90 degree joint for lean-to roof joist

[Chris152]

Excuse the rather rudimentary artwork but I need to join a joist to the one (temporarily) in situ. It'll have to support further 5 smaller joists (2"x3") that will in turn support a plastic corrugated roof. It'll be joined to another 6x2 at the other end (it's 3m long).

What joint should I use for this?

Thanks, Chris

EDIT - On reflection, I think the easiest and strongest thing is to add another vertical post at the junction of the two joists, so both can attach securely to it and it's further supported onto the ground.

Problem solved, I think!

 

[Chris152]

OK, Mostly in place now. But what is the correct screw spacing for miniature corrugated plastic sheet? I've searched the net but can't find the answer.

 

[MikeJhn]

Look up the manufacturers details should recommend fixing details, but I would say every third corrugation on the high point with rubber washer fixings, have a look at Unduline roofing sheets for the idea: https://www.eroofs.co.uk/uploads/manuals/Onduline Fixing Guide.pdf

 

[MikeJhn]

EDIT - On reflection, I think the easiest and strongest thing is to add another vertical post at the junction of the two joists, so both can attach securely to it and it's further supported onto the ground.

Problem solved, I think!

Or let a corbel into the existing post to support the new Rafter.

 

[Chris152]

Look up the manufacturers details should recommend fixing details, but I would say every third corrugation on the high point with rubber washer fixings, have a look at Unduline roofing sheets for the idea: https://www.eroofs.co.uk/uploads/manuals/Onduline Fixing Guide.pdf

Thanks Mike.

Should 60cm spacing of battens be ok?

edit - Sorry, that looks fine according to the link you shared, Mike.

 

[MikeJhn]

It all accords where you live and the loading you expect on the roof, high winds and snow then closer spacing, it's up to you, personally I would only want to do this once so would go with 450mm spacing.