Internal sealant removal and replacement
Failed sealant in a bathroom, kitchen or wet room is not just unsightly. Mouldy, split or missing silicone allows water to work behind wall surfaces and under floors - and once water reaches the structure beneath tiles or boards, the damage is expensive to put right.
We remove failed internal sealant completely, treat the surfaces and replace it with sanitary-grade material. It is one of the most common jobs we carry out across Bradford and Leeds, and it is one where doing it properly makes a significant difference.
When internal resealing is required
Internal sealant replacement is necessary when:
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Silicone has pulled away from one or both surfaces
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Black mould has penetrated through the sealant body
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The joint is visibly cracked, split or missing in sections
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There is water escaping behind a bath panel or under a shower tray
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The joint looks clean on the surface but is soft, porous or deteriorating underneath
Surface cleaning temporarily removes the appearance of mould, but once spores have penetrated into the sealant body, the mould will return. The only reliable fix is full removal and replacement.
Why old sealant must be fully removed
Applying new sealant over old material is the most common reason internal resealing fails early. Old silicone - even if it looks intact - leaves a residue that prevents new sealant from bonding properly to the tile or tray surface beneath. Without a proper bond on both sides, the new joint will lift, crack or separate far sooner than it should.
Beyond adhesion, old silicone is frequently colonised with mould deep in its structure. Sealing over it traps that mould, which continues to grow through to the new surface - often within a few months.
Full removal is not optional. It is the only way to get a long-lasting result.
What "sanitary grade" means
Not all silicone sealants are the same. Sanitary-grade silicone is formulated with an antimicrobial additive that inhibits mould growth and is designed for continuous exposure to moisture and cleaning products.
Standard silicone - the kind sold in a general DIY store - lacks this protection and degrades noticeably faster in wet environments. We only use sanitary-grade materials for bathroom, shower and wet room work.
Our internal resealing process
The full process, step by step:
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Score the joint - run a blade along both sides of the existing sealant to release it from the surface without damaging tiles or the bath/tray
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Remove all old sealant - full mechanical removal of the sealant body; no residue left behind
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Clean the substrate - both surfaces are cleaned and degreased to remove soap residue, limescale and any contamination that would prevent adhesion
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Treat for mould if required - where mould has reached behind the sealant line, surfaces are treated before new sealant is applied
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Apply sanitary-grade sealant - the correct product for the substrate, applied to fill the joint without voids
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Tool to a smooth profile - the bead is tooled to a tight, smooth finish that does not hold standing water
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Allow to cure - sanitary silicone typically requires 24 hours before the area can be used
Where we work and what we cover
We carry out internal resealing in:
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Bath-to-wall and bath-to-panel joints
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Shower tray to wall and shower enclosure joints
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Sink-to-worktop and sink-to-wall joints
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Kitchen worktop-to-wall junctions
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Window board joints in wet rooms and bathrooms
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Wetroom floor-to-wall perimeters
Internal resealing is consistently one of the most requested services we carry out across Bradford, Leeds and the surrounding areas - partly because it is one of the most commonly done badly.
What you need to do before we arrive
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Clear the area of products and accessories around the bath, shower or sink
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The area should be dry if possible - if there is significant mould or moisture, let us know in advance
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The bath, shower or sink should be accessible from at least one side without obstructions
Frequently asked questions
Q1. How long before I can use the shower or bath again? Sanitary silicone typically requires 24 hours to cure fully before the area should be used. In a well-ventilated bathroom, this is usually sufficient. We will advise based on the specific product used. Q2. Can mould be cleaned instead of removed? Surface cleaning is temporary. Once mould has penetrated into the silicone body, it will return through any new sealant applied over the top. Full removal is the correct fix. Q3. Do you work in both bathrooms and kitchens? Yes. We reseal all internal wet-area joints - baths, showers, sinks, worktops and wet rooms. Q4. How long does new sanitary sealant last? With proper surface preparation and sanitary-grade materials, internal sealant in a normal bathroom should last between 7 and 12 years, sometimes longer in low-use areas. Q5. Can you reseal just one section, or does the whole run need replacing? We recommend replacing the full run in most cases. Joining new sealant to old creates a weak point at the junction, and if the existing sealant is discoloured or aged, the section needing attention usually indicates the rest is not far behind. Partial repairs also create a visible colour difference between old and new material. Q6. What is included in the price? Our service covers full removal of the old sealant bead, cleaning and preparation of the joint, mould treatment where required, and application of a correctly sized new bead in sanitary-grade material. We leave the area clean. We do not carry out tile repairs, grout replacement or plumbing work - if we identify related issues, we will point these out so you can arrange them separately.
Not sure if this is the right repair?
If you are seeing damp in unexpected places and are not sure whether failed sealant is the cause, a Building Leak & Damp Inspection will identify where water is getting in before any work begins.