Calling all structural engineers......

[Big_Boy_4005]

This may be slightly off topic, but because it is in my trainroom I feel that it qualifies. Here's the situation:

Five years ago I played general contractor and built the house that I live in. For the most part I am very happy with the results. There are a few minor problems, but none too serious. What I am about to describe is by far the worst, and slightly worrysome.

The house is 40 feet wide, as such there needed to be some center support for the main floor. The roof places no load on the floor, as it is supported entirely by the outside walls.

If you look closely you can see 3 support columns which hold up 2 microlam beams. The problem is with the one closest to the camera.



When the time came to install the beams, we discovered that they were not exactly the same height. Furthermore, the support columns were about an inch too tall, even at their shortest adjustment. It was decided to slightly notch the beams, and solve both problems at once, rather than incur any delay. The carpenters inserted some shims, which they felt were necessary at the time. Keep in mind that there was no load to speak of at the time of construction.

Now 5 years later, with the house fully loaded, the situation has changed. The column is no longer plumb. It has migrated 1/2 an inch. My theory is that the shims are mostly to blame.



Here are some closeups of the actual situation.



The photo above shows the problem most clearly. If left unchecked, I am worried that eventually the column will migrate to the point of catastrophic failure.



In this photo you can see that the lag bolts used to secure the beams to the top of the column are beginning to split out and rupture the beam.



Here you can see the shims. The steel plate that the beams rest on is deformed by their presence.



What to do?

Here's my plan, rent two 10 ton floor jacks and place them next to the bad column. Secure one end of a cable from a comealong to the beam, and the other end to a floor joist. Slowly and carefully pull the beam and column back to plumb while carrying minimal weight on the jack. Once straightened, use the jack to remove all the weight from the column. Remove the shims!!!!

Some kind of plate, wood or steel will need to be bolted to the beams on both sides, thus repairing the rupture. By using wood, this would allow the top plate of the column to be turned 90 degrees, and refastened into new wood. I just happen to have some cutoffs from the construction.

That's my problem, and that's my plan. Any ideas or comments?

I'm still trying to figure out a method of bracing this repair so it doesn't happen again. The main problem is the duct work is right up against the beam on both sides.

I can't fini***he benchwork until this is resolved.[:(]

[Anonymous]

My advice - get some contractors in there to check it out ASAP!!!!

Did I mention ASAP?

A friend of mine had some suspect looking beams, etc. in his house after adding a second story. One night he and his wife were going to bed, and heard some very loud cracking. The house was trying to fall apart. Somehow he wedged some beams in there temporarily. SCARY!!!!

Don't try to do it yourself - get some experts in there. Get 4, 5, or 6 contractors in there to check it out, and then you be the judge of the most honest/knowledgable, etc.

Get on this man, or your layout could be the least of your problems.

That bulging area of wood is a sign it's seeing some major load that it shouldn't be seeing.

Did I mention ASAP???

(only sounding so rude because this could be a very urgent situation).

And no, I'm not a contractor, but a mechanical engineer. That wood does not look good.

Also - your plan does not sound like it fixes the problem. It sounds like you're going to rip a bloody bandaid off of a wound and replace it with a new bandaid. It's time to fix the situation properly, not just reset your previous problem.

Disclaimer: Just talking from the basis of common sense and being a mechanical engineer. I don't know jack about house construction.

[Big_Boy_4005]

Thanks for your input. I don't think you are being rude, just genuinely concerned. Though I don't have an engineering degree, I do have a lot of construction experience. There 2 parts to this problem, getting it straight, and keeping it straight. Getting it straight is easy, keeping it straight is a little trickier because of the ductwork.

Load wants to go straight down. Those shims are causing it to want to kick out. That column carries the load for 240 square feet of floor, most of which is empty space, fortunately. The column is rated for 34,000 pounds which is way more than the weight of the floor, walls and furinture in that part of the house.

The reason the wood looks so bad on the one side is because of the lag bolts which hold the top of the column. They were installed badly, and combined with the sideway force of the shims, have caused one of the 2 microlams to bulge. The other one is just fine. Because the beam is over 40 feet long, it had to be assembled in sections. The bad spot is at the seam on one side, where the other side is not seamed, the joints are staggered.

I originally had my plan reviewed by an engineer, and the building inspector approved it based on the engineer's certification.

The trick is to come up with a brace that will disallow the beam and column from ever going out of plumb again, once it has been straightened.

Your friend's problem sounds much more serious, as he was adding to an existing structure, and overloaded it.

[Anonymous]

Nasty, Nasty!!! .......

I would immediately seek professional help. There is probably a fix that won't be too bad. Don't do this yourself. The loads here are tremendous.

[Virginian]

Man, that's ugly. I'm a mechanical engineer, but I figure if you can design a machine element, what the heck. And, I wouldn't get a regular contractor myself. I guarantee you you will get ten suggestions using wood one way or another as opposed to any other method. Wood does have limitations, as you have found out. I would employ a fix using much stronger materials. I think you have 3 problems, getting it straight, keeping it straight, and repairing a damaged section of a major load carrying beam.
I would get the two jacks and unload the joint as you said. Then I would get a proper length support post, in fact I would get one 1-1/2" shorter and get a 1" steel top plate adder made up. The existing top plate is bent, and that is bad, concentrating the load on the wood. Should have never notched those beams my man. THAT is a no-no, and that beam is definitely carrying a LOAD. Then get a 1/2" plate 18" long, the width of the beam. Drill and tap holes to match the bolt pattern of the top of the post. Drill 4 holes on each end, properly spaced, 7/16" for 3/8 lag bolts up into the beam, or 9/16" for 1/2". Clean up that notch, and fill it with a properly cut wood block, epoxied in place. PRE-DRILL for lag bolts because they will split the h*ll out of wood. Bolt the plate to the beam, and then bolt the post to the plate. If you want to go overboard, get some 1/2" by 18" by 2/3 beam height plates made up, drill about 8 holes in them zig zagged parallel with the bottom edge about 3" up, and thru drill the beam and then then thru bolt both plates to the beam so that they extend 1/2" below the beam, boxing in the post top.
The house may fall down, but that joint will still be there. I would go back and do something to the other two posts too. It has given you a hint, take it. You could probably cut all my thicknesses in half, but I allow for possible errors and overcompensate. Good luck.

[Anonymous]

QUOTE: Originally posted by Big_Boy_4005

Thanks for your input. I don't think you are being rude, just genuinely concerned. Though I don't have an engineering degree, I do have a lot of construction experience. There 2 parts to this problem, getting it straight, and keeping it straight. Getting it straight is easy, keeping it straight is a little trickier because of the ductwork.

i may be a little young so i was wondering ...
could you move the colum ith other supots holding it (jacks) and put a slaller metal bar down into the ground and do the same at the top???[?][?][?]

[Pruitt]

I'm a PE and structural engineer. My advice - Go back to the engineer that approved your plan. He would have the best chance of determining the problem, and the best chance of designing the proper fix for it.

Meanwhile, here's my assessment -

The plates at the top (and bottom) of the column will take only a small amount of load before plastically deforming (bending and taking a permanent set, as the top one clearly has in this case). It appears from the photos that one beam is continuous over the column, while the other one is actually two beams butted end-to-end at the column, and therein lies your problem.

The deflections and bending of the continuous beam member is very different than the bending and deflections of the split beam members at the column. This makes the entire joint somewhat unstable. Over time, as the loading in the joint loads cycle (from someone walking across the floor, for example) the load is transferring from the beam into the column asymmetrically, making the column "walk" to one side or the other (since the beam is attached to the floor and cannot walk).

If your plan showed the beam the way it was built (with one side continuous across the column and the other side butted members), then HE is responsible for approving the faulty design, and you may be able to make him pay for repairs. At the very least you should notify the State Board of Registration for PEs in your state of the defective design he approved (even if it was your design. It may prove sligtly embarrassing for you, but he should have KNOWN this was a faulty design and told you to correct it). If the plan didn't show the assymetrical beam construction at that point, he is not liable for the failing joint.

How to repair:

1. Measure that notch, and get a 1 1/2 to 2 inch thich flat steel bar (good old A36 structural steel will suffice) to fit. The bar should be as long as the notch, and the same width. Any steel fabricator can make this for you. Have them prime the bar to prevent corrosion.

2. Support the beam on either side of the column (with adjustable-length lally columns), and remove the permanent column if possible. If it's embedded in the floor, you can re-use it, but you'll have to cut the top off at the appropriate height to match the bar you made in step 1 when it's installed. Cutting it won't be easy.

3. Get a new column, or cut the existing one to the height needed to support the beam when the bar from step 1 is fitted into the notch. Set the column into place.

4. Add a feature to the bar from step 1 that will prevent the column from slipping on the surface of the bar. This will vary depending on the final configuration of the top of the column. If the column has a center post, a 1/4 inch depression of appropriate diameter drilled into the bar will work - the post will drop into the recess when installed. If it has a top plate like the one in place now, drill matching holes in the bar (time consuming but not difficult, if you have access to a drill press). Just make sure whatever you come up with is sound.

5. LIFT the beam slightly using the adjustable lally columns (one or two turns of the scres maximum - you don't want to crack the drywall above), and slip the insert into the notch over the column. Set the beam back down onto the column.

6. Do what Virginian said regarding side plate, but 1/4" thick should suffice, but make them 36" long (you will be effectively turning the butt-joint beam into a semi-continuous beam this way). These plates should also be primed. When you install them, they should be flush with the bottom of the beam, so that the Step 1 bar is captured between the two plates. Bolt through about two inches away from the bar on each end of it, and about two inches above the lower edge of the beam. Make these small fasteners - say about 1/4" diameter through bolts. You don't want to take out too much of your beam's most heavily loaded fibers! For other bolts, stay 3" or more from the edge and use 3/8 to 9/16 diameter bolts. No more walking column!

Remember this is all based on your photos, and if I read them wrong, this repair may need tweaking. But I think this will permanently solve your problem.

Any questions, feel free to e-mail me. You'll find my e-mail on my web site.

Good luck!

[Anonymous]

Elliott:
I'm an Electrical Engineer and the above solutions sound good but I don't think that you should attempt this repair yourself. You have a structural problem that will affect a large part of your house. I'd call a local architect and get him to recommend a structural engineer that deals in home construction. Suggest these ideas to him and let him decide which is the best as he'll be able to look at the problem up close. Then get a contractor to do the work.

I'd also get the engineer to look at the other columns and see what shape they are in.

You've got a serious problem, don't wait to long as it'll be easier to fix now then when the beams are laying on the basement floor with a caved in house.

Bob

[Leon Silverman]

There is a reason why professional engineers (P.E.) are licensed. This is so they can be sued and have their license revoked if they screw-up. Examples of lost licenses include the St. Louis Hilton Walkway collapse and the parking lot collapse in Atlantic City .
You said the inspector approved your original plan based on an engineer's certification. He is the person who should be providing you with a solution. I suspect that an attorney will also advise you that he is liable for the repair cost.
An applicant for a P E exam will lose points if he designs a structure that is too weak, not if the structure is over designed.
Working for the federal government, I do not have to be licensed, but your problem shows evidence of bulkling due to over stressing. The three supports should have added intermediate supports for a total of five supports. It probably wouldn't hurt to add diagonal braces between the bottom of the beam and junction between an adjacent floor beam and the ceiling. Adding horizontal braces, you would now have a construction similar to a Warren Truss bridge.

B.S.M.E.

[nslakediv]

problem #1~ column is not centered on post. problem#2~ a beam is designed to be 1 unit, meaning those 2 units need to be mechaniclly fastened, ie, 3/8 or 1/2 lag bolts every 24" minimum 32" maximum. my guess is the 2 beams when loaded are rocking back and forth ever so slightly. the contractor should of glued them together with a good sub floor glue anf lagged together. original engineer should of stated this in plans. some is liable for repairs. be careful jacking beam as concrete under temporary posts might not support load, usually a beam pad is poured under floor to support post load. usually a 12"~16" pad. better call a qualified contractor before reacting even if he doesnt do the job he can at least give sound advice and pass him a $100 for his troubles. you sound like me, enough expierence to do repair, but you should air on the side of caution.

[Anonymous]

Leon, are you referring to the Hiatt Regency collapse in Kansas City? I had not heard about a Hilton walkway problem in St. Louis.

Ed

[davekelly]

I agree with the above. The notch and the butt joining of the two beams are most likely a major cause of the problem. I do think that you should spread your concern a little and have a professional structural engineer have a looksee over all of the supports in your house. Fixing the one problem may result in a problem cropping up somewhere else and it is a lot easier to solve all problems and potential problems at the same time rather than running from one to another.

Also, don't be afraid to "over engineer" the solution. You'll sleep better at night. (my ex-wife used to joke that anything I made would survive a nuclear attack - well worth the maybe 10 percent increase in cost).

As for finding someone legally liable for the problems. (I am an attorney with a ME undergrad degree). Yes, there is the possibility that the PE you had first could be liable. If so, he can be found liable for repairs. You need to keep in mind a few things, however. Such litigation could prove to be expensive. In order to prove the PE negligent you would have to find an "expert witness", another PE that is willing to testify that what your PE did was not in conformance of what a PE should have done. You many find that it is impossible to find a local PE willing to do that and will have to pay someone outside your area to review the work. Your expert may want to examine the structure before any repair work is done which will allow him to see the problem first hand and take necessary measurements. This of course will delay the time needed to make repairs. There is one other downside which may save the original PE. It seems like the notch that was cut was not in the original plan. The other side will most likely claim that it was the notch that was the cause of the problem. They will also most likely argue that the notches were cut, not based on any engineering analysis, but rather as a way to save a couple hundred dollars of obtaining columns the correct length and that had he known about the notch would have never signed off on the plan. The crux is that the supports were not made in conformance to the plan. The other problem I see occurring is that you acted as the general contractor and took part in the decision to modify the plan by notching the wood etc. Thus, there is the possibility that the PE and the contractor that did the work would be found only partially liable, with some percentage of the liability found against you as the general contractor. Should you decide to pursue this legally, I would suggest that you contact a couple of attorneys well experienced in contruction issues to get their opinions.

Legal issues aside, the most important thing is to get the supports fixed and fixed NOW. Finding legal liability and getting repairs paid for by someone else means nothing should someone get injured.

[Leon Silverman]

Yes. The important issue is that the professional Engineer was no longer a professional Engineer. That collapse was quite a few years ago. The Atlantic City collapse is relatively recent.

[davekelly]

Leon,

History Channel has an intersting series called "Engineering Disasters." One of the episodes included the skywalk collapse. Very interesting.

[Big_Boy_4005]

QUOTE: Originally posted by Brunton

I'm a PE and structural engineer. My advice - Go back to the engineer that approved your plan. He would have the best chance of determining the problem, and the best chance of designing the proper fix for it.

Meanwhile, here's my assessment -

The plates at the top (and bottom) of the column will take only a small amount of load before plastically deforming (bending and taking a permanent set, as the top one clearly has in this case). It appears from the photos that one beam is continuous over the column, while the other one is actually two beams butted end-to-end at the column, and therein lies your problem.

The deflections and bending of the continuous beam member is very different than the bending and deflections of the split beam members at the column. This makes the entire joint somewhat unstable. Over time, as the loading in the joint loads cycle (from someone walking across the floor, for example) the load is transferring from the beam into the column asymmetrically, making the column "walk" to one side or the other (since the beam is attached to the floor and cannot walk).

If your plan showed the beam the way it was built (with one side continuous across the column and the other side butted members), then HE is responsible for approving the faulty design, and you may be able to make him pay for repairs. At the very least you should notify the State Board of Registration for PEs in your state of the defective design he approved (even if it was your design. It may prove sligtly embarrassing for you, but he should have KNOWN this was a faulty design and told you to correct it). If the plan didn't show the assymetrical beam construction at that point, he is not liable for the failing joint.

How to repair:

1. Measure that notch, and get a 1 1/2 to 2 inch thich flat steel bar (good old A36 structural steel will suffice) to fit. The bar should be as long as the notch, and the same width. Any steel fabricator can make this for you. Have them prime the bar to prevent corrosion.

2. Support the beam on either side of the column (with adjustable-length lally columns), and remove the permanent column if possible. If it's embedded in the floor, you can re-use it, but you'll have to cut the top off at the appropriate height to match the bar you made in step 1 when it's installed. Cutting it won't be easy.

3. Get a new column, or cut the existing one to the height needed to support the beam when the bar from step 1 is fitted into the notch. Set the column into place.

4. Add a feature to the bar from step 1 that will prevent the column from slipping on the surface of the bar. This will vary depending on the final configuration of the top of the column. If the column has a center post, a 1/4 inch depression of appropriate diameter drilled into the bar will work - the post will drop into the recess when installed. If it has a top plate like the one in place now, drill matching holes in the bar (time consuming but not difficult, if you have access to a drill press). Just make sure whatever you come up with is sound.

5. LIFT the beam slightly using the adjustable lally columns (one or two turns of the scres maximum - you don't want to crack the drywall above), and slip the insert into the notch over the column. Set the beam back down onto the column.

6. Do what Virginian said regarding side plate, but 1/4" thick should suffice, but make them 36" long (you will be effectively turning the butt-joint beam into a semi-continuous beam this way). These plates should also be primed. When you install them, they should be flush with the bottom of the beam, so that the Step 1 bar is captured between the two plates. Bolt through about two inches away from the bar on each end of it, and about two inches above the lower edge of the beam. Make these small fasteners - say about 1/4" diameter through bolts. You don't want to take out too much of your beam's most heavily loaded fibers! For other bolts, stay 3" or more from the edge and use 3/8 to 9/16 diameter bolts. No more walking column!

Remember this is all based on your photos, and if I read them wrong, this repair may need tweaking. But I think this will permanently solve your problem.

Any questions, feel free to e-mail me. You'll find my e-mail on my web site.

Good luck!

Mark, I like what you and Virginian have said the most. I think you are right about the "walking" effect. This floor has a lot of bounce due to the long spans, and lack of cross bracing between the joists.

I'm not really looking to place blame, just fix the problem, and move on with the least hassle and cost. I'm not convinced that the design was so bad, I see this as more of an execution problem. Things could definately have been done better. Keep in mind that this problem is confined to about a 10 foot section of a 40+ foot beam, and only one of three columns is involved.

[Anonymous]

People are all writing books about what to do. What you have said is quite good. Take two 50 ton adjustable jacks on each side and jack them up to hold the support of that beam. But get a piece of steel that will wrap around the beam so that the post will not drive into the wood. That sounds like a plan to me.

[MidlandPacific]

QUOTE: History Channel has an intersting series called "Engineering Disasters." One of the episodes included the skywalk collapse. Very interesting

If you're interested in structural failure, here's some very interesting stuff on the Tay Bridge in Scotland, which collapsed in a storm while a train was crossing it in 1879.

http://www.open2.net/forensic_engineering/riddle/riddle_01.htm

http://materials.open.ac.uk/about_us/tay_bridge.htm#paper

www.technologystudent.com/struct1/taybrd2.htm

[rrinker]

I have to say, as an electircla engineer and not a mechanical engineer, that that just doesn't look safe to me. Lots of good suggestions for repair, but definitely have a certified professional look at it first.
Talk of holding the original certifying engineer liable are all well and good - but did this engineer also approve of cutting the notch int he beam? Those notches SEVERELY impacted the load-bearing capacity of that beam.
The whole thing looks rather light to support a 40' span but I'm used to looking at my house, which was modular. The front half and back half each have a full 3-beam laminate support beam, so downt he middle of my 50' basement is a beam made up of SIX layers of wood instead of 3.

--Randy

[Virginian]

Sorry I didn't mention this earlier. Just replace the whole dam* beam with a pre-stressed steel wide flange and you won't need any columns at all. :-) Getting it in may be tough.
Or, you could erect a steel 'A' frame over the entire house, run a properly sized plate girder over the beam line, and drill and fish support cable down thru the bearing walls and also eliminate all the columns. As to running the cables down, turn off the electricity first! This method could also provide excellent lightning protection.
Seriously, I'd say Brunton's qualifications are pretty fair. If you need to build a boiler to heat the neighborhood give me a call. :-) $250 an hour ($150 with a full liability waiver).