carpentrycoverledgerpatioroof
I want to attach a patio cover to my house. Trouble is the clearance between the window and the roof rafters is too small for a ledger. I was considering the option of attaching to the roof top like this:
Is it ok to attach to the rafters like this to support and distribute the load?
If so, any reinforcement required to the roof skeleton?
Patio size would be ~25x12ft.
Since the new rafter section will cover any siding you may remove, layout how far the rafter section covers the siding and cut it about a 1/4 to a 1/2" lower. This will let you find the framing pretty easily, even remove a little subsiding to confirm, careful how deep you set your saw. This will show any conditions you may need to attend to. Set the bottom of the ledger at the on a chalk line set at the level you predetermined before you cut the siding. Set a ledger at the top of the rafter section as well to control rotation of the new section. This is an expansion on what Comintern suggested with his ledger and joist hanger idea, make sure the joist hangers approved for your framing condition.
Here is a little sketch to help illustrate. Doing it this way will allow a finished ceiling to go uninterrupted to the existing wall.
I agree with Ed Beal. But yes, there are 2 ways to do this & they're equal in strength, for what's planning to be done. However, get a Permit from the Building Dept., so they can approve or correct the design, fasteners & supporting post(s) dimensions & footings. Plus, they can record that the patio was converted to a porch.
1st way is to do ledgers on both fasciae into structural members. Typically you'd pre-build the new structure so the short rafters are end screwed or nailed through the blue-line's ledger & the long lower beam & top ledger are through the side ledger (rafter). Also, use joist hanger type connectors to ensure nothing can pull away from each other.
2nd way is really the proper way & is likely what the one contractor was talking about. You'd remove both fasciae & screw or nail directly into the structure. For the slope side this is much less important. But, the blue-line top would have the new rafters cantilevered or sistered onto the home's existing rafters. This is much more secure & even lets you re-use both fasciae.
Best Answer
What you have pictured is a typical hip detail. As long as you use proper sized lumber for the span and center dimensions it looks fine. The only thing I see is a lack of metal rafter hangers, bird's mouths and collar ties over the open span. Collar ties are not absolutely necessary if a cathedral design is wanted. basically, it looks OK. Check your local codes in case they have special requirements in hurricane prone or heavy snow load areas.