Information
Fastening and anchoring
CETRIS is fixed with screws, rivets, staples or nails to timber or sheet metal — with corrosion-protected fasteners and pre-drilled holes.
All fasteners must be corrosion-protected (hot-dip galvanised or stainless). With ordinary screws, pre-drill holes to 1.2 × the screw diameter, and countersinking is recommended for the heads. Use screwdrivers with regulated speed.
- To timber: a self-tapping screw with double thread, hardened tip and countersunk head (CETRIS, Ø 4.2 mm, length 35/45/55 mm). At least 2/3 of the screw length should enter the timber. For floor boards, a screw 20 mm longer than the board thickness is enough.
- To sheet metal: self-tapping screw CETRIS 4.2 × 25 mm (threaded up to the head) or 4.2 × 35/45/55 mm. The screw should pass through the board by at least 10 mm.
- Facades: for screws or rivets up to Ø 5 mm, pre-drill the board to Ø 8 mm (boards up to 1,600 mm long) or Ø 10 mm (longer boards) so it can move. At least one fixed point with a Ø 5 mm hole is needed.
| Board 8 mm | 597 N |
|---|---|
| Board 10 mm | 788 N |
| Board 12 mm | 1305 N |
Screw and edge spacing depend on board thickness and the construction (e.g. a 12 mm board in an interior wall: screw spacing up to 200 mm; PD/PDB floor boards 16–24 mm: up to 300 mm). The exact fastening pattern and the assembly’s fire resistance are given per solution. Test: ČSN EN 320, screw CETRIS 4.2 × 35 mm, pre-drilled hole Ø 3.5 mm.