Roof Trusses - Nail Plates or Ply Gussets?

[meb97me]

I need to make 17 trusses for my timber workshop (10m long building based on 600mm centres). The trusses will span 3.4m and have a 18 degree pitch

i've made a jig to cut all the wood angles but i'm still abit unsure about the best method to join them all together.

Would it be ok to use some nail plates such as these

http://www.toolstation.com/shop/Str...ised+Nail+Plate+80+x+150mm/d210/sd2797/p25743

or would i be better making some plywood gussets? and if so what sort of thickness would i be needing.

cheers for your help

Matt

 

[noseall]

Why are you making preformed 'trusses'?

Why not just build a traditional cut roof and nail/screw it together?

 

[meb97me]

The problem is the walls aren't exactly parallel due to a narrowing drive so i need trusses so that the cross members can sit ontop of the header plates rather than cutting bird mouths into the rafters as the roof then wouldn't be level etc

hope that kind of makes sense

 

[meb97me]

sorry i dont think i fully understood your question before. I wasn't entirely sure what a "cut roof" was.

I'm basically just making the roof frames at home on site as it were but just wasn't sure of the best method of screwing them all together. is it simply a case of using screws or would using thise nail plates provide a stronger solution for joining the cross supports to the rafters?

thanks for any advice

 

[noseall]

If you are simply connecting the trusses together with butted joints, i.e. not mortise & tenon, glue & screw etc, then you will require a more robust fixing method than just screwing or nailing.

Manufactured roof trusses are butt jointed but these are connected using gang nail plates that are pressed in by machine. They are extremely strong.

Ply gussets may make the trusses heavy where as nail plates may encourage splitting.

The truth is i am not familiar with making my own trusses as it is cheaper to buy them from a manufacturer! They are both very lightweight and reasonably strong, though the section of timber used is rather spindly.

My original suggestion regards a cut roof would involve birds-mouthing onto a wall plate and perhaps will not be practical solution as fitting to an out-of-parallel set of wall plates would be a real pain!