Remove old, mouldy sealant from around your shower tray and apply a neat, waterproof bead to stop leaks.
RS-01Clear the area and ventilateTake out bath mats, bottles and anything else in the shower. Open a window or turn on the extractor fan, since sealant remover and silicone fumes can be strong in a small room. Lay an old towel on the floor to catch scraps of old sealant.
RS-02Cut out the old sealantSlice along both edges of the old sealant bead with a sealant removal tool or a sharp utility knife, angling the blade towards the tray so you don't gouge it. Peel the strip away in one go if you can. Work in short sections rather than trying to do the whole joint at once.
RS-03Scrape and clean the jointUse a plastic scraper to lift any sealant residue left stuck to the tray and tile. Wipe the whole joint with methylated spirit or a dedicated sealant remover to shift limescale, soap scum and old adhesive. Dry the area fully with a lint-free cloth before moving on.
RS-04Treat any mouldIf there's black mould in the joint or on nearby grout, spray it with a mould and mildew remover, leave it for the time stated on the bottle, then rinse and dry the area completely. Sealant won't stick properly to a damp or mouldy surface, so give it time to dry out fully, even overnight if needed.
RS-05Mask the joint for a neat lineRun masking tape along both edges of the gap, keeping the gap width even all the way round. Press the tape down firmly so sealant can't creep underneath it.
RS-06Load the gun and prepare the sealantFit a tube of sanitary silicone sealant into the mastic gun. Snip the nozzle tip at a 45° angle, sizing the opening to roughly match the width of the gap you're filling, usually around 5-6mm.
RS-07Run the beadWorking from one end, run a continuous, steady bead of sealant along the joint, keeping even pressure on the gun. Don't stop and start if you can avoid it, as this leaves lumps.
RS-08Smooth the beadWearing a disposable glove, dip your finger in a little soapy water and draw it along the bead in one smooth pass to leave a neat, slightly concave line. Wipe excess sealant off your glove between passes so you don't drag it back into the joint.
RS-09Remove the masking tapePeel the masking tape away straight away, while the sealant is still wet, pulling it back on itself at a shallow angle. If you wait until it skins over, you'll tear the fresh bead.
RS-10Leave it to cureLeave the shower completely dry and unused for the time stated on the sealant tube, typically 24 hours before it can get wet and up to 7 days before full strength. Don't run the shower, splash the area, or let anyone bath during this time.
RS-11Tidy upBin the old sealant strips and used masking tape. Wipe down the mastic gun nozzle and wash your scraper. Give the bathroom a final wipe so no sealant smears are left on tiles or the tray.
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