Correct waterproofing application, in accordance with manufacturers recommendations, in wet areas is absolutely critical – water ingress into floor and wall cavities can very easily compromise structural timbers, gyprock, timber skirting, carpets etc, leading to an expensive experience to correctly rectify. The most awful aspect concerning this scenario, is that the homeowner/occupant won’t normally realise a leak exists, until the worst of the damage has becomes physically evident.
Associated damage from either incorrectly installed waterproofing, or third party damage, has been anenormous issue in Western Australia, witnessed by by self (in the capacity of an applicator) over the past 25yrs. To combat the historical issues, there have been changes to waterproofing requirements for ‘wet areas’ in recent years, through amendments to the B.C.A, & more comprehensive instruction from suppliers, thanks to social media.
Generally, in W.A, waterproofing to ‘wet areas’ involves applying a liquid membrane, either a class 2 or 3, onto substrates that are expected to see water, returning the membrane at the wall/floor junction, so as to create a kind of ‘tanked’ area. Obviously the resolve is to help contain any water that might find its way out, perhaps through failed grouting or joins, or structural movement.
The first, most important scope when waterproofing a ‘wet area’, is to inspect & assess the substrate, to identify the most appropriate PRIMING agent. Without the correct primer, the job is already compromised. Once thoroughly cleaned out & primed, the perimeters & right angles need to first be sealed using a ‘neutral cure’ silicon which will adhere tenaciously to the substrate.
Likewise, a ‘polyfab’ bandage (abbreviation for ‘polyester fabric’) can also be used over these joins to create what’s called a ‘bond breaker’. The bond breaker is slightly elastomeric, assisting to decouple the waterproofing membrane at the joins, allowing forminor movements in the building structure over time, of which won’t compromise the membranes integrity. A bead of silicone is also beneficial around penetrations through the waterproofing membrane – like tap outlets and drains.
The waterproofing membrane is applied first, then thepolyfab bandage is ‘imbedded’ into the membrane to ensure that it’s fully soaked through, and to make sure it properly adheres to the wall or floor junction. The membrane is then painted across walls and floors using a brush & roller. Typically two coats will be applied (to reach a dry film thickness, as specified by the Supplier), the second one rolled at right angles to the first (i.e. if the first coat is rolled vertically, second coat rolled horizontally).
It’s important to respect that there are specific waiting times for the waterproofing membrane to dry & cure, prior to tiling, in accordance with chemical engineering, post final coat. A very common mistake in the WA building industry is the failure to WAIT the minimum time the Supplier recommends, especially in winter, when the cooler temps,& lower humidity retards the curing process, prior to tiling.