Loft Boarding Cost Calculator

About this calculator

Boarding out a loft floor means covering the joists with chipboard or OSB panels to create usable storage space, and the material need is simply the attic floor area divided by the coverage area of one board, rounded up and increased by a waste allowance — typically around 10% — to account for cuts, offcuts and boards lost to fitting around obstructions like the water tank or roof timbers. Cost is then that board count multiplied by the price per board, plus fixings.

UK homeowners planning a loft boarding project use this calculation to get an accurate materials budget before ordering, since underestimating boards means a second trip to the merchant mid-job and overestimating ties up money in boards that never get used — and the waste allowance matters more than people expect once real joist spacing and obstructions are factored in.

This calculator takes your attic floor area, board size and price and returns the number of boards needed and the total material cost including waste allowance, so you can budget the project accurately before you start.