The membrane is.
Why do you put rocks on a flat roof.
When you should not choose a tar gravel roof.
The gravel can be applied in far less time than using a specially.
The purpose of gravel on a flat roof.
Specifically there are two main reasons to use a ballasted roof system.
The rolls are cut to fit then unrolled across the roof and smoothed out to avoid air bubbles.
This is still the case for the primary or base roof.
Ideally the stones are river gravel which has smooth edges and won t cut into the roof when somebody walks around on it.
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.
For many years the only way you could cover a flat roof was with rolled rubber roofing.
I assume you re not talking about rocks meaning boulders but rather the layer of small stones you see not just on gas stations but on many flat roofs.
Gravel is used on flat roofs for two reasons.
Do not apply fabric membrane to a gravel 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.
Why do they put gravel on flat roofs.
Both factors can extend the life of your flat roof.
This is costly and guaranteed to fail unless surface has been filled and smoothed.
These roofs are installed as thin sheet materials 0 030 30 mils to 0 060 inches 60 mils thick and are applied to the roof in a single layer.
Avoid applying coating to roofs that need repairs fix these first.
So all you need to be able to say to your roof contractor is you want an epdm rubber roof.
Do not apply coating to a badly worn or dried out roof.
Have you ever wondered why contractors install gravel on flat roofs.