Rigid / Continuous Insulation Board Count

Rigid continuous-insulation boards (XPS, polyiso, EPS) for an area, with waste and layers.

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Example

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Details, formula, and sources

boards = ceil(area x (1 + waste/100) / board area) x layers. A 1,600 sf wall in 4 x 8 boards at 8% waste is 54 boards a layer, so a two-layer continuous-insulation assembly with offset seams is 108 boards; a single layer is 54. The layer count, set by the required continuous-insulation R, is the multiplier; fasteners, plates, and tape are taken off separately. Distinct from spray-foam board feet and batt coverage.

boards = ceil(area_sf x (1 + waste_pct/100) / board_area_sf) x layers.

Rigid-insulation board-count identity by name (boards per layer from area over board area with waste, times the layers); first-principles arithmetic.

The board-count arithmetic is public first-principles; the continuous-insulation R and layers come from the energy code.

Estimate. AHJ and licensed professional govern.

Field names used by the API: area_sf, board_area_sf, layers, waste_pct, boards

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