Beam Span?????

[LD1]

The pictures and diagrams paint a whole different picture.

If I understand them correctly, you are building a wall under one side of the beam that will continue half of the distance. And instead of haveing the beam divided into 3 spaces, you are wanting to have the 17' side clear-span.

If that is the case, You shouldn't need to worry about the side with the wall being built under it. EACH of the studs is going to act like a post and carry the load int the floor. So I wouldn't touch that side.

Now that we are only dealing with the 17foot section, As I currently understand it, it is all open underneath with the exception of the 1 post about 4'6" from the wall you are building and a 12'6" space on the other side all the way to the foundation wall correct?? Your goal is to eliminate that "off center" post and clear span it right???

You have a few options here. 1st woudl be to not touch the beam and just add a post @ the mid point of that 17' span. While not clearspanning, it would certainly look better than the current off-center post.

I don't currently have the load abilities of LVL's in front of be but I would think that a double 14" or 16" would certainly do it. But LVL's are pricey and you will give up head room. If you can afford the headroom, that sounds like the way to go. If the headroom is an issue, steel is about the only option you have left. You can get a beam pleanty strong enough and still not go over the 10" deapth you currently have.

 

[rtimgray]

I just taked to a building supply place and they recommended removing the old beam for the 17' span and replacing it with 2 LVL's either 14" or 16" deep. LVL's are 1.75" thick so I'll have to put a 2"x10" or a 2"x12" between them to equal my current beam width.

I'm not sure about that - looking at the LVL tables I'm looking at say that a 1.75" x 14" beam spanning 16'-6" will only support a total load of 342 lbs. Unless I'm completely misunderstanding this, is looks like maybe they were thinking you were looking for floor joists, not a beam to hold up floor joints.

Again, maybe I'm looking at the wrong tables....

 

[rtimgray]

It looks to me like it would take a 3 1/2" x 18 or a 5 1/4" x 14" or 16", depending on if its Timberstrand, Microllam or Parrallam beam.

But it looks like you could do it with that. The negative would be the loss of headroom. If you replace the existing 2x10 (9 1/4") with a 14" depth, then you're only losing about 5", which isn't too bad.

Good luck and take care.

 

[dieselscout80]

The ceiling in the basement is 8' so losing even up 8" will not be a major issue. I''' just box it with sheet rock the rest of the ceiling will still be 8'.

If I went with 3 LVL's which equal 5.25" wide what would be the best way to shorten the floor joists to allow the wider LVL beam to fit where the current 5" beam is?

 

[dieselscout80]

I just had another idea.

Would it work to use three 2"10" with two pieces of sheet steel .25"x9.25" the same length as the 2"x10" this will equal 5" like the current beam.

 

[LD1]

If I went with 3 LVL's which equal 5.25" wide what would be the best way to shorten the floor joists to allow the wider LVL beam to fit where the current 5" beam is?

BFH (Big freaking hammer)

Just kidding.

Your house is only 24' wide (perpindicular to the beam.)

According to the chart I attached, you only need to be 3-1/2" thick for a 16" beam and 5-1/4 if you choose the 14" beam.

So if you went with the 16" and baybe sandwitched them around a 2x12 with a 2x4 on top, you will be at your 5" thickness. And the 2x12 and 2x4 will add a little more strength for peice of mind.

Look at page 3, the second chart. The one for beam spans with floor joist that are not continuous. But even if they were, the results are the same. Also note that this is for 40psf live and 15psf dead loads. But then again, if you add the 2x4 and 2x12 between, you should have nothing to worry about.

oops, forgot the link http://www.parr.com/PDFs/LP LVL 1.9E.pdf

 

[dieselscout80]

We've decide to shorten the span to 13'7". I'm going to make another beam to go under the existing beam to support the span.

 

[bp fick]

We've decide to shorten the span to 13'7". I'm going to make another beam to go under the existing beam to support the span.

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:

 

[LD1]

We've decide to shorten the span to 13'7". I'm going to make another beam to go under the existing beam to support the span.

It shouldnt take much more reinforcement if you are only lengthening the origional span by 1'1". Provided you didn't have problems with the existing beam and span of 12'6"

 

[carpenter383]

Something we did once to strenghten a beam was to cut 1/2"out of the sub floor on each side of a wall that was directly above the beam, then we sheeted the wall with osb, letting it go down and tie to the beam.
You would have to notch around your floor joists, not sure if this would be possible for you, but might be worth considering, It would definately add alot of strength. You would have to jam extention any doors in the wall, because of the extra thickness, but that's no biggie.