patio roof


Old 03-15-05, 07:18 AM
Thread Starter
Join Date: Nov 2001
Posts: 21
Received 0 Votes on 0 Posts
Question patio roof

I am wanting to build a roof off the back of my house. My plan is to attach a header board,then come off with a shed roof with a pitch of 4 12.
The length will be 40' long. Because of an existing fence I will need to have the support posts to be placed at 9'6" form the back of the house. I have a few questions:

1. What size joist and support crossbeam should I use?
2. What size and how many posts?
3. Based on this info what kind of overhang will be ok?

Any help as always os greatly appreciated.

Old 03-15-05, 09:02 PM
Doug Aleshire's Avatar
Join Date: Feb 2002
Location: United States
Posts: 4,679
Received 0 Votes on 0 Posts

What I see is that we are missing part of the information required.

We are talking a 4/12 pitch
We are talking about a Shed roof - ledger attached to house
We are talking about 40 feet in width
We are talking about 9'6" in total depth

Here's what I would need to know for starters,

1. What are your setback requirements? Code Requirements?

2. What is this going to be used for? patio cover, storage, habitable

3. How high is the outside wall, per say, of this roof off grade?

4. How much overhang are we talking about 6", 12", 24"? This may be Code restricted due to the fence you mentioned

5. What is the roof covering going to be?

6. What are you thinking of using for rafters or are you considering pre-manufactured roof trusses?

Not a simple answer to a fairly simple question.
Old 03-16-05, 06:44 AM
Thread Starter
Join Date: Nov 2001
Posts: 21
Received 0 Votes on 0 Posts
Fair enough.

-This will be on the back of the house--over a concrete patio
-The header will be attached 12'(approx) high on the back of the house. I know I shoudl be more exact, but this is going to follow a roof line from kitchen bump out.
-Overhang--does this depend on tthe size of the rafters? I would like up to 24"
-Roof will be shingled to match the house
-Rafters--2X6 or 2X8?????
-Fence is n ot a factor, it runs perpendicular to the house

I realize a lot lost in trying to explain this. And there are no simple answers. MY two biggest concerns are size and placement
2.rafter size and overhang

I have a scanned picture that may help you see what I am doing/

thanks again.

Old 03-16-05, 07:21 PM
Join Date: Mar 2000
Location: Arlington, WA
Posts: 9,238
Received 0 Votes on 0 Posts

You are just BEGINNING to get into it. There are still more questions that have to be answered. Snow load?? Wind load?? Your seismic zone??

The 40' width isn't an issue, but the projection is. If you are doing this in downtown Miami, snow load and seismic zone really doesn't enter into it, but certainly wind load does. (They have hurricaines!) Whereas in upstate Minnesota, never been a hurricaine there, but there is snow. Or in 'Frisco, snow and wind aren't much of an issue, but that city has been know to rock and roll, and I'm not referring to Gracie or Janis!!

Your best bet is to go to your local bldg. dept. and find out what snow and wind loads you have to build to, and what seismic zone you are in. They will also tell you about the setbacks you have to conform to.

Thread Tools
Search this Thread
Ask a Question
Question Title: