Waterproofing is perhaps the most crucial step of renovating a bathroom. It is required to ensure that any water leaks are fully contained. If the waterproofing fails the damage can be severe and rectification involves stripping out your bathroom and starting over. We cannot over emphasise the importance of this step so please make sure you either do it properly or get a professional waterproofer to do it for you.
If you decide to do it yourself you will need the following:
- Water Based Polyurethane Waterproofing
Clean up all floors and walls and make sure there is no dust. Prime all the walls. To ensure that the waterproofing bonds correctly to the surface. Give the primer ample time to dry then using Sikaflex or a polyurethane sealant proceed to seal all joints and perimeters. This means between the wall and floor, wall edges, and around tap holes. If you want to take an extra step to help waterproof I like to apply a fibreglass sheet on top of the Sikaflex. This way we have 2 bond breakers if one ever fails (very unlikely, but always better safe than sorry).
Next you need to measure out your shower area and place your angles down accordingly. Angles are bonded to the floor by applying the Sikaflex sealant underneath. Make sure your angle is 100% level as the tiling follows this level. You also want to install the door stopper angle to prevent water from escaping your bathroom. This is applied the same way. You want to make sure that both the shower angle and door angle are level with each other.
Once these are complete start by brushing on the waterproofing around all perimeters. You need to go up by approx. 150mm around all walls. In the shower wall we always recommend passing the shower head height so approx. 1800mm high. A crucial aspect you shouldn’t miss is waterproofing into the drains. This is the number 1 cause of leaks if not done correctly. Make sure you apply the waterproof generously and go down approx. 100mm into the drain. Once this is complete proceed to roll on the rest of the floor area and complete shower walls.
Give the waterproofing 24 to 48 hours to cure. Then repeat the process and apply a second coat. You will not need to repeat the Sikaflex and fibreglass with this step. Again we stress that the waterproofing stage of a bathroom renovation is not only the most crucial but also the most common error made in DIY bathroom projects. Near enough is simply not good enough for this step. It HAS to be 100% correct.