(Ethylene Propylene Diene Monomer) is a membrane that is
essentially rubber with an additive to provide tensile strength. In the case of
black EPDM the major additive is carbon black. Black EPDM is one of the least
expensive roofing systems to manufacture and install, and as a result accounts for
one half of the single ply industry. The EPDM membrane is available in very large
sheets, therefore the quick covering of large roof areas is possible. EPDM membrane
is available in several thicknesses and optionally reinforced with a polyester
scrim. EPDM cures after weathering and requires cleaning and priming before repairs
There are numerous types of metal roof design and material
options, ranging from flat locked copper shingles, to steel Spanish-barrel tile, to
traditional standing or vertical seam, to aluminum and steel products designed to
mimic wood and tile shakes or shingles. Depending upon the individual product, metal
roofs can achieve a vast variety of looks, and can drastically differ in pricing, as
well. Generally, metal roofing products fit into two main categories: structural or
architectural. Structural panels, which are used on low pitch applications, are
usually installed directly over purlins, effectively becoming both the deck and the
roof, i.e. the roof structure. Vertical seam-type panels are the most common type of
structural metal roofing and are almost always used on non-residential projects.
Architectural metal roofing includes all specialty residential roofing products.
Generally, they are installed only on steeper pitched roofs (min. 3:12 in most
cases, to ensure proper water run off). Architectural panels are installed over a
wood or metal deck, or in some applications, directly over an existing roof.