Beam Span?????

[crazyal]

Go with the LVLs. I have an 18' span under the living room. I had the choice between two 18" or 3 15" to span the distance. Headroom wasn't an issue so I went with the two 18". They are rock solid, much stronger than a 2x10. Even if you do add that support I would still spend the extra money vs. trying to put steel in between 2x10s.

Your lumber yard should have asked you for all the information and if they told you what size LVLs you needed that's what I would get and deal with any padding issues and span the full distance.

 

[dieselscout80]

Do install a steel plate, as you were intimating above. Bolt it through, in a similar fashion, as you did with plywood and nails in the sandwich. A steel plate will really assist in keeping the bowed effect, sag or flex out of that beam.

13'7 is roughly the length of the average two car garage door header beam. These are sagging all over the country, when not sandwiched with steel. Ask any garage door installer. :laughing:

How thick of steel would you use?

 

[ultrarunner]

Any updates???

 

[dieselscout80]

Any updates???

Well I'm going to for sure limit the span to 13' 7".

I'm looking at the ways to provide additional support to the existing beam.

The options are:

1. To add a beam below the existing beam made of 2"x4"x0.25" + 3"x4"x0.25" steel tube between two 2"x6" (maybe 2"x8" ripped down). The 2"x6" on the sides will replace the current ledger and keep the current beam from moving off the support beam (works for the LVL option too).

2. Cut out about 3" to 4" deep of the current beam's 1/2" plywood and insert a piece of 1/2"x3" steel with a 0.25"x5" wide steel welded to the bottom to make a upside town "T" shape (kinda like a I beam with the top flange removed). The great thing about this way is no loss of head room, but how do I cut the plywood out which in nailed in? I can think of a few ways to cut the plywood out, but all kind of scare me.

1. Use a chainsaw cutting over head and a gas chainsaw in the house not good, but if I built a depth stop and cut using the top of the bar and pulling the saw back there wouldn't be kick back issues.

2. Use a 15" circular saw and build a track so all I have to do is push in rather than hold it up and push it.

3. I think this will work best take my router (has 1/2 chuck) and use a 1/2" steel drill bit (nails would not be an issue) and build a track so all I have to do is push in rather than hold it up and push it.


No matter which option is used the existing beam will be screwed/bolt through to tighten it as show in the steel beam options.

I'm currently tearing out the bath room to prep for the beam work.

 

[Iplayfarmer]

Isn't remodeling fun!! I can empathize 100% with your situation of having to work with what's there while still trying to improve upon it.

Good luck.

 

[ultrarunner]

I would like to do the same...

I have a 4x8 wood beam under the middle of my 22 x 30 concrete garage floor. The Beam is supported by a 4x4 post every 7.5'

Removing one post would double the span to 15' and open up the 7' high crawl space under the garage and provide storage space next to my BX23...

 

[mojoinco]

Scout, given that I would rather weld above, than try to run a power tool overhead...you can see where I would go.

Or, what about running an additional 2 x 10? Since you are only adding what, less than 2 feet to the span, wouldn't that work? Offset to the long span side (12' 3")? Easier to get a sawzall in and cut the floor joists shorter. Run a temporary header and posts under the joists being cut (and screwed to hold them in place so they don't 'pop' and twist when cut).

Only my thoughts, not because I have any engineering knowledge. I suppose running an lvl the same way is similar.

 

[LD1]

I would like to do the same...

I have a 4x8 wood beam under the middle of my 22 x 30 concrete garage floor. The Beam is supported by a 4x4 post every 7.5'

Removing one post would double the span to 15' and open up the 7' high crawl space under the garage and provide storage space next to my BX23...

If you are asking for advise, more info is going to be needed.

Doubling the span is going to require a significantly stronger beam. But there is no way to figure it without knowing the loads involved.

And trying to match to something that is as strong as your current 4x8 spanning 7.5' would not be hard to do, but we need to know what type of wood the current 4x8 is in order to figure out how much load it can currently handle. It would be simple to reverse engineer from there, but their is a big difference between a white pine beam and a hardwood beam, and everything inbetween.

And it sounds like headroom is going to be an issue too. If you are wanting to maintain the current 8" of beam height, that about rules out wood all together. A steel 8" beam looks like the way to go. But just how heavy of a beam is going to depend on the above mentioned variables. Not to mention, you may have to beef up the support posts a bit if you are going to remove some of them.

 

[ultrarunner]

If you are asking for advise, more info is going to be needed.

Doubling the span is going to require a significantly stronger beam. But there is no way to figure it without knowing the loads involved.

And trying to match to something that is as strong as your current 4x8 spanning 7.5' would not be hard to do, but we need to know what type of wood the current 4x8 is in order to figure out how much load it can currently handle. It would be simple to reverse engineer from there, but their is a big difference between a white pine beam and a hardwood beam, and everything inbetween.

And it sounds like headroom is going to be an issue too. If you are wanting to maintain the current 8" of beam height, that about rules out wood all together. A steel 8" beam looks like the way to go. But just how heavy of a beam is going to depend on the above mentioned variables. Not to mention, you may have to beef up the support posts a bit if you are going to remove some of them.

My apologies to Dieselscout80... I read your post and have a similar conundrum.

Existing Beam is 4x8 #1 Doug Fir.

Ceiling height is 7' under the floor joists minus 8" under the center span 4x8 beam.

One thought is to sister steel channel with cap bolts to both sides of the 4x8... kind of a reverse Flitch Beam.

I can get two 16' lengths of 8" channel and put them back to back with the 4x8 sandwiched between. This method would not require temporary cribbing to support the floor since the original beam remains in place.

Existing beam length is 30' comprised of 2ea 15' sections...

Floor joists supporting plywood and the concrete garage floor above rest on top of the beam, 16" on center.

The former owner/builder had loaned his plan for the shop/garage and lost track of where they ended up...

Shop/Garage is 22 x 30 concrete slab supported by 2x4 cripple walls and one 4x8 beam down the center...

 

[wrath]

I'd go the steel route and build it in the basement. I'm always amazed when I see people marry more than two 2x for a beam. I always figured it was because it's cheaper to do that than to weld something up.

I never had much faith in LVLs after seeing one fall apart due to getting wet. Same for engineered joists. I'd believe in a glue laminated beam before an LVL. Something tells me in 50 years they will be bulldozing all the houses built with engineered lumber while the 1970s and older homes will still be there.