Bathroom Silicone

A black line at the shower tray in a student bathroom is often failed sealant, sometimes a leak, and occasionally both. Fresh silicone is a turnover job when the joint is dry and the water is staying in the tray. It is not a way to hide a wet wall. ManjeProp would rather recaulk a clean joint than paint over a smell.

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When silicone is the right job

The tray, bath or basin is firm
The wall is dry when it has not been used for a day
The old seal is cracked, peeled, or missing
There is no soft plaster, no brown ceiling below, no tide mark climbing the paint

If the wall is cold, soft, or the downstairs ceiling is stained, stop. That is moisture behind the finish. Ticket it as a leak. Silicone on a wet joint fails and it hides the evidence we need.

What to buy

Sanitary / bathroom-grade silicone that the tube says is for wet rooms. Not builder’s acrylic gap filler, not kitchen-only if the label excludes showers, not a “universal glue.”
Mould-resistant on the label is normal for sanitary tubes. It is not a miracle. Ventilation and a squeegee still matter in Durban humidity.
Colour that matches the house: usually white on white sanitaryware. Clear if the joint is between two colours and we have used clear there before. Do not mix white and clear on one tray.
A cartridge for a skeleton gun if we are doing a house. A small squeeze tube for a 30 cm repair. Open cartridges skin over; do not buy a crate for one basin.

A cheap gun that drips will make a mess you then have to cut out. A decent skeleton gun is a once-off.

The job

Dry the room. A fan and a day without showers beats “wiping it.”
Cut out the old seal. All of it. Residue is why the new bead lets go.
Check the gap. A hole at the back of a tray is a plumber or a tray-reset, not a thicker bead.
Masking tape if you want a clean edge. Worth it in a room we will photograph for a listing.
Tool the bead. Soap solution or a proper tool, not a finger full of cigarette ash.
Cure time as the tube says. Do not run the shower that night because a viewer is coming in the morning.
Photograph before and after for the ticket. Ventilate.

Do not silicone over black mould without cleaning and without asking why the mould is there. Do not silicone a tap flange shut so the next person cannot service it. Do not silicone a window that is actually a leak.

Tenants

Keep water in the tray. A cheap squeegee and the extractor (if the house has one) do more than a second tube. Report a new stain, a soft wall, or a smell. Report a fault. Category Water / leak or General maintenance. Photograph the joint and the stain.

Do not recaulk the shower yourself the night before you leave and hope the outgoing photos are dim. We photograph in daylight. Fresh silicone over a wet chip is obvious.

Do not pour bleach into a joint and then close the door. Ventilate if you clean.

Buying

Hardware counter so you can read the whole tube. Marketplace is fine for a named sanitary silicone and a gun if you already know the colour. Avoid “7-in-1 miracle seal” gels that promise to seal a leak in a pipe — that is not this job.

This article names no brand and no price. The right tube is bathroom-grade, the colour we already used, and still soft in the nozzle when we start.

What this is not

It is not a tenant humidity app. We do not fit sensors that log who showered. We do not need a brand of silicone that wants an account.

It is not a substitute for an extractor that has died, or for a house rule that ten people shower with the door shut and the window painted closed. Fix the ventilation path when that is the problem.

Owners: budget a recaulk at turnover for showers that get daily student use. It is cheaper than a downstairs ceiling.