Black Sealant? We Remove It Fully and Seal It Right in Kenilworth

Why the sealant went black

The black staining on bathroom sealant is mould growing on and within the silicone itself. Silicone is slightly porous to moisture over time, and in a room that stays warm and humid — a bathroom used daily with the door shut — spores settle into the bead, feed on the residue left by soap and shampoo, and spread through the material. Surface cleaners can bleach the outside of the bead, which is why a scrubbed sealant strip looks better for a fortnight and then darkens again. Once mould is inside the silicone, no amount of cleaning removes it, because the material it is living in has to go.

What mould in the bead really means

Mouldy sealant tells you two things. First, that the seal has reached the end of its life and needs replacing — that part is straightforward. Second, and worth pausing on, that the room stays damp long enough for mould to thrive. That can simply be how the household uses the bathroom, but persistent mould along a joint, or mould that returns quickly after resealing, often points to something more: poor ventilation, a cold wall, or moisture finding its way from somewhere it should not. We will not pretend a fresh bead fixes the room's dampness, and if we see signs of a leak or persistent condensation, we will say so — resealing a joint above an active leak, or in a room whose ventilation is failing, just resets the clock on the same problem.

Removing the old seal

The mouldy sealant is cut out in full, every stretch of it. This is more laborious than it sounds: mould roots into the bead and often into the grout line or joint edge behind it, so the job means slicing the silicone, lifting it in strips, and picking fragments from the joint until nothing contaminated remains. Cleaning over a mouldy bead, or sealing a new bead over an old one, leaves the mould in place — it reappears through the new sealant surprisingly quickly. Where the mould has marked the tile or grout beneath, we clean the surfaces as far as the material allows and tell you if any staining is likely to be permanent.

Reseating with the right product

Once the joint is stripped, it is cleaned and dried thoroughly — damp is the enemy of a lasting bond, and a freshly showered bathroom will need to wait. The new bead is a sanitary-grade silicone with mould-resistant treatment built in: it slows regrowth noticeably, though in a humid room no sealant is mould-proof, and we will not claim otherwise. Colour is agreed in advance — white and clear are the usual choices — and materials are quoted separately from the labour, so the product is settled before work starts.

Cure and keeping it clean

New silicone needs its full cure time before it meets water, typically several hours to a day depending on the product and room conditions. We will tell you the exact waiting time and how to look after the bead: squeegee or wipe down the joints after showering, keep the extractor fan running or the window open after use, and clean with a non-abrasive product. Those habits do more for the life of the seal than any product claim.

The limits — ventilation and leaks

A replaced seal fixes the seal. It does not fix a bathroom that never dries out, a wall that stays cold, or a leak behind the tiles, and we do not describe a reseal as curing mould or as a watertight guarantee. If the room has no working extractor, if mould reappears on walls and ceiling as well as joints, or if there is any sign water is entering from elsewhere, the lasting answer lies in ventilation, heating or plumbing — and we will refer that work rather than reseal over it. Mould that raises health concerns is a matter for the right advice; our scope is the sealant and an honest assessment of what we can see.

Preparing the bathroom

Leave the bath or shower unused and dry beforehand if you can. Clear bottles and caddies from the joints being worked and pull the bath mat away. If the mould covers a large area or several rooms, say so at booking so enough time is allowed for a proper strip-out.

Booking

Book online or by phone. A booking fee is paid when you book, the hourly rate depends on how soon you need the visit, and the full cost is confirmed with you before work begins. Same-day appointments may be available.