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Bird Doo Head 12-08-2010 05:08 PM

Main Beam De-Laminating
Hi To All! Hope your days are going well!
I'm new here and find this to be the most informative and helpful site I've ever visited. I've found many great suggestions about all kinds of items.

I searched for posts regarding main beams in houses, with all of their associated problems. I can't seem to find an article that addresses my situation, so I thought I'd post it here.

My house is about 100 years old and the floor construction is of 2 x6 joists (many newly sistered). They are on varying center spacing, mostly about 16". The length of each to the main beam is 9 feet. Some overlap at this beam, some are full 18 foot lengths.

Main Beam Specs: Nominal 2 x 6 lumber (Actual 1 3/4 x 5 3/8- Goofy, Huh?)
There are 3 nailed together. The spacing between columns is: Start to #1 is 4 Inches #1 to #2 is 6' 6" #2 to #3 is 11' 6" #3 to #4 is 3' 10" #4 to End is 6')" At one end is the column to start the beam, the other is a block bump-out from the basement wall. The beam rests on this and the wall.
The columns are steel adjustable (except for #4- that's wood 4x4.) I believe there are footers below the concrete as I can feel a large temperature difference on the slab for 1 foot in each direction from each column base, but I may be wrong. I know the slab is 3" thick, as I've been in there for repairs.

Here's the question: (If I didn't bore you to sleep with the facts and figures above) The beam layers are separating. In the large (11' 6") span, from 6 feet from the post to almost the next post there is a 1/4" gap at the bottom only between the "north" board and the center one. A few more spots along the entire beam have small separations between "north" & center or "south" & center. They vary from a few inches to a foot or more, then close back up.

I also noticed that there is a 1/4" sag centered between supports 2 & 3 (the long span). Just to make it more fun- If I run my hand down the face of the "north" plank, it is convex in this span only. Yikes! (Is that the correct word? It is bowed out.) The others are flat.

It appears to me that the we are asking too much of that beam. Yes, it's been here for many years, but my wife & I must load the house differently than prior owners did, or maybe it is just old and dry & tired!

I used pipe clamps to start (slowly) squeezing the laminations back together, with the intention of bolting through all three. Then I decided to wait and write to you folks for ideas! I would love to put a column & footer in to halve the span, but that would put it smack dab in front of my built in workbench.

Some ideas I though about were to slowly raise the sagging portion (adjustable column on wide plate temporary steel foot) bolt through the beam in several places with carriage bolts & fender washers or plates
AND ...

A) Install a steel angle as a bottom cap for the beam. Plus= Relatively simple. Minus = Cost, How to get it inside the house, Squeaks from movement, Disturbing the original columns, possibly cracking plaster. I would have to install 2 temp support systems, (one on each side) as joists overlap. Would it do any good?

B) Install a steel "U" Channel cap: Plus= I would imagine it would work, cradling the main beam. Minus = Cost, Getting it inside (glass block windows) Squeaks, Moving columns to install versus plaster cracks.

C) Face one side with steel plating. Plus = Seems simple. Minus = Cost & Knowledge of: 1) Can I splice lengths? 2) Can I glue & bolt it or will it squeak? 3) Will it stop working as the thru-bolts holding it work around in their holes for a few months? (Or screws holding it working loose.) 4) Squeaks?

D) Small I-Beam under the existing beam. Plus= Seems like it will work, if I can fasten it so it doesn't kick out. Minus = Head room will be 6 feet, or less. I have to disturb the existing columns, possibly cracking plaster above when I put in the temporary supports. A future buyer will look at it and say "What the heck .."

E) Laminate the beam with plywood. Plus=Fast & least disruptive. Minus=Will it do any good?

F) Having a pro replace the beam. Plus= 2 Minute Job (How long it takes to write a check) Minus = Covering the check I just wrote!

What do all of you think of these "Grand Plans"? Do any of them sound feasible? Do you have any ideas of yours to share? I sure appreciate all of your help on this one. My brain is stuck!


Bondo 12-08-2010 06:09 PM

Ayuh,... I'd put another jackpost under it in the center of the long span, 'n jack it straight...
Then pop a few screws through the beam...
Then go Play... Leave the post in place....

Bud Cline 12-08-2010 11:09 PM

"Bird Doo Head" is the user name you chose to use here and then you expect anyone to offer serious information ??? Good luck.:)

Ron6519 12-08-2010 11:13 PM

This is not the original beam, nor the original posts. Somebody has made some changes down there.
Post some pictures of the issues.

Bird Doo Head 12-09-2010 07:56 AM

Photos Attached- I Hope!
3 Attachment(s)
Bud Cline "Bird Doo Head" is the user name you chose to use here and then you expect anyone to offer serious information ??? Good luck.
It is a just for fun nickname I have. I was sitting on my patio trying to select an E-Mail address for family & friends when a bird dropped some inspiration on my noggin, hence the name. If you have no humor & my nickname bothers you- Just ignore my posts. Simple as That!
Please note that I do sign my postings with my "oh-so-hum-drum life-is-serious" real name.

This is not the original beam, nor the original posts. Somebody has made some changes down there.
Post some pictures of the issues.

Ron, thanks for the reply! I agree that this is not the original beam. I believe the basement was added under the existing house for several reasons: The primary "clues" are: The lumber dimensions are not consistent with 100 years ago wood. They are too close to our, current, nominal sizes. (But still goofy) The second reason is that the top 3 courses of block in my basement are rock-solid concrete and the ones below are cinderblock. I don't think the house was moved into position from another site, just lifted.

I've attached some photos (I think I did it correctly!). The first two show separation, but one is about 1/32" less as I'd started clamping it back together before I thought to write you all and ask for advice. In one you can see what looks like a crack in the center lamination. It actually looks to be (in person versus my amateur photography!) a separate 2" long piece, but 4 feet from there there is a crack in it at a knot. I see no cracks in either face lamination along the entire length.
The third photo illustrates the columns I was describing. You can see the wooden one in the background. I believe I'll add a steel post next to it during the course of these repairs.

Thank you again for responding, Ron. I do hope to solve this without adding a column at my built in workbench. My latest brain storm was a sister of 3/4" plywood on the face of the beam. Then I'd add a piece of steel angle with one leg facing away from the beam. It would be approximately 3x3x1/8" & span column to column. I'd screw it or thru bolt it (or maybe Ramset pin it) to the beam's face near the top, but not touching the floor joists. The hope is that the angle's vertical face will prevent some downward deflection and the leg would help stop sideways deflection. I would through bolt the beam to bring the original plies back together (as far as they will go) before the angle went on. Am I on a good track, or way crazy on this one?

Thanks Again!
Bird D... Oops! I Mean Paul.

Ron6519 12-09-2010 10:19 AM

You can't really guess at this over the internet. It really requires an onsite load calculation and observations.
But offhand, it seems too light weight for the issue. I would lean more to adding a flitch plate or two to the sides of the beam, through bolted with 1/2" carraige bolts. It could be 1/4" or 1/2" plate was needed, but again, only an internet guess.

Bird Doo Head 12-09-2010 12:08 PM

Time To Call In The Pros!
Thank You Ron!
I think you are right in suggesting on-site evaluation. I'd hate to waste time doing "guess" repairs and have it not accomplish the task intended or complicate proper repairs.

I did figure out why the low spot is where it is. Between the posts that are on 11 ft 6" centers is the low spot, at 20 inches "east" of the center of the span.
I measured it all out, did some periscope & drill bit snooping & old photo viewing and came up with:

The second floor has a room where the joists overlap -near room centerline- on a built up beam inside the floor. It's kind of goofy- below the room's floor are the joists. There is a plaster ceiling on the joists up to the beam they rest on. (Old bearing wall?) A few inches below the beam is a second set of joists that go the whole width of the room. They don't touch the top layer at all. There is the lath & plaster ceiling you see from below on that. I'd guess they are there only to hold the "new" plaster.

This 2nd floor (joist holding) beam is resting (west) on the outside wall let-in ledge (balloon construction- no top plate). The beam's east end is resting on an interior 1st floor wall's top plate. That wall is made of 100% studs. There are no gaps, it is one solid mass of studs. The wall is about 30" wide. The wall is parallel to & directly above the basement beam. It spans 2 joists directly where they cross the problem basement beam. One end of this wall is on a joist exactly over the low spot.

Crazy, Huh? (But, I'll bet you've seen crazier.)
Thanks Again!

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