What are parapet walls? A comprehensive guide to understanding
Parapets are short walls above a rooftop. There are a few good reasons why parapets walls are used. The roof membrane generally is required to be installed up the parapet wall and often terminsted with a roof coping. There are a few good reasons why parapets walls are used.
1. Terminination of the roof membrane. A parapet allows the membrane to terminate under a coping which, in most cases, spans the top of the parapet wall and extends the each side of the parapet.
2. Flat visual wall line. Roof membranes are generally built so that they have a gradual or slight slope. That slight slope islope is generally more than 1/4 inch per linear foot. Over a large spin that gives the rooftop a slanted appearance. The appearance. The parapet though, on the other hand, can be built so that it is flat and when you look at the building from the groun instead of seeing the roof itself, you see the exterior wall with a flat top. Generally people consider a flat wall to look better than a wall with a slightly slanted top.
A picture of a roof parapet, shown from the roof side, follows below.
Anyone can see the opposite side of that same parapet from the ground. Normally though, most people, who can only see it from the exterior side would think it just as the wall itself, not an actual parapet. From the roof though, you can see the wall just extends so many inches above the roof
In the picture below we show the same rooftop and parapet wall but at the rear termination. The rear termination of the roof is generally built with a drip edge fed into a gutter which channels water into a downspout and away from the building. This particular photo shows a building that is clad with cementitious siding. In this case the cementitious siding was installed thoroughly incorrectly by other contractors before our company was involved to make repairs.
