Restraint Straps

Heavy duty straps are designed for lateral (horizontal) restraint — they resist wind loads trying to push the roof sideways. They're made from hot-dipped galvanised steel and are typically thicker. Light duty straps are for vertical restraint — they stop the roof from lifting off in high winds. They're made from pre-galvanised steel and must be at least 900mm long. Both are required by UK Building Regulations (Approved Document A).

Building Regulations require restraint straps at no more than 2 metre centres along all walls supporting the roof. Measure your wall length, divide by 2, and round up. For example, a 10-metre wall would need a minimum of 5 straps. Always consult your Building Control officer for site-specific requirements — some designs may need closer spacing.

The bend or twist is where the strap changes direction — one end is fixed flat to the timber trusses/joists, and the other end bends 90° (or twists) to go down or into the masonry wall. The standard options are 100mm or 150mm from the end of the strap, which determines how much of the strap sits on the timber before it turns into the wall. We can manufacture custom bend dimensions on request.

For fixing to timber, use suitable wood screws or nails through all pre-drilled holes. For masonry fixing, use hardened nails (for direct fixing into mortar joints or blocks) or wood screws with wall plugs. The lowest masonry fixing on light duty vertical straps should be no more than 150mm from the bottom of the strap. Always follow your structural engineer's specification.

Yes — as standard we manufacture in 100mm increments starting from 300mm, but we can produce custom lengths and alternative bend or twist dimensions to your exact specification. Contact our team on 0116 231 2984 with your requirements and we'll provide a quote. Lead times for custom orders are typically 5–10 working days.