Processing information
Please note maximum breaking torque for each thread-Ø in respective DoP / ETA
For screw connections in load-bearing timber structures, installation specifications of ETA-12/0280 must be considered
Load-bearing, approval-relevant timber constructions to be calculated by structural engineer with ETA of applied screws
Fixing of thermal insulation must also comply with local applicable national regulations
Only countersunk head screws (Ø 6.0) allowed for connecting wood-based materials to roof-mounted insulation systems
To further increase load-bearing capacity, washers acc. to ETA-12/0280 may be used
For on-roof fastenings, screws have to be driven into the rafter in one sequence through battens and thermal insulation material without pre-drilling (ETA-12/0280: A.1.4. installation provisions)
Rafter width: min. 60 mm
screw/ center distance: max. 1750 mm
Insulation thickness: min. 300 mm
Compressive insulation strength: min. 0.05 N/mm²
Advice
Applicable with or without pre-drilling (pre-drilling-Ø ≤ screw core-Ø)
Pre-drilling usually not necessary for screwing into softwoods (e.g. spruce, pine, fir)
When using hardwood, pre-drilling is recommended to prevent screw breaks