Question about an ibeam used in basement…
Hi everyone.
So I hired a contractor to rebuild 2 basement walls in my basement in November of 2020 (a year ago). To be honest, these “walls” were more or less French Ledges with the original footing 2 feet or so behind the ledges and at shoulder height when standing in the basement. These were showing major signs of movement (bowing) with major water penetration, so I had to do something about it and sadly, I didn’t have a lot of money to work with.
The contractor that I hired ripped the old walls and materials out in about 3 weeks after putting the house up on additional temporary columns, poured new footings at an actual footing level (below the basement slab), reinforced everything with rebar, then stacked up actual CMUs, etc. and also installed an additional sump basin. In this same work, they also removed some of the old load support underneath my kitchen and bathroom areas and replaced that with a 4″ x 4″ x 17 foot long i-beam cross support to support the joists, kitchen and bathroom (see image “ibeam-dimensions-and-span.png“). Thing is, I’m seeing some minor sagging with the beam. I think the span is too far without a center column to support its length. I haven’t placed a column underneath it yet. Should I? I mean, I guess it’s obvious that I should but having some other eyes on this would help me know for sure. I can be a worry wart at times, so I’m not sure if this is something to really worry about or not. I think the max length my ibeam is coded for is about 8 feet, so with this being 17 feet in length, well, it speaks for itself, right? I would’ve said something about this length had I known it might be inadequate, but I mean, I know nothing about home construction let alone, ibeam span values…
I’ve attached a few images to help show what I’m seeing… The “sag” isn’t very obvious. In fact, I think it’s pretty minor, but the image that shows it best is the one titled “Sag-most-visible.png“. (And please excuse the exposed pipes, etc. in my basement–I haven’t been able to tackle that stuff yet. It was all under some of the support dirt that was removed when the new walls were constructed.)
I know it’s sagging at least a little because I put a leveler on each end (North and South ends) of the beam and the bubble isn’t center on each end, but not by much. The level bubble is worst in the “South-Bubble.png” image and even that isn’t that bad. I think at most, it might be maybe an 8th of an inch upward… The “North-Bubble.png” image shows a better level. In fact, it’s basically center and within the “center box lines” (this image isn’t very clear but you can make out the bubble outline if you zoom in).
Am I worrying too much? I’m planning on getting back in touch with the contractor to run this by him and see what he thinks. I was planning on getting back with him about some other things anyway, so I figure I’ll kill 2 birds with one stone…
A little background on the house: it’s an older Midwestern small town stick-built, single level w/ attic home from the 20s / 30s. The original foundation was comprised of old vitrified ceramic block and the ibeam on the North side is inserted into about 3/4″ worth of CMU whereas the South side rests on about 2 or 2.5 feet worth of the older ceramic block and old footing. This beam supports my kitchen and bathroom areas with the most weight likely coming from the kitchen from the refrigerator. Beyond that, I don’t think there’s a lot of weight on that beam besides the home’s construction material, which obviously isn’t something to scoff at. My floors creek–typical of an old home, right?–but as far as actual movement anywhere, I believe the guys that rebuilt the walls fixed any that was happening. I haven’t seen anymore cracks or other indicators in the house like I did before I got them to do their work. And trust me, I’ve been keeping a paranoid set of eyes on things. Things seem okay now.
Any feedback about the beam would be appreciated. Am I being a worry wart?
Replies
Beam seems to be too shallow for the span. I cannot load the full-size images so I'm missing some context. Minor deflection is to be expected - pull a string below the beam's bottom flange from one end to the other. Space it about an inch below the flange at each end, then measure the gap between the string and the bottom flange at various locations. Visually observe what happens to that gap at mid-span when someone walks across the floor above. Ideally it should not vary by more than 1/16".
Good advice CT. Forget the level and use a stringline. If you can jack the beam up to take out the sag and add flitch plates (steel plate) to each side of the beam you will be okay.
@Sawdust_Steve:
Kinda hard to utilize flitch plates on a steel beam....
CT you are right!. I looked at third photo and thought it was a LVL beam
Thanks for the responses you guys. I've had a chat w/ my contractor about this and I'm planning on running this by him when I get him back out to the house sometime in January. In all honesty, I think I was just looking for things to worry about, too, because I slept on it and came back to look at it the next day and felt I was overthinking things a little.
Despite that, I do plan on doing something with it. I'm just not sure what. One thing I want to do is shore up the base the ibeam sits on. On the North end of it, one side of the beam has only 1/2" worth of CMU and on the other side, more towards 3/4". So, one idea I've had is to stack a few more CMUs underneath that side in some sort of decorative way thereby giving a better base that's somewhat aesthetic. (This all assumes that something can't be done to simply insert the beam more into sill plate layer, too, without compromising the sill plate--I hope that makes sense.) As for the other end, it has a much better base to sit on as about 2 entire feet worth is supported by block. The only problem is that it's sitting on the older vitrified ceramic block. From my view, it all looks stable and isn't going anywhere, but in the future, I thought I might try to get with my contractor to remove a certain amount of that to be replaced with the better CMU base, not just for stable support that's better, but also because it would be better looking and prep things for more basement wall work if I ever decide to do it.
Anyway, whenever I get my contractor guy out again, I'm going to see what he says about the minor sag and whether a column might be necessary. Each end of the beam has little wood slice wedges that they used to match the old floor and joist heights that the original support had and he said that if any of the wedges are loose, it likely means that the beam really is sagging and isn't just settled with the above weight (when they lowered everything back down after the walls were replaced). I checked the wedges and they're super-tight: they didn't move an inch. So I think I was just being a worry wart. :)
you should ask your contractor for the stamped engineer's plans that specify a 17' run for that I-beam. Then when he can't, you should ask him how he knows that size beam is sufficient to carry that load. You should go with your first instinct that this looks way too small. Did you have a contract, and what were the terms for this particular part of the work?
Agree with Mikelfion. Is this project being done under a city or town building permit? Or is it being done without a building official's oversight? If it's the latter, you may be liable to correct any deficiencies should the building department become aware of the project. Does your contractor hold a current license to perform this kind of building modification?
Unfortunately your photos are not of adequate resolution to discern what's really in place. It would be helpful to know/see:
- The beam's overall depth and flange width AND the thickness of its flanges.
- Better photos of the steel beam's bearing condition at each end.
- The photos showing the level's bubble should be illuminated from behind so one can easily see its position between the lines. Also the length of the level that you used.
Your photos did not load well - I had to download the first & last in order to enlarge the images. When I do that, they get rather grainy.
There is always a way to make things work to the satisfaction of the various materials strengths, but you may not like the associated costs if the building official were to reject the current state of work as seen in your photos.
[Structural engineer here. Licensed in CT, MA, RI, NY]
No itemized contract on this one, guys... I know, I know... Lesson learned. This was the first time I ever did anything like this but at the time, I didn't have a lot of money to work with someone more credentialed or professional. Being my first time, to say this was a learning experience for me is an understatement. I mean, I had nobody to depend on in any of this except myself, but the caveat is how in my region here in the Midwest, almost nobody does this kind of work anyway and if they do, chances are, they do it only for costs I couldn't afford. The project didn't consist of just the i-beam thing, too. That was involved with a massive undertaking of excavating tons of dirt out from the basement before rebuilding 2 entire sides of the basement with newer block to create actual walls with (what was there before were not real walls but more or less French Ledges with cracking footing at shoulder height about 1-2 feet behind the French Ledges). The work also involved adding new footings, new perimeter drainage, and an additional sump pit...and all for a 1930s-era home, which mean you had to be careful about the other remaining older walls and other construction to avoid any catastrophes while doing the work. Finding someone in my area who is willing to and can do all of that for just $36k? I was lucky to get the guy I had.
There's no question about whether it should've been more professionally done. But the sad fact is that I could've gone down there alone with a shovel and a bad of quikrete and probably improved things--that's how bad it all was before the work was even done with the new walls.
But all that being said, one approach I've been thinking about with this current i-beam situation is simply replace it with one that would be better spec'ed. I'd like to preserve as much head spacing as possible to avoid reducing walkway clearance, but in my mind, the only adequate size I can think of would be an 8-inch beam. (If that rule-of-thumb they claim is best to go by about the width of the beam being multiplied by 2 to give you the max span in feet, that sounds like it would be best, right? Because 8x2 would give me 16' of span, which would be more than enough for that space down there). Thoughts? Are there beefier types of beams that would work for this span that aren't as tall as 8 inches? Like a "plate-like" beam that's thick enough for about 16-17 feet?
First - I have no understanding of what the term 'French Ledges' means in the context of a foundation.
Second - the depth (vertical height) of a beam has the greatest effect on its deflection (sag) under dead & live loads AND on its performance (think 'bounce'). While it may be possible that a steel beam has the 'strength' to span a particular distance, its performance may be like that of a trampoline when someone walks across the floor that it supports.
I think he might mean what in Indiana we called a "Michigan basement."
French Ledge being that it's not a real wall in the sense that the wall block comes all the way up to, say, the joists above (as most real walls in basements, do). Instead, my home's basement was dug out after the home was built. Because of that, the original footers are at shoulder height BEHIND these French Ledges that I keep referring to, which were placed down to wall-off the exposed dirt behind them. They're really nothing more than a facade wall that hides exposed dirt left over from the dig-out and on top of that exposed dirt resting on top of it all is the original home footing. I hope that makes sense. (Maybe my terminology confused it or might be just wrong, but either way, the original "walls" in my basement were more so just facade walls installed from an older dig-out.)
Thanks for explaining the deflection / performance. With my beam, I can't really say that I noticed any bounce anywhere. I do have creeks and little noises like that from my flooring, but I also had a lot of that before the new walls were built, too.
So it sounds like the best course of action now is to see what can be done about swapping out that current 4-inch i-beam in favor of a bigger one as I want to avoid needing more columns to ensure the most amount of walkway space. I think what I'm going to likely do then is get with my contractor and see what he and his team can do about that. I'm hoping I can get maybe an 8-inch beam swapped out with each end being shored up with more CMU-based support. If I can, I think that would be the best approach. I'd hate to think that should cost very much in labor. I'm sure the new beam will be no less than $2k, though... Ugh.
1) do you have a code enforcement requirement or is this guy able to do what he wants? If there is an inspection, you should be there and that would be the opportunity perhaps to have your guy be forced to fix this.
2) I'm in the DC region and the engineer I work with is $200 per hour. It's not onerous to pay $6-800 to make sure your house doesn't collapse.
3) Even if you're winging it, you can find tables in a few minutes on google, and I could see pretty quickly that a W4/13 was pretty weak for that span. Anyway, I digress. You should get a qualified professional to calculate and spec what that structural member ought to be, not the guy who put in that little thing.
4) Now, in the spirit of Christmas, good luck :)
I'm in central Indiana and once spent $100.00 to have a "certified structural engineer" (who graduated from one of our state's most prestigious engineering universities) come out and give me a good bill-of-health and that was before replacing 2 bowing basement walls. And during my initial home inspection back when I was trying to close on this house after the landlord arranged the sale (back when I was originally renting it and had to have it inspected for my loan), the inspector never batted an eyelash at anything...but that was before the i-beam was installed. I say all this because out here, good inspections or engineering assessments are hard to come by.
As for code enforcement, not really. Here where I live, that's loosely enforced but I can definitely make a call to see if I could get the inspector out to my house to see what he thinks. From what I remember seeing, the contractor had a permit to do the work, but in all honesty, I don't know how honest it was as in, I don't know what the contractor said about the work he was doing to know if it was truly copacetic (not to say the man is a bad guy or something, just that I think he errs on the side of expediency rather than quality).
Wolf_22: If you're the one walking across the floor you really wouldn't perceive the 'bounce', as it's not like walking on a trampoline. But someone sitting at a table with a full cup of coffee or glass of water will notice the effect of your walking across the room, as the surface of the liquid will ripple (hopefully minimal) or actually slosh back & forth (NOT a good sign).
Hope your Holidays are enjoyable and perhaps you can forget about this issue for a day or 2 or more.
Thanks for the insights, CT_Yankee. I'll keep it all in mind. I'm thinking in time, I'll get this corrected. Probably not for free (unfortunately). I know the contractor probably could've done a better job with this i-beam thing, but overall, considering everything they DID do with the situation they were working with and the money they charged, I'm okay with it for now. I'm going to make a call to our town's building inspector to see if he can swing by my house to pick his brain about this and see what he says (an idea I basically got from Mikeljon above). I hope I don't shoot myself in the foot by doing this. I mean, I can't see a building inspector somehow forcing me to fix something like this...but I also don't see him trying to force the contractor to come back out for corrections, either. What I do see him doing is providing some passive insights about it and whether he thinks it should be fixed or not. Considering I'm in Indiana--a state not known for impeccable professionalism, especially in the trades--I doubt he'll bat an eyelash at it. But either way, I'm going to give him a call tomorrow and see if he could come by sometime to look at it.
But in all honesty, I'm not really too worried about it. I mean, I don't see it ever giving away into complete failure. I can see an earthquake causing me problems with the beam's placement, but thankfully, the severity of quake I can see being needed to do that isn't one we get very often. So, I think I can live with this situation for a couple years without sweating it very much. (I hope to have the place paid-off in about 4 years then save up for a $50k down-payment to be out of this place in about 8 if possible.)