Attic joists that are made from 2x8s may be acceptable for building your attic floor but because every room is variable there are no absolutes.
Attic floor stilts.
Standard joist spacing for the installation of attic flooring materials is 16 inches on center oc meaning the distance from the center of one joist to the center of the next joist is 16 inches.
Loft storage stilts are used for creating a raised storage area inside a loft whilst not compromising on thermal efficiency.
Joist dimensions are only part of the equation.
Easy to fix down on the joists and easy to attach the loft board to.
Attic dek panels require no measuring or cutting.
Even those with little diy skills or time can now easily elevate the boarded section so that their loft can be used for storage whilst still having 270mm of loft insulation.
Attic joists for live loads.
Diall loft storage stilts have been specifically designed to create a raised boarded area inside a loft.
The stilts lift the loft boards the extra height to enable the loft insulation to remain in place and not compress it putting pressure on the ceiling.