Waterproofing At The Top - Roof Waterproofing

It’s time to talk about waterproofing at the top of it all. Waterproofing on roofs. These days, roofing systems and roofs in designs are becoming more and more popular as we have more highly dense cities and apartment living and apartment building.

Even people that have got two story homes are utilizing those external areas and are turning them into functional roof areas that they can either have as part of a feature or use like a garden area or an entertainment area.

Let's think about the apartment building.

The fact is that if you've got a roof garden or a ballast type of roof, these roofs will hold. When it rains, and it rains a lot more than what you're going to have in a bathroom, the water will sit there. Depending on the drainage design, even with good drainage, you've got a lot of water. That can take a while for it to actually soak through. It's after the rains, there's a retention of water in the garden area or on the ballast that's just soaking through. You've got demands of varying temperatures out there, movement of the building structure itself, and a volume of water. If it's a roof garden area, you've also got potentially a planter box garden area where there are roots of plants, et cetera, that could impact the waterproofing membrane.

You need to understand the properties of the waterproofing membrane you require, and there are some spray on liquid systems that can be used. Many of you argue that you can't, but there are some of these high tech durable coatings that can be used in roof areas that are like garden areas, et cetera. If you've got them where you've actually got a lot more abrasion that's going to happen on top of the membrane, either during the installation of the roof garden or at the time with the ballast rocks et cetera, then you may be going with a waterproofing sheet system, such as the Gripset GC Sheet Range, that has a high level of durability.

Whatever you are dealing with there, the critical functions, the wall-floor junctions, it doesn't stop with a standard bond breaker. You need to integrate your waterproofing membrane up the parapet. There are a lot of areas of water entry, and you need to nail all those.

The other part is the drains. The drainage detail is so critical, so don't just start waterproofing. You need to understand that the drainage area is functional for the area that's going to be exposed to what the roof is designed for. If it's a roof garden, ballast, or just getting weather.

Obviously, you check your folds, whether you need to integrate that in before or after your waterproofing membrane system. My view on a roof area like that, always best to have it before you put your membrane down and then get your floor or whatever that system is on top, be it the garden area or a ballast that goes on top of that waterproofing membrane. Understand where the potential stresses are on the waterproofing membrane, because at the end of the day, when it's covered with the roof garden or a ballast, it is going to be exposed to a lot of different pressures. What you have as well is that where there's moisture building up on top of the membrane surface, with those temperatures that change out there, it can create all types of stresses on that membrane, a lot more than what you may be used to for if you're dealing with balconies and decks where they're tiled over.

If you need more advice on this, check in with our Tech Service department on 1800 650 435 or email techenquiries@gripset.com