Silicone resealing: the ninety-minute job everyone quotes at thirty
Blackened silicone around a shower tray or kitchen sink is probably the most common small job in UAE bathrooms, and it is also the most commonly botched, because the visible part (running a new bead) is the quick part. The job is really a removal job. Every trace of the old sealant has to come out: cut free with a blade, scraped, then the residue dissolved or abraded away, because new silicone will not bond to old silicone and any mould left in the joint grows straight through the fresh bead within months.
The surface then has to be genuinely dry, not towel-dry but dry-dry, which in a family bathroom means the shower is out of use for a few hours before the work, worth knowing when you schedule the visit. The pro then masks both sides of the joint with tape, guns a sanitary-grade anti-fungal silicone (not general-purpose acrylic, which is cheaper and fails fast in wet areas), tools the bead smooth in one pass, and pulls the tape while the bead is wet, leaving those crisp straight edges that separate professional work from a DIY afternoon.