Why Do People Put River Rocks On Flat Roofs

If there is a complete covering of the roof with small rocks gravel then it is the top layer of a built up flat roof.

Why do people put river rocks on flat roofs.

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. It has a layer of undercoat and then a layer of the self adhensive felt on the top. To protect the underlying layer of roofing materials as is the case with built up roofs burs. Talk to ten roofing contractors and you ll get ten answers on what the gravel is for but this seems to be the consensus.

All three types of flat roofing cost 250 to 350 per square 100 square feet but prices vary according to region and size of the roof. It has a very low slope between 1 4 to 1 2 inch per foot so that it drains water. Specifically there are two main reasons to use a ballasted roof system. Built up roof bur the traditional hot tar and gravel.

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. Flat roofing is not actually flat. I have just had a flat roof put in on an extension. 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.

To weigh down or secure the. The extension is directly beneath the back windows so looks un sightly. Both factors can extend the life of your flat roof. Have you ever wondered why contractors install gravel on flat roofs.

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. On many flat roof low slope commercial buildings it s common to see gravel on top of the roof. Gravel is used on flat roofs for two reasons. In my last place the flat roof was covered with small stones which was better on.

All the suspect areas have a third layer of felt also. Membrane roofs are attached in a variety of ways. The membrane is. This protects the other layers from damage by hail or storms also people walking on the roof so they do not damage the waterproof layers below.

Tar has a low melting point.