Why Are Rocks Put On Flat Roofs

For mineral based felting the pebbles are there to help protect the felting as ballast depending on the fitting type and to help prevent water pooling aparantly.

Why are rocks put on flat roofs.

This appears to be a form of roof ballast. Epdm and neoprene roof seams are fastened by adhesive and pvc roof seams are heat or solvent welded. Specifically there are two main reasons to use a ballasted roof system. Talk to ten roofing contractors and you ll get ten answers on what the gravel is for but this seems to be the consensus.

They can be partially loose laid and held down with river rock ballast requires roof structure to support the weight or fully adhered to the roof deck. A layer of pebbles can substantially extend the life of a flat roof. Admittedly one that i have not seen but i haven t been in the desert since i was a kid. Rocks are placed on commercial flat roofs for many different reasons if the roof is what is called a ballast roof it is not fastened or adhered down throughout the whole roof.

Flat roofs are an ancient form mostly used in arid climates and allow the roof space to be used as a living space or a living roof flat roofs or low slope roofs are also commonly found on commercial. A flat roof will have several layers of a thin membrane made of tar asphalt and or bitumen material. In a typical tar and gravel roof which by the way is gradually being supplanted by gravelless roof systems you put down a layer of tar paper then tar and finally gravel. Simply put it is a flat roof with a slight pitch so water can run off it.

Personally i dislike them. Pebbles or small rocks spread several inches thick over the outer roof mem. The membrane is. Tar has a low melting point.

You can still find houses here in the city with rock roofs. Roofing ballast is usually the little pebbles you see on a flat ish roof. The weight provided by the gravel is used to anchor down the roof materials therefore using far fewer fasteners to hold the materials to the decking. March 11th 2010 at 2 41 pm.

Membrane roofs are attached in a variety of ways. Both factors can extend the life of your flat roof. We had to replace a big portion of our flat roof recently. There are no angles ridges or gables to deal with.

A flat roof is a roof which is almost level in contrast to the many types of sloped roofs the slope of a roof is properly known as its pitch and flat roofs have up to approximately 10.