How big of an LVL, and how many, do I need?

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Old 12-29-13, 02:31 AM
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How big of an LVL, and how many, do I need?

I have a one-story home with a nearly finished basement under most of the house, with a crawlspace under the rest. At one end of the house are two bedrooms with bathrooms and closets sandwiched between them. One of the bedrooms, the master bedroom, is 16 x 16.

The finished basement runs for ten feet under the master bedroom. This last part of the basement forms a 10 by 16 foot room, setup to be a guest bedroom with a proper window and walkout door. The south end of the room has a bathroom and closets. The east side has a 16 foot wall with a single doorway. The west side has a 16 foot wall with a partially excavated, mostly sandstone based, six to four foot high crawlspace.

Using a small Chicago Electric hammer chisel, I have cut out several chunks of the sandstone. I was thinking to remove about 90 square feet of the rock and extend the guest room into that area. It would give me a much more ample guest room.

But now, I hit a snag.

From under the house and looking up at the framing, I think the bedrooms were added sometimes after the original house was laid out. The original floor joists are four by eight beams running north-south. But under the bedrooms the joists are regular two by eights running east-west.

Well, it turns out that the joist for the master bedroom span from the 16 foot east wall, a bearing wall, to the 16 foot west wall. Unfortunately, they end there and another, shorter set of two by eights span the crawlspace.

Remember that a 16 foot wall with a partially excavated crawlspace behind it? It too is a BEARING WALL. Dangitty dang dang dang!

So, I ask again, now that you know the situation, given that I build temporary walls east and west of the 16 foot bearing wall and emplace two properly footed LVL post, can I cut in a LVL with joist hangers to replace the bearing wall?

Ceiling space is limited so if I have to through-bolt two or three together to keep an eight inch profile, the big question is, for a 16 foot span over a bedroom with bearing walls 10 and 6 feet out, how big of an LVL, and how many, do I need?

Thanks in advance.
 
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Old 12-29-13, 05:22 AM
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LVL's should never be cut along the width.
It's in you best interest to hire an engineers to design a fix
 
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Old 12-29-13, 06:04 AM
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You say "LVL post". Are you actually considering using LVL as a post or are you planning on installing a LVL beam in place of the bearing wall? Also, when you say "cut in a LVL" I assume you mean install a LVL or are you somehow planning on cutting the LVL?

I don't completely understand what you have and what your planning but if you search online for "LVL span table" you'll find span tables for various sizes and configurations of LVL beams. I don't know of any situation where LVLs are used as posts so you may be out of luck there. In either case LVL are an engineered material so their use requires Engineering. Many LVL companies will provide the Professional Engineering with their products so it's not as bad as it sounds.
 
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Old 12-29-13, 09:10 PM
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Question What I meant by cut in . . .

No, I do not mean to cut the LVL.

Rather, I propose to put in temp support walls, cut the ends of the existing joists, put hangers on an LVL (or several through bolted), and then raise that LVL with hangers up into the cavity to support the existing joist, transferrin the load to posts at the ends of the LVL.

Yes, I will contact GP or other LVL team to get their buy-in, so to speak, but is this possible?
 
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Old 12-30-13, 05:45 AM
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Sounds to me like you need to use steel.
 
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Old 12-30-13, 05:48 AM
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Yes, it is very possible and is commonly done.

Generally LVL's are not through bolted as they don't want holes bored through them. The LVL supplier will probably provide you with a nailing schedule for attaching the beams together.

The LVL manufacturer's websites usually have span tables. Looking through them will give you a good idea of the beams you will need so it's a good idea to at least give it a quick look to see if LVL's will even be a possibility. A few months ago on the board someone wanted to span a long distance and support the floor & roof above but only wanted a beam 8" high. It was nowhere near possible with any LVL and meant they had to look at steel instead.
 
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Old 12-31-13, 06:31 PM
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Cool Yes. Thank You. It can be done.

Pilot Dane et al.,

Yes, Thank You. I contacted Georgia Pacific and spoke to one of their property managers (guys that keep their products correctly built). He explained a lot of stuff to me, including floor loads and how their products worked, how loads transfer across the beams to the nearest post, and a lot of stuff that made sense to me as I took copious notes. In short, two of their, as I call them "two by eight" beams will carry the load I need. Three will be a bit of overkill but not insanely so.

The local "Building Supply Warehouse" in West Columbia has a program to run the numbers and even print a plan, as well as the association with GA PAC to provide (and even deliver) the product.

So now, I continue to crack rock and look forward to the next steps. Oh, GA Pac has a diagram for through bolting and at some point and for some beams, if sistered together they must be through bolted.
 

Last edited by Robert Lang; 12-31-13 at 06:33 PM. Reason: Add Info
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