adhessive choice

[Kenneth Reidy]

Hi All,

I am fabricating 19 "I" section curved trusses for a new shop. Basically I cut a curved OSB web and laminate 1/2" plywood chords top and bottom. The end product is a curved TJI. The last time I did them for a house, I used epoxy to glue the 3 layers of plywood together. This was quite satisfactory although I am not a big fan of dealing with epoxy. Does anyone have an alternative suggestion? Ease of application and cost is an issue. The trusses are 32' long and the total lengths of chords are 3,648 Lin. Feet. So application and cost are an issue.

Many Thanks!
Ken
Albuquerque

[Jim Andrew]

Think you need to elaborate some, as this is not a common building procedure. I've used manufactured TJI's for floors, and amazed by how strong they are, but they had a piece of lumber grooved and glued to the top and bottom of the osb. I'm thinking the glue is the most important part of the tji. And how do you glue between the osb pieces?

[Henry Ambrose]

You might be getting in over your head on this. This would usually be considered an "engineered" commercial product. If you're asking about what glue to use I'm guessing you don't have engineering input. That said, I'd be inclined to build something like this myself but I'd get lots of hard, serious information first and ask an engineer to look over the design and techniques.

I think the manufacturers use some kind of phenolic resin glue, probably using a process that is not practical for you - not sure what. I'd be inclined to use resorcinol glue, its properties should meet your needs. But you really need engineering help with this, don't go on my word.

The other thing is - have you asked around at truss manufacturers? I'd think most (that are still in business) would be happy to build this. And the price should be pretty sharp given the state of our economy.

Are these trusses for a curved roof?

[Brian Libby]

Go pre-made, I bought 14" I beams 26 feet long (2x4 on top and bottom with an OSB web) for my garage and only cost $ 60.00 each (only 2 years ago).