To seal leaking shower grout, remove any loose or cracked grout, clean and dry the joints, apply compatible replacement grout and let it cure as directed. If the grout manufacturer requires sealing, apply a compatible shower grout sealer. Sealer reduces moisture absorption but cannot repair failed waterproofing or leaking plumbing behind the tiles.
Check whether grout repair is suitable
Remove and replace grout that is cracked, loose or missing. Sealing over damaged or contaminated grout will not provide a durable repair.
A local repair may be suitable when the damage is isolated and there are no signs of a concealed leak. Arrange professional assessment if:
- cracks return after repair
- tiles are loose or damage affects several areas
- dampness persists after the shower has dried
- water, swelling or stains appear outside the shower.
Wall-to-wall and wall-to-floor junctions generally require flexible sanitary sealant rather than rigid grout because these surfaces can move independently. Grout sealer will not repair failed flexible sealant or the waterproofing system behind the tiles.
If water is near electrical fittings, stop using the shower and do not touch wet electrical equipment. Arrange urgent professional help.
Repair and seal the grout
Dry and prepare the area: Keep the shower out of use, ventilate the room and let the joints dry completely. Wear gloves and eye protection, and follow all product labels.
Remove damaged grout carefully: Use a hand grout-removal tool to remove loose and cracked material to the depth required by the replacement-grout manufacturer. Work carefully around tile edges. Stop if you risk damaging tiles, the substrate or concealed waterproofing.
Clean the joints: Vacuum out dust and fragments. Remove soap, oils and other contamination with a cleaner confirmed as compatible with the tiles and grout, then let the joints dry fully.
Regrout the shower tiles: Apply a shower-suitable grout according to its manufacturer’s instructions. Pack the prepared joints firmly, shape them and remove excess grout without washing material out of the joints.
Allow the grout to cure: Keep it dry for the manufacturer’s stated curing period. Do not rely on a generic waiting time, as requirements vary between products and conditions.
Check whether sealer is required: Many cement-based grouts require a compatible penetrating sealer, while epoxy and some proprietary grouts may not. Check the current instructions for both the grout and sealer.
Seal the cured grout: Apply the sealer evenly as directed, avoid flexible sealant and promptly remove residue from tile faces. Apply further coats if specified and wait for the labelled drying or curing period before using the shower.
What affects regrouting cost?
There is no reliable standard price. The quote depends on the extent and depth of damaged grout, tile condition, access, preparation, products, labour, location, current market conditions and whether the underlying cause is a plumbing, waterproofing or substrate defect. An appropriate professional should inspect the shower and quote the confirmed scope.
When sealer will not stop the leak
Grout and sealer are not the shower’s primary waterproofing system. They cannot repair leaking pipes, taps, wastes, failed junctions or a damaged waterproofing membrane.
If leaking continues after the grout has fully cured, stop surface repairs. Do not remove tiles or attempt concealed plumbing or membrane work yourself. Our Sydney leaking-shower plumbers can assess whether the leak is plumbing-related or requires another appropriately qualified trade.