Restraint Straps and Banding
- Light and Heavy Duty Restraint Straps,
- Edge Rolled Restraint Straps,
- Timber Frame Straps,
- Fixing Bands
The trussed rafter roofs and traditional cut roofs should be supported on timber wall plates. For trussed rafter roofs not subject to uplift, the minimum fixing should be two 4.5mm x 100mm long galvanized round wire nails, skew nailed, one from each side of the trussed rafter.
In situations where the roof is required to resist uplift, skew nailing is unlikely to provide sufficient strength. Appropriate metal restraint straps should be used. For dwellings of masonry construction,restraint should be provided at rafter level for gable walls. Larger gable or separating walls may also require restraint at ceiling level. Lateral restraint straps should have a minimum cross section of 30mm x 5mm and a minimum anchorage downturn of 100mm. Restraint Straps should be of sufficient length to be fixed to three trusses and should be fixed with solid blocking.
Restraint Straps shall be used to restrain gable and separating walls and hold down the roof against wind uplift. Restraint straps are required to provide stability to walls. They should be installed at not more than 2m centres for buildings up to three storeys (two storeys in Scotland). In higher buildings straps should be spaced at not more than 1.25m centres.
Restraint straps should be fixed to solid noggings with a minimum of four fixings of which one should be in the third rafter. The fixings should be four steel screws or four 75mm x 4mm (8 SWG) round nails. Rafters should not be notched to make the straps flush with the rafter. Straps should go under rafters and over ceiling joists. The turn-down should be on a substantial piece of blockwork, preferably the centre of an uncut block.
Restraint straps and banding is a set of high-quality products designed to reinforce connections between structural elements of a building, in horizontal, lateral and vertical restraints. Both light and heavy duty straps are produced from galvanised mild steel, and also from stainless steel.
Light Duty Restraint Straps are generally for vertical applications such as holding down the wall plate. Designed to The Building Regulations BS 5268 Part 3 and other building standards for vertical restraint.
Heavy Duty Restraint Straps are generally for horizontal applications providing lateral restraint of roof trusses, rafters and joists tied to masonry. Designed to The Building Regulations BS 5268 Part 3 and other building standards for lateral restraint.
Edge Rolled Restraint Straps are the more traditional strap produced from pre-galvanised mild steel, being the cheaper and lighter alternative to heavy duty straps. It performed equally or better in tests than the equivalent traditional 5mm Heavy Duty Strap, providing lateral restraint of roof trusses, rafter and joists tied to masonry.
The Timber Frame Strap is a holding down strap providing restraint against uplift to timber frames.
Fixing Bands are versatile multi purpose banding that can be cut, bent and formed for all types of light applications. Ideal for DIY, Industrial and Agricultural uses.
- Versatile coil strip for lightweight fixing applications,
- Suitable for timber and fencing repairs, clamping, bracing and restraining, pipe fixing, general support and ductwork etc,
- Manufactured from galvanised mild steel to BS EN 10327:2004 DX51D + Z275,
- Fix in place using screws, bolts,
- Can be easily cut using tin snips or shears.