wall header span and load bearing walls

[mark kosse]

Hey folks, Anyone here know much about this? I'm enclosing a 8X24 screened porch. I added 3, 5'X6' picture windows, 2 28"X72" picture windows on each end of those, 2 32"X72" double hungs and I'm about to install the new door.

After that I'm would like to tear out the existing exterior wall and create a 7'X 20' opening with 2 4X4 posts for support. The existing wall has a door and 4, 34"X72" windows in it. The roof rafters are 22' 2X6. the header above the existing windows is 2 single piece 2X6's with .5 plywood in between. I want to span 8' between the 2 columns, if possible. Because the roof rafters are also a single piece of lumber it doesn't appear that this is a load bearing wall, just a support wall. The wall the roof rafters rest on is 2 single piece 2X10's, 24' long with .5 ply in between. The existing room is a cathedral ceiling room.

I've had 2 friends look at this. Both, like me, know enough to be dangerous. Both didn't think it was a load bearing wall and both didn't think an 8' span would be a problem. I know that 2, 2X6's should only span 6' on a load bearing wall. How do I figure out if the wall is load bearing or not? Would adding another 2X6 with .5 ply solve the problem? Tearing out the existing header would be a lot of work I would like to avoid, if possible.

Sorry if my construction terms are not quite right. I also understand that it is hard to diagnose over the internet. This is very rural property and it's hard to get anyone to come look at it. I just need some opinions.

Thanks, Mark

[Robert Reece]

Need diagram to understand better.
Maybe worth spending a couple hundred on an engineer?
Almost all walls bear some weight from above. Either roof or ceiling load. Ceiling load not so bad and in your area, roof load isn't to bad either.

A diagram would help a lot though.

[Mac McQuinn]

Robert is correct, You will need to put this into diagram form and determine the loads. The best text I've use on this subject is "Simplified Engineering for Architects & Builders" by Parker/Ambrose. Another text worth checking out with great graphics is "Graphic Guide to Frame Construction" by Rob Thallon.

Good Luck,
Mac

[Gerry Werth]

Almost all exterior walls are load-bearing walls, although the gable wall not as much as the eave wall, but a diagram would be helpful to understand what/where you are trying to span. But IMO, double 2 x 10s should be able to span 8 ft.

[Brian Effinger]

You absolutely need a professional engineer or architect to look at this. Check with your local building department to find someone in your area.

I'm an architect up here in NY and have gone into way too many buildings where people have randomly cut away the structure incorrectly and have had nothing but problems as a result. Something like an ounce of prevention....

[Jim Bowers]

Check with your lumber supplier and look at the LVL's. Ask they will have the engineering data you need.

[mark kosse]

I wish I knew how to put a diagram on the posting, but I don't. I could post some pics but I don't know if that will help.

As I stated earlier, the house is very rural and it is near impossible to get anyone to come out. I'd gladly pay to get it looked at, and for some labor help.

Jim, Thanks! I'll ask the lumber supplier. They may be able to help, they're not orange or blue.

[Robert Reece]

Post the pictures.
I am not necessarily saying you "definitely" need professional help. These computations aren't magic, but it does need to be done with care. There are so many variables that it's difficult to do it remotely. But a picture or two would be a great start.

[Maurice Ungaro]

After that I'm would like to tear out the existing exterior wall and create a 7'X 20' opening with 2 4X4 posts for support.

I'll say this much - a 20' span, with 2 4x4's for support sounds like a recipe for disaster. That header needs to be an LVL, or wood I-beam at the very least. An engineered truss would be even better.

[Jim Riseborough]

Im a strucutral engineer, and you should find someone to come out and look at it. There are things that an engineer might see that you dont. Plus, if you need a building permit you will need a stamped drawing

[mark kosse]

Thanks for the replies folks!

I decided to call the City of Houston Building inspection department and talked to an inspector. I explained that the house was not local but I lived here. He was more than willing to help. After I explained that I wanted to add a 2X6 with .5 ply to the existing header, he thought it wouldn't be a problem.

I'll post pics this weekend.

Maurice, Can you give me more info? What I want to do would amount to 2 5' spans, which 2- 2X6's will do, and 1-8' span. The opening will actually be 17'9". The roof rafters are supported by the exterior 2X10 headered wall. I'm not arguing, just trying to understand.

I'm looked for an engineer with no luck.

[Barry Vabeach]

Mark, I am not an engineer, but remember that anytime you install posts, such as the 4 x 4's, to carry a load from the roof, you need to think about carrying the load all the way to the ground, not just to the subfloor - so make sure whatever is under the posts is supported all the way to the ground. My guess is that your foundation went around the entire house and so you should be okay, but it doesn't hurt to check.

[Ron Williams]

After that I'm would like to tear out the existing exterior wall and create a 7'X 20' opening with 2 4X4 posts for support. The existing wall has a door and 4, 34"X72" windows in it. The roof rafters are 22' 2X6. the header above the existing windows is 2 single piece 2X6's with .5 plywood in between. I want to span 8' between the 2 columns, if possible. Because the roof rafters are also a single piece of lumber it doesn't appear that this is a load bearing wall, just a support wall. The wall the roof rafters rest on is 2 single piece 2X10's, 24' long with .5 ply in between. The existing room is a cathedral ceiling room.

As you describe it the exterior wall is load bearing. A 20' opening can be sized by most lumber yards that sell LVL beams. Don't guess at this get qualified local help>

[Jeff Nicol]

Here is a quck sketch of a gable end and side wall oreintation. As already stated the gable end would be easier to do as the load of the roof is carried by the side walls. When you say roof rafters do you mean the ones that are parallel with the ground? As I would call them the ceiling joists, the rafters are the ones that create the roof. Just trying to get it all straight in my head. So as the sketch shows each way, to do it on a side wall would take a lot more engineering and some proper support of the existing ceiling with a temporary wall built in the existing room. Then the old wall could be torn out and the proper structural beam could be put into place to support the roof and ceiling. If it is the gable end the process will be easier as there will be very little load down on the wall.

Hope the little sketch helps clarify the opening location.

Stay safe,

Jeff

[Doug Carpenter]

Mark,

Pictures will definately help.

I am a remodeling contractor and in the 20 years I have been in business I have done a tone of structural alterations.

No one wants to steer you wrong so provide as much info as you can.

I will look forward to seeing some pics and I will help if I can.

Thanks, Doug

[mark kosse]

Thanks again for all the replies. If you look at Jeff's more difficult picture, imagine half way down the roof span there is an interior wall. My house looks like this but the exterior wall was the outside of the screened in porch. The interior wall was the exterior of the house but was really an interior wall, if that makes sense.

I was wrong in my estimation of roof beam lengths. It is 15' from the peak of the cathedral ceiling to the exterior wall using a floor measurement. The roof is a 23 degree angle. I'm guessing the roof 2X6 studs are about 17', without doing the math.

I have pictures but I'm having trouble resizing them to post. I'll try tomorrow on a different network and see if that helps.

[mark kosse]

Here is a pic of the den showing the main beam at the top of the cathedral ceiling, the wall above the existing windows, the header above the new windows and the roof studs going over the existing wall.

[Doug Carpenter]

Mark,

Send me an email so we can talk on the phone. I have some questions so I'm sure I understand what you are doing.

dougcarpenterbuilder@windstream.net

Thanks, Doug

[mark kosse]

Whew was I wrong! I hadn't taken all the osb off beacuse I didn't have all the windows in. When I did I discovered I had a 2X6 header only above the door. Above the windows is a 2X12 header. I still don't believe the wall bears more than a nailing wall load, but a 2X12 should span 8' either way. Do you concur?

TIA, mark

[Doug Carpenter]

PM sent

Thanks, Doug

[Glen Butler]

It all depends on what loads are on the 2x12. If it has any point load no. If it is holding a simple roof structure spanning less than 30' probably. More recently I never have a header span more than 6' which is not at least 9 1/2" LVL.

[mark kosse]

Geez, I forgot to add pics.


Thanks Doug! Everyone has been helpfull but I'd like to point out how helpful Doug has been. Talking me through a lot and adding great ideas. Thanks again.

Glen, a roof load only, about 17'.

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[Ben Franz]

Mark,

I am a remodeling contractor ....

A contractor named Carpenter - too perfect! :D:D:D