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Glossary

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Term Description
Built-up roof (BUR) A continuous, semi-flexible roof membrane consisting of multiple plies of saturated felts, coated felts, fabrics or mats assembled in place with alternate layers of bitumen and surfaced with mineral aggregate, bituminous materials, a liquid-applied coating or a granule-surfaced cap sheet.
Overburden Any material installed on top of a waterproofing assembly.
Overburden dividers Overburden dividers include gravel boards, edge pieces, rounded edge sections and vegetative roof system edge definers. They are used to separate overburden types, such as growth medium and pavers or growth medium and rock; they are installed over the protection course, drainage layer and filter layer and can be polyethylene (vertical piece with support stands) or stainless steel (L-shaped). Overburden dividers are not mechanically fastened but are loose-laid and ballasted and typically have drainage slots. They are installed over the protection course, drainage layer and filter layer and should be secured to avoid displacement.
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