Over the past few years it has been a growing trend to see windows in showers.
I am not sure if our inhibitions are lessening or there is a practical application for this such as better air flow to the room, or is it we are designing more narrow lot homes and we need all the available wall space for natural light and ventilation. I suspect there is a little of each in this trend.
But with this trend there are some underlying building issues that need to be considered so as to avoid long term pain and costly rectification.
The first is the position of the window. We have recently installed a window that takes up the full wall of the shower.
Large windows like this pose a real problem in the life of the shower. The reason being is that the entire enclosure of the shower needs to be waterproofed. To do this there are a number of products on the market that are suitable, however, due to the size of this window and the fact that it is from floor to ceiling, it is actually acting as an articulation joint for the building. What does that mean? An articulation joint accommodates movement in a building and we are by nature encouraging the building to move on the line of the window reveals.
Now in normal construction this is not a problem, however, when we are waterproofing the entire area and then tiling, it becomes a big problem.
Why I hear you ask?
When the building moves it is going to want to rip the water proofing membrane and as a result cause the shower to leak and this causes the structural elements to deteriorate (eg., timber). The second and more visible effect is that the movement could cause the tiles on the walls to crack. Pretty unsightly and not the intended finish to the area.
Shouldn’t there be a product that can withstand the movement of the building? Yes.
There are polyurethane products that are strong but also extremely flexible and will more than likely withstand the movement in the building. However (there is a down side), tile adhesives have problems sticking to windows. In fact from my experience I have not yet been able to find a tile adhesive manufacturer that will warranty their product on polyurethane. So we might have fixed the issue of tearing the membrane but we have now created a possible issue of drummy tiles that end up popping off the membrane and looking ugly to boot.
What is the solution I hear you ask?
- Move the window up above the spray line of the shower head, that way we don’t have any issue with the waterproofing at all and we can use appropriate products to avoid the tile glue issue.
- If we turn the window horizontally (i.e., have a long but narrow window) then we reduce the movement in the building thus avoiding issues with cracking and tearing of the waterproofing.
I am not opposed to stretching building conventions but some things are not meant to be and there are long term issues that may occur particularly if the house is on a reactive soil site.
You might say, “But I have seen it done before”, and I would say that just because it is happening doesn’t make it a good thing. It just means that not enough people have been stung. A bit like building homes with asbestos cement, a lot were using it prior to 1980 but we now know its damage.