Reseal the shower or the whole bathroom?

Map the actual separation

Dry each run and shine a light along the edge. If other junctions remain bonded, limit the work to the affected joint. Replace the continuous run rather than laying a patch over old silicone.

Where the detail calls for sanitary silicone on two compatible surfaces, consider OTTOSEAL S100. Porous stone needs a stone-compatible product.

If the sealant allows a Smoothing spray, use it sparingly when tooling silicone. Keep it off the bonding faces and check for staining before using it on stone.

If several joints fail on the same side

Check fixings, movement and compatibility before choosing a cartridge. S100 can suit compatible sanitary tile; natural stone needs a specifically suitable product. Correct a moving tray’s support before sealing.

If one edge is marble or natural stone, trial OTTOSEAL S70 on an offcut and check the tooling agent before touching the visible surface.

Dry-fit the FUGENFUX profiling tool. Choose the edge that meets both sides without scooping out the middle, then tool the bead before a skin forms.

Draw the repair limits

Mark the horizontal tray edge and the two verticals that meet it. Inspect behind the taps with a torch. Mark sound and detached sections and identify which discovery during removal would require extending the repair.

Before opening the cartridge, try the Presch silicone gun in the tightest corner. Check you can turn your wrist and release pressure at the end of the run.

Can I patch a two-centimetre gap?

Avoid sandwiching a new patch between old ends unless the system specifically allows it. Identify natural endpoints and redo the run on prepared surfaces.