roof

A roof is the upper covering of a building. It provides weather protection, helps regulate indoor temperatures, and transfers loads from the structure to the walls or frame. By directing rain, snow, and wind away from the interior, a roof also acts as a barrier against moisture and debris.

Key components include the roof deck, underlayment, the roof covering (such as shingles, tiles, metal panels, or membranes), flashing at joints and penetrations, vents for moisture and heat management, insulation, and a drainage system with gutters and downspouts. Ventilation and vapor control help prevent condensation within the attic or roof space.

Roofs vary in shape and material. Common roof forms include pitched forms such as gable, hip, and shed, as well as flat or low-slope designs. Common coverings include asphalt shingles, concrete or clay tiles, metal panels, wood shingles or shakes, slate, and single-ply membranes.

Design and construction must consider loads, climate, and drainage. The roof structure may use rafters and joists or prefabricated trusses. Slope affects drainage and wind resistance; higher pitches shed water more quickly but may be harder to construct. Insulation and ventilation influence energy efficiency and moisture control.

Maintenance involves regular inspections for damage, sealing leaks, replacing worn shingles or tiles, maintaining flashing, and keeping gutters clear of debris. Lifespans vary by material—roughly 15–30 years for asphalt shingles, several decades for metal and tile, and much longer for slate—subject to climate and maintenance.