A Roofing Terms Glossary for Property Claims

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Roofing terminology appears throughout property claims, and a policyholder encountering it for the first time can find the vocabulary as confusing as the damage itself. Decking, sometimes called sheathing, refers to the structural panels, typically plywood or oriented strand board in most Midwest construction, fastened to the roof trusses or rafters that everything else on the roof is built upon. Underlayment is the layer installed directly over the decking and beneath the shingles, traditionally asphalt-saturated felt paper, though synthetic underlayment products have become common in recent years for their improved tear resistance and water shedding. Both types serve the same basic purpose of providing a secondary water barrier beneath the shingle layer in case wind-driven rain or ice works its way past the primary roofing surface.

Ice and water shield is a self-adhering waterproof membrane required by code in many cold-climate jurisdictions, including throughout Minnesota, installed along eaves, valleys, and around penetrations such as chimneys and skylights to guard against damage from ice dams, which form when melting snow refreezes at a roof’s edge and backs water up under the shingles. Drip edge is the metal flashing installed along the eaves and rakes, the sloped edges of a roof, that directs water away from the fascia and into the gutter system rather than allowing it to run down the side of the building.

Flashing broadly describes the metal components installed at any point where the roof plane meets a vertical surface or a penetration, including step flashing along a chimney or wall, and counter-flashing that overlaps it to shed water. Valleys are the internal angles formed where two roof slopes meet and funnel water downward, and they are frequently a point of both actual damage and disputed damage assessment, since valley materials and installation methods vary and are more exposed to water volume than open field shingle areas.

Granule loss refers to the surface material embedded in asphalt shingles being dislodged, commonly from hail impact, foot traffic, or simple aging, and it is a central point of evaluation in hail damage assessment, since granule loss exposes the underlying asphalt mat to accelerated weathering. Inspectors often distinguish between granule loss caused by hail impact, which typically appears as a random pattern of bruised or fractured spots, and granule loss from ordinary aging, which tends to appear as a more uniform wearing across the entire roof surface. A starter strip is the first course of shingles installed along the eave, specifically designed to provide a sealed edge beneath the first visible course, and ridge cap refers to the shaped shingles or metal pieces installed along the roof’s peak to cover the seam where two slopes meet at the top.

Ventilation terms come up often as well, particularly ridge vent, a continuous vent installed along the peak, and soffit vent, installed under the eave overhang, which work together to allow air to flow through the attic space and reduce the moisture buildup and ice dam formation that cold-climate roofs are especially prone to. Matching refers to the question of whether replacement materials, such as shingles on an undamaged portion of roof adjoining a damaged section, need to match in appearance, a topic governed by policy language and state regulation rather than by roofing terminology itself, and therefore a coverage question outside an appraiser’s role.

The material above is general education about how property insurance appraisal commonly works, not legal advice; specific procedures differ by state and policy.

Russ Lis works nationwide as a property insurance appraiser and umpire, based in Minnesota. Contact Appraisal Resolution.