Splicing Roof Trusses

Shop drawingdetailed drawings of a roof truss or roof framing showing critical.

Splicing roof trusses.

In light roof trusses entirely bolted connections are less favoured than welded connections due to the requirement for gusset plates and their increased fabrication costs. Rafter plates are almost always spliced due to the length of most structures. Ridge boards typically are one dimension larger than rafters a 2 by 6 inch ridge on 2 by 4 inch rafters for instance. If your roof rafter connectors will not be visible after your construction project is completed it may be possible to connect these rafters together using a rafter splicing technique you will want to check your local building codes before undertaking this type of construction as there are very specific ways that roof rafters can and cannot be spliced together.

The idea of trussed rafters arrived in this country from the states during the 1960 s and quickly became the standard method of constructing roof structures in domestic construction. It is stamped into the wood at the factory with a hydrolic press. Scab additional timber connected to a truss to effect a splice extension or general reinforcement. But sometimes a roof is too long for a single ridge board.

A gang nail is basically a thin piece of metal stamped out so that many metal tangs stick out into the wood about a 1 2 or so. Truss brace splicing methods he building component safety information bcsi booklet jointly produced by wtca and the truss plate institute recognizes three planes requiring restraint in a roof truss. Rafter plates are load bearing beams that support either a single rafter or a truss. How to splice a roof rafter plate.

Then a splice is in order. Trussed rafters are defined as triangulated timber frameworks positioned at close centres generally 600mm to form roof structures. Trusses have rafters tied together with other structural elements and are installed as a single unit while rafters are installed separately. The truss companies use a gang nail to splice wood together pictured at left.

These three planes are the top chord plane the bottom chord plane and the web member plane.