Basement Main Beam Replacement

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johnbaum

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Hello, I am a new member here but am a long time reviewer of the advice given here and it has helped me out several times. I have what may or may not be a unique situation that I need help with. I just recently purchased a home in West Virginia that was built sometime in the 30's. This home has a basement that was dug inside the homes border foundation. There is a concrete foundation poured about 2 feet beyond the basement walls and the basement walls were not mortered to the top, only to the ground level. There is a sistered 2x10 (Actually measures 2x10 as do all the floor Joists) center beam that is supported by 3 jack posts. The three jack posts are the only center support in the basement.

This area still has no building codes or building inspections. That being said, the work that went into the house, especially the center beam and the joists are not what would be considered acceptable by todays standards. The Center beam that holds the weight of the home was peiced together and fortunately was staggered however in 2 locations the floor joists are hung at one of the intersections of staggared joints. Many of the floorjoists have plywood spacer plates between the joist and the center beam and toenailed in and some were simply toenailed with an inch gap between the joist and center beam. The house is sagging in the middle with doors that won't close and sheetrock that has cracked and pushed out above most of the doors and windows. The Center beam as well as some of the joists have been attacked by termites (Appears to be an old infestation and no live termites found.

I need to know the best way to replace the center beam and rotted floor joists. The support jacks are actually receeding into the centerbeam by as much as an inch on some of them, others seem to be supporting fine.

Is this a job for a pro or can someone with carpentry knowledge make these repairs? What type of center beam would be recommended to make the repair. How would the center beam be removed? I believe that more jacks would be required to support on each side of the center beam with a 4x4 and 2x4's attached to each joist to prevent them from twisting while the center beam is out, Right? I am thinking that to get the center beam out, I would use a sawz all to cut the nails connecting them to the joists and pull it down away from any flooring nails from above. I'm sorry I have no measurements of the length of the beam but it is a small 1000sf or smaller home.

Any advise would be appreciated.
 
Time to call in some pro's on this one.
There's going to have to be some temp walls built to support the floors above while this work is being done. I'd not remove the old floor joist, there nailed into the subflooring from above and it will distroy the flooring above it if you try and remove them. New ones get sistered in from below once the beam is replaced and attached with joist hangers.
There going to have to slightly lift the house just enough to get the old main beam out with hydrolic jacks. No not car jacks just jack leged in place.
The old floor joist will get cut back enough to allow someone to have room to slide out the old beam. I'd replace it with 3, LVL's not reguler lumber.
And no a 4 X 4 is never used to horz. lift anything, it's not strong enough.
Any old house will have termites and powder post bettles and should have been treated long ago, not just looked at to see if you see them. They live inside the wood and underground and most often are never seen untill it's to late.
 
Thanks Joe,

I appreciate the insight. I assume that there will be three LVL's needed to fill the space left from the removal of the original beam and the shoddy workmanship of the original builders or for strength? Are the LVL's strong enough to support the floor without the jack posts currently supporting? Can LVL's be ordered in a tru 2x10 to match the original lumber? I have been checking around here and the local saw mills still make the lumber as was made back then in true 2x10 or 2x4 ect... Wouldn't the LVL need to be the same size as the original floor joist so the the hangers will work properly?

Thanks again for the help.
John
 
Georgia-Pacific GP Lam Laminated Veneer Lumber (LVL)
An LVL is 50 times stonger then milled lumber and can run longer spans with less support from below, but your going to have to do some research to figure that out.
You would use the hangers made for LVL's (there wider) to reattach the old floor joist, and reguler ones to attach any sistered joist if there's room for them, sometimes I've used HD L brackets with the larger holes for lag screws when a hanger will not work.
The new beam will never come out the exact width as the old beam and LVL's only come in two widths. I suggest using the 1-3/4 ones, for one thing there lighter, and it's simpler to lift into place with the small gap you have to work with between the old floor joist.
Before any post are sat in place check for any floor sag, now's the perfect time to use the beam once the floor joist are reattached to lift the floors up before putting the coloums in.
Use lolly coloums or soild steel post with 1/2" steel plates welded to the ends with holes drilled in the plates in 4 places for nails or screws.
Anyplace there's going to be a post there has to be a footing. 24" X 24" X 24" deep. You can not just have them sitting on a 4" thick slab!
 
. . . . Anyplace there's going to be a post there has to be a footing. 24" X 24" X 24" deep. You can not just have them sitting on a 4" thick slab!

Actually, joecaption's suggested footing depth would make it strong enough to support a typical highway bridge pier column. However, most residences don't have 80,000 lb. 18-wheelers driving through them. It would be a rare occasion to have the need for a 2'-thick residential footing, unless you're planning to use very substandard (3-sack?), unreinforced concrete.

Although the IRC (International Residential Code) allows footings as thin as 6" thick, typical residential footings usually range from 8" to 12" thick, depending on applied loads. Soil bearing strength and applied loads are used to determine a footing's required size (area).
 
Drill a hole thru the floor 14" from the center of a post, if you don,t break thru at 6" you have a 30" footing if you do break thru poke a 1/4" steel rod down the hole and see if the footing is lower. If not drill again at 11" and 8" untill you find it.
Evan a great big footing can settle and there is nothing worse than digging up the floor to find a 36" footing and all you needed was taller posts. Bin there done that.
You asked about doing away with posts with a longer beam, by time you get to twenty feet you beam is often 18 to 20" high and a lot more money and footing are that much bigger.
We never see footings more than 10 or 12" deep with 3 or 4 rebar each way.
 
Thanks for all the advise guys, I really appreciate it.

Up here in WV we have some pretty hard packed Clay and Rock. The posts that currently hold the house up are sitting directly on the basement floor. They don't appear to be receeding into the floor, the floor is not cracking and from knowing the previous owners, these posts have been in place for at least over 15 years. The only problem is that the posts are digging into the rotted beam. I was hoping that the span of the basement could be crossed without the use of posts at all to give more useable floor space (wanted to make it a "Man Cave"). If need be though, Posts could be installed and I could cut away the basement floor to pour a footer for them.

The inside of the basement walls measure 22'8" (Again inside measurements) the actual border foundation is approximately 2' outside the basement walls. The basement walls however seem very strong and show no signs of buckeling or water infiltration but are not complete (with courses of block all the way to the floor joist) but blocks could be mortered in place to make it a supporting wall with ease. I guess my question is could an LVL be used to span the 23' basement without any center supports at all? or perhaps say one at 6' coming from the wall in each direction leaving an aproximate 11' gap with no support?
 
It would take an on site engineer to be able to say 100%.
Put there should never be an open area with no support, that section of the house will sag and also but more stress on the beams you do put in there.
 
You can be sure the the posts are on footing, they may have put them in low and put the floor over top. Two post with 11 ft in between sounds good but you will need to install footing for the new location. You do need an engineer to look it over and I would still be drilling holes to see footing size and there is a chance the footing was put in right across the house for wall.
 
Thanks for all the advise guys, I really appreciate it.

Up here in WV we have some pretty hard packed Clay and Rock. The posts that currently hold the house up are sitting directly on the basement floor. They don't appear to be receeding into the floor, the floor is not cracking and from knowing the previous owners, these posts have been in place for at least over 15 years. The only problem is that the posts are digging into the rotted beam. I was hoping that the span of the basement could be crossed without the use of posts at all to give more useable floor space (wanted to make it a "Man Cave"). If need be though, Posts could be installed and I could cut away the basement floor to pour a footer for them.

The inside of the basement walls measure 22'8" (Again inside measurements) the actual border foundation is approximately 2' outside the basement walls. The basement walls however seem very strong and show no signs of buckeling or water infiltration but are not complete (with courses of block all the way to the floor joist) but blocks could be mortered in place to make it a supporting wall with ease. I guess my question is could an LVL be used to span the 23' basement without any center supports at all? or perhaps say one at 6' coming from the wall in each direction leaving an aproximate 11' gap with no support?
Neal, reread the last line of his post. That's what I was replying to.
 
Another idea I had was to place two steel beams across the bottom of the floor joists that spans the width of the house. One on each side of the existing beam to be removed about half way the distance of the floor joists. (See Attachment) I was thinking that using this method I could possibly eliminate the center beam altogether by peicing in material between the joists and securing them together with steel plates. I think that the steel beams may need to be closer together to support the middle but still may afford space enough between them to make a decent sized room. Any idea if this would work? There are a number of steel beam manufactuers available to choose from, one being these folks here, LiteSteelbeam? - Installation Guide

Please keep in mind that the drawing is just to illustrate the idea and the amount of floor joists are not indicative of size.

Thanks again for all the help.
John

Quincy Lane Basement floor.jpg
 
Sounds like a pie in the sky idea, you need to have an on site engineer to speck any of this stuff your thinking about to size it and for what supports your going to need. And you will need a permit on this one.
That one beam would require you to punch out the foundation, add footings on each end and just how do you figure on sliding it in and setting it?
Can it be done yes, but not DIYed.
If you try and DIY this your whole house may suffer.
 
Well and engineer may be cheaper than a crew of Construction workers. No Code here at all. No Permits needed, No inspections needed. I don't believe the foundation would need to be punched rather the beam bolted to the foundation as it would butt up to it and the beam wold be resting on the Basement Wall only 1.5 to 2fr away.

You are probably right, just trying to get ideas and opinions. Wife and I have discussed and we will get a contractor in to see what they say about the whole problem and $$$$. I wanted to have some opinions before any come out so I can at least tell if I get a bunch of BS or straight talk and pricing.

Thanks Again!
John
 
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If you start with contractors, you will have different prices for different solutions, you will end up buying someones b,s.
Start with an engineer, everyone quotes the same job, really easy to sort out the b.s.
 
Ok, spoke to an Engineer/Structural Draftsman and all around handy man kind of guy and he suggested that I construct two temporary beams for temporary support and use several jack posts to hold the floor across the studs and basement walls while the old beam is removed and the LAM beam is installed. He also said that where any of the floor Joists are bad to construct "Boots" out of similar sized lumber (Local saw mill true 2x10) and hang all joists to the LAM Beam with Joist hangers. He said that once the floor joists are level and attached to the LAM Beam there will be no deflection and that the LAM Beam would not require any support and will clearspan the width of the basement. He seemed quite confident and had no reason to BS me because he is not a contractor rather a family friend. Does this seem to you guys like sound advice?

Quincy Lane Basement floor.jpg
 
You didn't say how high the beam is. At twenty some feet it would have to be close to 20" high. I would suggest you put a footing and post right beside the stair case. Now your beams are about 7 and 14 ft and if you put another post at the short foundation wall your actual span is only about 12 ft. That would bring your beem down to 10 or 12" depending on number of plys. I would go full length for repairing floor joists. Boots you call them do work but drilling holes up there is a treat.
 
From the Basement floor to the bottom of the beam and floor joists is about 7ft. Not real sure what you mean by "how high the beam is. At twenty some feet it would have to be close to 20" high." The basement floor wall to wall is a little over 22ft 8in wide and then the beam itself continues about another foot and a half outside the basement walls and rests on the foundation.

So instead of the "Boots" you recommend removing the entire old joist and putting a new one in it's place or sistering and leaving the old joist there?

Thanks Again for the advice!
John
 
Now go back and reread my first reply to your first post, that's exactly what I suggested that you do.
We do this type work alot when working on older houses.
Forget the "boots" just sister a new full length floor joist, it's never a good idea to remove an old floor joist, it will mess up the floors above it when you try to pull it out.
And just one LVL is not going to cut it, any real lumber yard that sells LVL's or even contacting the manufacture directly can speck out the width, thickness and number needed for that span.
 
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