Should you seal the joint yourself or call a professional?

Try the movement on a scrap

Turn a corner, release pressure and lift the nozzle without smearing the edge. Practise the whole sequence before buying material for the bathroom.

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.

Know the limits of your practice piece

Try a straight run, an inside corner and a joint between different materials. Record preparation, product and any failure after curing. Allow time for removal, cleaning and downtime. A neat test bead cannot prove the shower is watertight.

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.

Separate observations from assumptions

You can check whether paint on a skirting board is sound. You generally cannot see whether the membrane under a shower is intact. Think about the consequences of getting that second judgement wrong.

For a dry interior joint that will be painted, check the expected movement against the data sheet for OTTOSEAL A205. Try the finish with your actual paint.

Which job should I leave to a specialist?

A shower joint with signs of a leak needs the system checked. Practise on an accessible dry surface instead.