Gravel is an excellent fire retardant.
Why is gravel on roofs.
Tar and gravel roofs add substantially more weight to the building structure.
What is a built up roof bur.
Gravel is used on flat roofs for two reasons.
Gravel roof disadvantages on the other hand gravel roofs are hot energy inefficient heavy moisture trapping and unstable.
A flat roof typically has a rubber or asphalt impregnated membrane.
It is made up of alternating layers of roofing felt or fiberglass and asphalt that is applied with heat.
Built up roofs or burs also called a tar and gravel roof are a style of flat roof.
To weigh down or secure the roofing material as is the case with single ply flat roofs.
It provides excellent protection against uv rays and is an attractive option for windows and decks that overlook the roof.
Now that you know why gravel roofing is often a preferred choice we will now move onto what a bur roof is.
After you add the layers of tar supporting fabrics and the top layer of gravel your roof can be an extra 5 10 lbs.
Built up roofing bur was the most common type of flat roof before modified bitumen and membrane roofing were developed.
Gravel roof advantages most gravel roofs are inexpensive to build offer some protection to vulnerable asphalt against uv damage and the stones are very durable.
Therefore you can save money in the long run.
Have you ever wondered why contractors install gravel on flat roofs.
These materials provide the waterproof barrier that contains and sheds the water to protect the roof structure.
Tar and gravel flat roofs are one of the most cost effective roofing solutions.
Of all the flat roofing options a tar and gravel roof is the most economical.
To protect the underlying layer of roofing materials as is the case with built up roofs burs.
A tar and gravel roof has a life expectancy of about 20 to 25 years.
Advantages of a tar and gravel roof.
Tar has a low melting point.
Talk to ten roofing contractors and you ll get ten answers on what the gravel is for but this seems to be the consensus.
However both rubber and asphalt will lose plasticizers and other v.
Per square in heavier than before.
Contractors and builders use gravel on flat roofing for two primary reasons.
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.
Bur consists of many layers.
The first is to protect the underlying layer of roofing materials on built up roofs burs and the second is to secure or weigh down the roofing material as is the case with single ply flat roofs.
Top problems with tar and gravel commercial roofs added weight to structure.