Joints for truss building

[EJ]

In several carpentry books I saw ring joints for connecting framing members with bolts. They look like short pieces of 2" pipe with a split. They are centered in a groove around the bolt to carry more load than the bolt itself. I have not been able to find them.

I need them to build a flat truss to span 32'. After reading much about failing nail plates in commercial trusses and having trouble finding a reasonable source for it I decided to overbuild it and make it myself. I want to connect the pieces of the top and bottom cords from 2x6x16 (three layers) with staggered joints in points of minimum stress. I will glue the layers as well.

EJ

[Larry Caldwell]

Split rings have become less popular with the advent of modern adhesives, but if you are using rough sawn lumber they can give you a much stronger joint. They are pretty labor intensive.

Your idea about slicing a pipe was right on the money. That is how you make split rings. Then assemble your joint, drill it for a bolt, disassemble it and use the bolt hole as a pilot for a ring cutter, cutting to 1/3 the wood thickness. A split ring to attach a pair of finish 2x12s would be 1" x 3" x 1/4". 1/2" of the ring would be bedded in each 2x12 when the joint is assembled and bolted back together.

If you have smooth wood surfaces, just slather some weldwood in there and bolt it, adding a few nails to clinch up any loose spots. The result will be just as strong, and it will only take 1/3 the labor. You are right not to trust clamp nails. If you want to use conventional nails, you can use a nail that penetrates through 1/2" and clinch it over cross grain.

Some truss manufacturers still use the old style plywood gussets and glue. The disadvantage of plywood was if the truss took a lot of weather before the roof went on. Sometimes the plywood would start to delaminate. A really modern truss manufacturer would use engineered members for the cord and rafters, so there would be no joints in the cord and the only joint in the rafters would be at the peak.

You can trust a quality commercial truss. Of course, you can trust a home built truss too, though it is likely to cost more.