Patio Roof Tie In

[f4family]

I am attempting to construct a simple patio cover that is about 12 X 20. I have the design down for the most part but can't make up my mind on the tie in to the exist house. I have seen people attach the ledger to the existing house rafter tails however I don't think I would get a good enough slope and I'm not sure about the stability of such a tie in. One thought was to go up a foot or so on the exist roof and peel off the shingles and tar paper down to the decking and bolt the ledger board across the decking through to the rafters on the exist house. Then taking the patio roof rafters off that ledger. Is this a sound solution or am I asking for it?

[Don_P]

That is typical. If you can put the ledger very close to or directly over the exterior wall that would be the strongest. Kickers down to the wall from the underside if there is a heavy snow load. As you crawl up onto the rafters you'll need to think about the increased load on the rafters. You're right, don't hang it on the tails.

[f4family]

Thanks for the tip. I live in Houston so snow isn't an issue. Now for a load perspective do you have any advice on when I would be pushing it. The cover will only go out 12 feet from the house and I plan it to be a fairly simple asphalt shingled roof. No major bells and whistles, maybe a ceiling fan attached.

[mjpliv]

In your area I would think wind loads would be your biggest concern. I would suggest you look at the connections between your footings/posts and posts/beam and beam/rafter as well as rafter/extisting house. Check out the various galvanized metal connectors made for these details at http://www.strongtie.com/ . These products are available at most large building supply outlets.

When dealing with an open canopy like this we tend to design for gravity and forget about the uploads from wind that are trying to lift it right off the side of the house.

[mjpliv]

Oh, and as far as the structure goes, without a snow load, technically 2x6 @ 16"oc would work but I would hedge towards 2x8's @ 16" or 24" oc for a solid structure. Make sure you use solid blocking about mid-span and/or furring strips to keep the rafters from twisting up. I would suggest even using at least the blocking if you are applying a v-groove type wood ceiling finish.

[f4family]

I really appreciate the feedback. This is something I would really like to do myself verses a contractor not only to save money but I really enjoy building and working with my hands.

As far as footing to post anchoring. Do you recommend putting the post directly in the concrete footing or anchor the post to the footing with one of the recommended connectors?

[mjpliv]

If it was my project I would use the connectors. The Simpson Strong Tie anchors come in a variety of shapes and sizes. If you allow a 30 pound per square foot up load you will be dealing with a total of 7200 pounds of total uplift to deal with. You may want to check with an engineer or building official to see what wind loads you should be using. You could probably get that free over the phone and just do the calculations yourself. Use hurricane ties to bind the rafters to the beam and hangers at the ledger on the house.

[cvh0828]

Sounds like you are on the right track. I hired a contractor for my job and it was a disaster, I wish I had went to this site before I began my roof over my patio. Just make sure you have enough pitch. I think a 4/12 is the minimum you want. Coming off the roof is common just go up high enough to get the properly pitch.