wall header span and load bearing walls

[kossetx]

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. I know this is supposed to be about tractors but I need advice.

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 or advice.

Thanks, Mark

 

[beenthere]

A pic or two would help in making a comment. Sketch would help also, but at least some pics.

Prolly not much snow load to worry about ?

 

[PILOON]

Instead of 2x6 + 1/2ply do it all in 3/4 ply+construction adhesive and dense nail patten.
Be sure the ends are sitting on your jacks (2x 4x4's (better 4 2x4's,glued and nailed)) and be also sure that you block and fill under the flooring under the added jacks to transfer the loads downwrds to the foundation.

In effect gluing and nailing ply becomes the equivilant of purchased laminated beams.

And, yes since the 'cut out area' is bottom of trusses on over the foundation, I gather, then it is actually load bearing.

Not being in a snow load area, I think this should cover your needs.

Double 2x6's considered OK for 6ft span so laminated as suggested should be OK for 8 ft.

 

[theboman]

Back in 79, 80, 81 I worked as a flunkie for a few contractors. We always built our beams and headers. Seems for windows and doors we used two 2x8s and then 1/2" plywood with grain running in opposite direction.

Seems main beams on homes were 2x10s, but maybe it was 2x12s. I've had a few blows to the head since then!

 

[radioman]

I would start by pulling off the siding in the porch area just at the ceiling area and higher to take a look. I am going to "assume" its a load bearing wall since most porches are outside walls of a house. So treat it as such. I did the same thing with my old house I am currently renting out but the span was 12 ft. I cut up some trees for posts and braced up the ceiling right on a 2X12 next to the wall I was going to take down. I put 2X12 and half inch plywood in middle with glue and nailed everywhere 6 inches apart. keep in mind when I did the plywood, I did a full 8 feet on each side and cut a lap so it intersects each other 4 ft. overkill I know, but overkill is good . Luckily I wanted a coat closet nest to the new wall so I built 3 ft wall under one end and 4X4 post on the other end buried into the wall corner. Its still standing there with no cracks in drywall on first/second floor.

 

[Jeepnford]

If you have any real lumber yards left they usually have someone that can look up the specs on the laminated beams and usually give you a pretty good clue on what you need. Some of that is also available on the web. Try a search on v-lam or LVL beams or building span charts. It's sad when the guy at the "pro desk" at the big store knows less than I do. That's not easy.

 

[kossetx]

Thanks for the replies! In the case of this porch the wall outside the porch is definatly the "main" load bearing wall. From the middle of my den to the wall outside the porch it is 15' by floor measurement. The roof is built of single piece 2X6's which, without doing the math, are about 17' long each. The wall at the edge of my den is built up to the roof, which is why I don't believe it is load bearing. I have pics but I'm having trouble resizing them and will try tomorrow on a different network.