I gotta get off my butt and away from this computer pretty soon, and start building this thing I’ve been planning.
There are a few pieces of the puzzle I’m scratching my head over, and this is one of them. Take a look at the attached pic.
I’ve got to frame and sheath the part of the eyebrow dormer that is roof, enough back to get these lay-on rafters bedded at their seats.
I’ve framed only a couple lay-ons before. I’m not a framer by any stretch of the imagination, but they went OK. But they were straight valleys, and putting a valley cleat in was no-problem-o.
But this time I’ll have got a valley thats curving two ways.
What would you do here? Or, is the whole scheme bogus, and I should be thinking of some other way here.
The architect’s drawings leave everything to the imagination in this area.
Replies
Gene,
I don't know what you plan to sheath or finish the roof with but if you were going to use two layers or 1/4" plywood and asphalt/fibreglass shingles and your rafter spacing was 16" in this location I wouldn't worry about it too much. If you want to put some blocking in from below, maybe some 2x12's on the flat it would be simple to do. Your eyebrow roof won't be very much of a load.
Does that answer your question?
Do a search. I think Mike Smith has posted a sequence of photos showing this, as he is the Master of eyebrows. Within the past 2 years.
F
Gene, could you post a bigger version of that Archy's drawing ? I'd like to see how he designed it.
Ain't much. This is all she's got. Really. No section, no callouts, no nothing.
Piece-o-cake.
View Image
Aahhh! Forgot to indicate marking the blade angle at the top of the "Small Block" on the end of the rafter.
SamT
Gene,
String a mason line from your last truss closet to the eyebrow on each side so that the line touches the top of the eyebrow at the center point. Now nail a ridge across in between the two end trusses and now you can get your first layon rafter in the center. Nail a block underneath the sheathing and then nail your center rafter in.
Don't remove the mason line, use it as a guide to set the rafters in plane with eachother at the top. All you need to do now is string another line at the top of the ridge and down across the top of the first mason line at your 16" or 24" center mark until that line hits the sheathing of the eyebrow and that's where your rafter will end.
String another line from that second rafter down to the end of the outside end truss and use that line as a guide and repeat on the othger side.
The mason lines don't lie and they will help you set the rafters exactly where they need to go.
I hope this makes sence to you because once you've set the center rafter in place and the ones on each side of them you now can shorten the distance for putting line 2 and 3 on an angle to get the rest of your valley jacks. Just try to put blocks under the sheathing where they go.
Joe Carola
Edited 3/11/2005 8:06 pm ET by Framer
Gene,
Here's another shot with the ridge.
Makes perfect sense to me, Joe. Thanks.
The rafters are cut to a 20' R and as you can see when looking at my pic, the birdseye has tangent fillets, which have 9' radii. Thus the valley is a faired elliptical curve, each side.
Would you try to nail some blocks to the lay-on sheathing between rafter tips as some nailing for the slope sheathing coming down the 4-1/2-pitch rafters? Or would you just nail through the plywood-to-plywood joint, and call it done?
"Would you try to nail some blocks to the lay-on sheathing between rafter tips as some nailing for the slope sheathing coming down the 4-1/2-pitch rafters? Or would you just nail through the plywood-to-plywood joint, and call it done?"I would through some 2x's on a flat flush with the top of the rafters. Just take some scrap and lay them on top and scribe the bottom of the block to the angle of the ratfters and cut them and nail them in, it will only take a few minutes.Joe Carola