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.
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.
The membrane is.
In my last place the flat roof was covered with small stones which was better on.
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.
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.
But such a low slope holds snow and water much longer than a steeply pitched roof and therefore needs a very different material to stay watertight.
Flat roofs usually come with a 10 to 20 year warranty but can last 25 years if you build the roofs right and maintain them using commonsense rules.
To protect the underlying layer of roofing materials as is the case with built up roofs burs.
All the suspect areas have a third layer of felt also.
On many flat roof low slope commercial buildings it s common to see gravel on top of the roof.
Flat roofing is not actually flat.
Built up roof bur the traditional hot tar and gravel.
The extension is directly beneath the back windows so looks un sightly.
Membrane roofs are attached in a variety of ways.
To weigh down or secure the.
Specifically there are two main reasons to use a ballasted roof system.
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.
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.
It has a very low slope between 1 4 to 1 2 inch per foot so that it drains water.
Gravel is used on flat roofs for two reasons.
Epdm and neoprene roof seams are fastened by adhesive and pvc roof seams are heat or solvent welded.
It has a layer of undercoat and then a layer of the self adhensive felt on the top.
Have you ever wondered why contractors install gravel on flat roofs.
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.