The waterproofing industry at the moment is unregulated, with a lot of companies not even being qualified waterproofers. Home owners need to ask a few question before engaging with a so-called expert to waterproof their shower.
What is their track record and what qualifications do they hold?
A plumber is not a licensed waterproofer. They are both completely different trades, just like a mechanic is not a licensed builder.
What materials do they use?
Most remove the existing grout and replace it with an epoxy grout. Epoxy grouts were mainly developed for commercial kitchens to stop fats and grime penetrating the grout and causing health issues. When used as intended they do not absorb water and are extremely rigid and therefore durable. All buildings move and without a flexible seal, cracks develop in the grout and the shower starts leaking again.
What processes do they employ?
Then there are companies who remove all the tiles at the base and one or two rows around the perimeter. They waterproof the base and the wall by replacing the original membrane and retile this area. By cutting away the original membrane there is now a weak point for the water to get through, at the join. They could try to overlap the two membranes but most don’t as the tiles won’t lay flat across the overlap. So, what happens if water leaks between the tiles and the membrane above the join? It seeps through the join and creates more problems.
Am I covered for any damaged caused by their process?
Removing tiles creates problems of its own. If a tile is broken very rarely can you find another one to match and quite often the shower screen has to be removed. Removing the shower screen is time consuming and creates a risk of damaging it or the surrounding tiles. More cost for the owner of the dwelling.
Do I get any sort of guarantee and what is covered?
Most of these companies offer a 12 year to 25 year material warranty, with no mention of labour. If you have an issue and its starts leaking again you may end up paying for the labour which in most cases is the biggest part of the expense.