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Rafter resting directly on top of joist

948 views 9 replies 5 participants last post by  Teh Swede  
#1 ·
I am working on an ICF framed house that has concrete embedded (in concrete) hurricane anchors. Originally for trusses, but, now doing a compression roof. Hardware company (Burmon) indicated rafter framing can be done as well with them but doesn't have a reference detail for it.

Has anyone ever framed where the rafter sits directly on top of the joist (which is cut at an angle), instead of next to it on the plate and nailed together (can't do that since I don't want the joist on the concrete, and the anchors are already set)? Not sure if anyone has a framing detail of a rafter directly on a joist?

There is a picture on Burmon's site that shows what I'm talking about, although I'd assume I'd need a tie plate behind the saddle plate to make sure they are connected together at a minimum:

I could also do a separate after tie above that between the points using fastening schedule in IRC, but, hoping for other options I can present to the building dept.

Other options are also appreciated.
 
#3 ·
Right, definitely need a tie plate or something to the left (at least). For trusses they work well and have an install guide that is focused on those. They say they work with rafter framing as well, just trying to figure out the best way to handle that in this situation (since I'm stuck with them.)
Here is the link to the actual product:


This? The upper right screw doesn’t seem to be doing much. Seems like the company is showing a picture of something that hasn’t been well thought out.

View attachment 575587
 
#6 ·
Pounder beat me to it. I would probably do a gusset.

I think part of the reason that 2x4 block detail you provided works is because the block can’t pivot against top rafter plate.

We recently performed roof framing repairs on an old kit house that had 2x4 rafters cut at an angle, resting on top of ceiling joists and lag screwed from the top so they couldn’t spread. But I’d think that would be tough with any rafter bigger than a 2x6.