ugly bead is a failed bead. Surface mould on an otherwise sound, well-adhered joint often cleans back with a household mould remover and patience, and a bead that is merely discoloured is doing its job. The signs that the joint is finished rather than dirty are mechanical, not cosmetic:

• It has pulled away from one face. A dark line or a visible gap along one edge means adhesion has gone on that side, and water is already behind it.
• It has torn down the middle. A split along the centre line usually means the bead was bonded on three sides and could not stretch when the joint moved.
• It lifts when you press it. A bead that springs away from the substrate under a fingernail is not attached any more.
• The mould is under the surface, not on it. Black staining that will not clean off has grown into the body of the material, usually through water sitting behind the bead.
• It has gone hard and crazed. A bead that is brittle rather than rubbery has aged out and will crack at the next movement.
• It was never right. Sealant smeared wide across the tile face rather than formed into the joint is a wider mess, not a wider joint, and it peels off the face first.

One more trigger worth naming, because it is the commonest in rental property: handover. A tenancy-end inspection that flags mould in the grout and silicone is flagging a maintenance item, not necessarily damage — our common rental unit damage guide sets out how that is usually treated and publishes re-siliconing at RM150–RM300 and re-grouting at RM200–RM600 in that context.

Why the old bead has to come out completely

This is the technical heart of the subject and it is not negotiable. Once silicone has been used on a joint, that joint is a silicone joint until somebody mechanically cuts the old material out and cleans the substrate back on both faces. Nothing bonds reliably to silicone residue — not fresh silicone, not paint, not another sealant family. A thin, invisible film left on the tile is enough to guarantee the new bead lifts, which is why a reseal that fails within weeks almost always failed at the preparation stage rather than in the tube.

Removal is therefore the bulk of the work and the bulk of the skill. The old bead is cut out with a blade along both faces and lifted in one piece where possible, the corners and stop-ends are picked clean, and the residue film is removed mechanically. On glass and glazed tile this is straightforward. On a matt porcelain, a natural stone or a painted surface it is slower and needs a lighter hand, because gouging the substrate creates a rough face that will not seal cleanly and, on a porous stone, can leave a permanent mark.

Then the joint has to be genuinely dry. Sealant will not bond to a damp face, and a shower that was used that morning is not dry inside the joint however dry it looks. This is the single reason a reseal takes longer than people expect, and the reason a rushed job done between two other visits on the same afternoon is a job you will be paying for twice.

Sanitary grade, acetoxy and neutral cure

For interior wet areas the sealant of choice is a sanitary-grade silicone — a silicone formulated with a fungicide so the bead resists the mould growth that a shower joint invites. That is what a competent trade quotation means by “mould-resistant sanitary grade”, and it is worth insisting on by name rather than accepting whatever tube is in the van. A general-purpose tube in a shower is a false economy measured in months.

Silicone comes in two broad cure types and you can tell them apart by nose. Acetoxy-cure silicone smells strongly of vinegar while it cures, because it releases acetic acid; it is the cheap general-purpose tube, and that acid is why it is generally unsuitable on cementitious surfaces and on many metals, where it can corrode or attack the substrate. Neutral-cure silicone has little or no vinegar smell and is the type normally specified for construction and glazing work. If a tube smells strongly of vinegar and it is about to go against render, concrete or metal, that is worth stopping for. Our PU versus silicone guide goes through the cure types, the substrate lists and the primer question in full.

Two properties of silicone are worth knowing before you choose it for a visible joint. Ordinary paint does not stick to ordinary silicone — it beads while wet and flakes once dry — so a joint on a surface that will be repainted is not a silicone joint. And silicone tends to attract and hold airborne dust, so a bead in a visible position can read as a darker line after a couple of years. Both are decisions to make deliberately before the gun comes out, and both are covered in depth on that comparison page. The tube itself is cheap either way: our DIY sealants guide puts a tube of decent sealant at RM15–RM40, which tells you that the money in a reseal is preparation and labour, not material.

Joint shape, backer rod and two-sided adhesion

Joint design beats product choice, and it does so consistently. A correctly formed joint filled with an adequate sealant outlasts a badly formed joint filled with the most expensive tube on the shelf. Four principles do nearly all of the work, and none of them needs a number to understand.

• A bead must be wide relative to its depth. Sealant accommodates movement by stretching across the joint, so a deep narrow plug is thick in exactly the direction that does not help. Manufacturers publish the ratio and the minimum and maximum depth in their application guides — ask for the figures for the product actually being used.
• Two-sided adhesion, never three. The bead should stick to the two opposing faces of the joint and not to the back of it. Bonded on three sides it cannot stretch when the joint opens, and it tears — usually straight down the middle. That one mechanism explains a very large share of failed joints.
• Which means a backer rod, or a bond-breaker tape. A closed-cell foam rod pushed into the joint to a consistent depth stops the sealant bonding to the back and sets the depth of the bead at the same time. Where the joint is too shallow for a rod, a bond-breaker tape across the back does the first job.
• Tool the bead. Pressing the bead into the joint after gunning forces the sealant into contact with both faces so it actually wets them. A bead laid on and left proud is bonded far less than it appears to be, and it collects dirt on its raised face.

Preparation sits underneath all four: sound, clean, dry faces, free of dust, oil, old sealant and loose coating. A sealant is only ever as good as the two faces it is holding on to.

Joint by joint: shower, bath, sink, worktop, WC, window

Different joints fail for different reasons, and the fix is not identical:

The window row deserves a note. An internal reveal bead is cosmetic and draught-related; the joint that stops rain is on the outside of the frame, and it is a different specification because it is exposed to sun and often to paint. If water appears on the sill after rain, reseal nothing until the entry point is found — our window leak repair guide walks through the five entry paths, and our window repair guide covers the hardware side.

How a proper reseal is done

The sequence is short, and every step in it is a step people skip:

• Cut out. Slice along both faces and lift the old bead in one piece where possible; pick the corners and stop-ends clean.
• Remove the residue. Mechanically, from both faces, until the substrate is genuinely bare.
• Clean and dry. Degrease, remove soap film and mould, and let the joint dry properly — not visually, actually.
• Back the joint. Backer rod or bond-breaker tape where the joint is deep enough to need it.
• Mask if the substrate is porous or textured. It makes a clean line and protects a matt tile or a stone face from smear.
• Gun and tool. One continuous pass, then tool the bead firmly into the joint so it wets both faces. Remove masking while the sealant is still wet.
• Cure before use. No water, no shower, no washing down until the product’s stated cure period has passed. This is the instruction most often ignored and it ruins otherwise good work.

How to check it afterwards: the bead should sit in the joint, smooth and slightly concave, not proud like a sausage on the surface; it should be continuous through corners and stop-ends with no gaps where the crew paused; and there should be no sealant smeared across the tile faces on either side. Photograph the stripped joint before it is filled — that photo is the only evidence you will ever have that the old material actually came out.

Black mould: surface growth or a failed joint

Black spotting on a bead is the most common reason people call, and it has two quite different causes. Surface growth sits on top of a sound, well-adhered bead and is a ventilation and cleaning problem: a Klang Valley bathroom with no extract and a screen that never dries will grow mould on anything. That cleans back, and it will come back again unless the room is ventilated. Growth inside the material, or along a line where the bead has lifted, means water has been sitting behind the joint — and no cleaning product reaches behind a bead. That one is replaced.

The distinction matters because resealing a joint whose real problem is standing water behind the tiles buys you a few months and nothing more. If the tiles around the joint sound hollow, if the grout stays dark long after the room has dried, or if there is a stain on the ceiling below, the sealant is a symptom. Start at shower floor leak repair or inter-floor leakage instead, and treat damp walls as their own problem via our damp and mould treatment guide.

What resealing costs in the Klang Valley

Resealing is small-job work, which means the visit economics matter as much as the joint. These are the figures this site already publishes, each from the page named:

Two things fall out of that table. First, a single joint on its own visit is dominated by the callout and the minimum charge, so batch the work — every bead in the bathroom, the kitchen sink and the worktop in one visit costs far less per joint than three separate calls. Second, the material is a small fraction of the price, which is why the discipline in the preparation is what you are actually buying.

When resealing is the wrong fix

ClickBina reseals shower screens, baths, basins, worktops and window reveals across the Klang Valley — full cut-out, residue removal, sanitary-grade sealant, tooled properly and handed over with a cure instruction. Batch several joints into one visit and the price per joint drops sharply. See also bathroom waterproofing and kitchen countertops for the layers either side of the bead.