The tiles around our bathtub are bulging and coming loose from the walls on all three sides of the tub enclosure. And I can’t seem to control the mould that keeps re-appearing along the base of the tiles where they join the tub. Is there any product or quick fix solution to remedy the loose tiles and mould?

From your description of the problem, it seems that moisture from showers and water splashes from the tub have soaked through the ceramic tiles. When this happens, the water swells the substrate to which the tiles are attached. Often, in older homes, trades people and homeowners installed conventional drywall or plywood as a substrate behind tiles. Unfortunately, these materials are not impervious to moisture. To make the situation worse, most folks forget to re-seal the ceramic tile grout on a semi-annual basis. So, moisture continuously wicks through the grout to the wood or drywall “sponge”. Inevitably and eventually, the mortar that binds the ceramic tiles to the substrate fails from constant wetting and drying.

Unfortunately, I don’t know of any quick fix for this problem. In my opinion, the most permanent solution is to remove all the tiles: then remove all the substrate. You will probably find some rotting wood  somewhere in this assembly, so check the sub floor under the bathtub as well as the fall sheathing and framing materials.

After the demolition and repairs, I recommend that you install “aqua board” or “wonder board” as a substrate for the new ceramic tiles. Aqua board is a gypsum-based (drywall) product that is water resistant .Wonder board is a cement-based concrete fibre board. Although it is a little harder to cut and fit, I prefer the wonder board because unlike the paper finish on aqua board, it seems less likely to absorb moisture. Don’t forget to thoroughly seal the new tile grout and re-seal it on a semi-annual basis.