Gravel Porosity Blue Roof System

Ballast is a different style of gravel which is applied to single ply roofing systems.

Gravel porosity blue roof system.

On blue roofs water is temporarily detained on the roof surface using rooftop check dams or roof drain restrictors. By using the existing roof as a base the surecoat roof system can add an additional 10 20 years of life back into an existing gravel roof without tear off. Winds can tear roof coverings from roof decks and can separate roof decks from framing. Roof systems ranging from roof coverings to structural members typically fail when winds produce forces.

Additionally because a blue roof will involve water storage it is considered to be wet system so it is essential to confirm with manufacturers that their warranties. Section 4 6 3 9. Although the primary purpose of ballast is to weigh down the roofing materials it also offers similar protective benefits as described above. Verify that stone or gravel used for ballast within the stormwater storage area if proposed is specified on the plans as being uniformly graded clean washed stone either crushed or smooth and that it is noted.

An extensive green roof system installed atop the nyc department of parks and recreation s dpr five borough building on randall s island. Built up roofs or burs also called a tar and gravel roof is a well established and popular style of flat roof that is made up of alternating layers of roofing felt or fiberglass and asphalt that is applied with heat which combine to make a long lasting sturdy roofing system. The gravel embedded on the top coat of asphalt the flood coat. This modular system is one of six variations installed on the roof and covers 800 square feet con sisting of two foot by two foot trays with six inches of mineral soil and over 1 500 sedum plugs.

Gravel on a ballast roof system. The patented blue roof system utilises the roof construction for the attenuation of stormwater releasing it at a controlled rate in the period following the storm. Cavidrain building abg cavidrain drainage geocomposite is a preformed cavity drainage system designed to relieve water penetration from basements and buried structures. Materials chosen for insulation waterproofing and other roofing materials should have a long life expectancy.

Stone or gravel used for ballast within the. Blue roof systems are an effective practice for controlling runoff from buildings with flat or mildly sloped roof surfaces. If so the roofing design will specify its depth and porosity. Verify that a porosity of 0 40 is used for ballast stone.

A porosity of 0 40 must be used for ballast stone. F 12 blue roofs f 12 1 blue roof plan standards. Greater than the capacity provided by the elements of the roof system. When choosing the right gravel to combine with your sand for your road base refer to our technical specifications and avoid materials that solidify over time losing porosity.