Roofing Glossary

Actual cash value is an insurance valuation that generally accounts for depreciation from age, condition, or wear.

A bent metal flashing installed along eaves and rakes that directs water away from the fascia and protects the edge of the roof deck.

Ethylene propylene diene monomer: a synthetic rubber single-ply membrane, traditionally black, with seams joined by tape or adhesive.

The vertical board or trim running along the lower edge of the roof, where gutters are typically attached.

Thin, water-resistant material, usually metal, installed at joints, intersections and penetrations to direct water away from vulnerable areas of the roof.

Replacement cost value is the estimated cost to replace damaged property with comparable new property before depreciation is applied.

An exhaust vent installed along the roof ridge that lets warm, moist air escape from the attic.

The steepness of a roof, usually expressed as inches of vertical rise per 12 inches of horizontal run, such as 6:12.

The finished underside of the roof overhang, between the fascia and the exterior wall. It often contains intake vents for attic ventilation.

A unit of roof area equal to 100 square feet, used to measure roofs and order materials.

A metal roof system with raised, interlocking seams between panels and hidden fasteners.

Thermoplastic polyolefin: a single-ply membrane, usually white, with heat-welded seams, widely used on commercial low-slope roofs.

A water-resistant layer installed over the roof deck and beneath the roof covering. It gives secondary protection against water that gets past the primary roofing material.