You might be able to keep the tiles
The neighbour downstairs sends a photo of a ceiling stain. You step onto the balcony and the tiles look fine. Before agreeing to a full strip-out, ask the contractor to explain how they will identify where the water enters and which parts of the floor they need to reach.
Retaining tiles may be practical if they are well bonded and a compatible system can connect to the drain, the wall edges and the sliding door threshold. Lifting some or all of the tiles may be necessary if the floor is loose, water is sitting underneath, the falls need rebuilding or the existing membrane needs replacement.
Check the drain, the door and the edges
A clean-looking tile field tells you little about what happens at its edges. Look from inside the doorway for water tracks, and tell the contractor where puddles remain after rain. If you can see the underside of the balcony or the room below, send photos that show where the stain sits in relation to the door and the outlet.
Ask whoever quotes the work to mark the proposed details for the outlet, the base of the walls and any railing fixings that penetrate the deck. Halo Shield’s terrace and balcony waterproofing service explains the scope to discuss for apartment balconies, villa terraces and roof gardens.
What an over-tile proposal should explain
Ask how the contractor will check whether the existing tiles are suitable for the proposed system. Then look at the finished floor level. A new layer can reduce the clearance below the door and change how the floor meets the outlet. The quote should explain how the new surface will drain and how you will use and maintain the finished balcony.
The Jumeirah terrace and balcony case study shows the difference between working on an open terrace and working in a narrow run alongside glazing. Use those photos to ask how your contractor will reach and protect the edges on your property.
If the tiles come up, who puts everything back?
Ask whether the quote includes lifting and disposal, repairs to the substrate, any corrections to falls, waterproofing, agreed testing, replacement tiles and reinstatement at the doorway. If a close tile match is important, agree the replacement finish before the existing floor comes out.
For an apartment, ask building management about contractor access and whether the unit below can be inspected. Confirm who will arrange any agreed water testing and when the balcony can reopen. Those arrangements can affect the programme just as much as the area of the floor.
If the leak is only at the sliding door
Water at the door might be entering at the threshold or frame, or it may be tracking there from the balcony. If the cause is unclear, start with leak detection and inspection before signing off on the floor work. Ask the inspector to show which parts of the deck, outlet and door junction they assessed and what they found.
For a useful quote, send photos of the whole balcony, the drain, the sliding door threshold and the stain below. Add the approximate area, the building or community and when you first noticed the leak.