Bituminous shingles calculator: roofing materials

What is a flexible shingle roof

Flexible shingles are bituminous strips nailed with roofing nails to a continuous OSB deck. An underlayment covers the whole slope, a reinforcing valley underlayment goes into valleys and abutments, and laps are sealed with bituminous mastic.

The calculator works out OSB boards, screws, underlayment, shingles and nails for the roof area, plus eaves and rake edges, hip and ridge shingles, roof vents and crew tools.

How consumption is calculated

Per 1 m² of slope — 1.05 m² of OSB-3 with 5% for cutting, 1.1 m² of underlayment with laps and 1.1 m² of shingles with 10% waste. Hip and complex roofs take 15% waste for shingles. Shingle nails — 35 per 1 m²: four per shingle, six in high-wind zones and on steep slopes.

Eaves, rakes, valleys, ridge and abutments are counted in running metres and depend on the roof shape rather than the slope area. They stay at zero in the request — enter the length manually.

Materials are the rate per 1 m² multiplied by the stage area. Tools are counted per crew unit and multiplied by the number of units.