Roof Ballast Depth

Additional benefits of ballast on a flat roof.

Roof ballast depth.

The depth of the ballast or media contained in the trays can be varied depending on the desire to reduce the presence of open water surfaces. The weight of the ballast equals the weight of the water it causes the vessel to displace. If you remove 64 1 pounds of ballast then the vessel will displace 1 cubic foot of water less than it did before the 64 1 pounds of ballast was removed. 1 a leak is very difficult to locate because the water runs freely in numerous directions and for longer distances under the loose laid membrane.

The heavier stones provide substantial protection against wind gusts. An insufficient depth of ballast causes overloading of the underlying soil and in unfavourable conditions overloading the soil causes the track to sink usually unevenly. Most roofers typically installed 10 15 pounds of ballast per square foot. Simply put a ballasted roof is easy to install and basically guaranteed maintenance work for a roofer.

Divide the amount of ballast to be added or removed by 64 1. To learn more about selecting a commercial roofer in cleveland ohio simply fill out the form on this page and a member of our team will be in touch. Though not as common as they used to be ballasted roof systems still prove to be a viable solution for today s commercial roof needs. Roofing southwest a ballast system helps cut roof system application costs as it takes less time to install since sealing the layers together isn t necessary.

Modular trays can have a variety of different outlet designs according to the goals of the installation e g reduce peak flows achieve specific lag time for target events etc. Stone ballast typically requires crushed graded stone placed over a stone filter sheet rolled out over the insulation. For built up roofing the gravel was generally 25 5 inches in diameter. Ballast is required with 20 lbs s f.

The gravel used in built up roofing what the roofing contractors were used to was not the same as that used in a ballasted roof. Needed at perimeters and at large penetrations. Ballasted roof systems are simultaneously a roofer s best friend and arch nemesis. Holes mean roof leaks and roof leaks mean call the roofer.

Doesn t produce any foul smell during construction. In the field of the roof a minimum of 10 lbs s f. Finally the ballast stone or and pavers are laid down throughout the roof system. Ballasted flat roofs are a popular choice especially for commercial buildings.

Generally loose laid ballasted roofing systems are not recommended or at least discouraged for three reasons. 2 the membranes tend to pull at their perimeter ties raising and stretching the. Benefits of a ballasted roof system. Installs very quickly since no fasteners or adhesives are used.

Ballast stones are usually one to two inches thick and applied more generously than on a built up roof. Seawater weighs 64 1 pounds per cubic foot. Somebody walking on the roof will undoubtedly step on the ballast and put a hole in the membrane. The stones used in ballasted roofing are generally 1 5 2 5 inches in diameter and applied in a thicker layer.