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Some background: previous owners poured a new foundation and moved the house over to the new basement about 14 year ago.

I've been in the house about 8 years and just noticed today while starting to re-do our basement that one of the main beams is resting on an angle iron because it was too short to reach the other end of the foundation.

I have 2 main beams in the house. I'm not sure if that makes this OK. What can I do here? This seems insane. How could anyone think this was the right thing to do?

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enter image description here

FreeMan
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Christopher C
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    The cheapest would probably build a footing under it(structural engineer job) and place a post. – crip659 Jan 28 '24 at 21:22
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    Are there epoxied anchors, wedge anchors, etc. on the opposite side to stop it from rolling down at least? Even then, that's still a problem. – popham Jan 28 '24 at 21:25
  • @crip659, that beam is all shear at the end there. You could rotate that angle by 90 degrees and fasten it along the length of the beam (lag screws from below), cantilevering the angle on top of that block. Add a symmetric one on the other side, cutting the steel to avoid overlap. – popham Jan 28 '24 at 21:42
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    The worst part is when someone does something like that, everything they did now must be examined. – whatsisname Jan 28 '24 at 23:20
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    Thanks @crip659 - most likely the direction we will go. Calling an engineer tomorrow morning. – Christopher C Jan 29 '24 at 01:18
  • @popham sadly no anchors at all - really ridiculous. How this passed inspection when they moved the house over is really beyond me. pure incompetence. – Christopher C Jan 29 '24 at 01:19
  • What does the far end of the beam look like? Is it close up against the face of the pocket, which would make the whole thing an alignment issue? Even so those pockets are pretty shallow for the job... – Mark Morgan Lloyd Jan 29 '24 at 07:44
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    It's astonishing what people come up with. – Peter - Reinstate Monica Jan 29 '24 at 10:26
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    No fasteners? If my eyes are seeing this right, the 4x4 is a fulcrum, the bottom of the iron is a lever, the beam is sitting entirely outside any vertical support, and the 2x4 and vertical part of the iron are butting against the end of the beam to prevent the thing from rotating? And maybe @popham can confirm my amateur analysis but the result is the load of the beam is significantly outwards on the wall rather than down on the foundation? – jay613 Jan 29 '24 at 16:58
  • @jay613, in a frictionless world, that connection is unstable. The very inside edge of the wall where the block bears is the hinge location for the collapse mechanism. If you draw a circle centered at the hinge with radius out at the beam's bearing location, that's the trajectory of the block's bearing location during collapse. You can see that the collapse mechanism requires horizontal sliding at the block to beam interface. Friction there is stabilizing the block with a horizontal load that pushes out on the wall. The steel is interesting too, like you said. Rube Goldberg's house. – popham Jan 29 '24 at 17:38
  • @popham thanks. I was thinking more of a Coyote construction. Acme. :) – jay613 Jan 29 '24 at 18:08
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    Nice construction. It holds because the more load on the beam the more friction generated by the force so there's always enough. Until an earthquake hits and it suddenly has no integrity. – Joshua Jan 29 '24 at 18:12
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    @Joshua, I found a master's thesis written on this friction: https://www.diva-portal.org/smash/get/diva2:729796/FULLTEXT01.pdf. After I stopped laughing about the topic choice, there's actually some useful stuff in there. For 1" of eccentricity, I get a minimum μ = 1/3.5 = 0.29. Guestimating about 7.5 MPa of bearing pressure, Figure 4.5 is terrifying (funny how a situation like this can convert such a dumb thesis into an interesting read). Thank God for mill scale. Otherwise I think that house is rubble. The safety factor of 2 against imminent collapse probably cut it a little close. – popham Jan 29 '24 at 19:23
  • That beam looks like it is held up by positive thinking and prayers.... I suspect that house was not inspected. – Questor Jan 29 '24 at 19:42
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    It looks like the bottom wooden block has been thinking about splitting. If it did it would all collapse instantly. It's lasted 14 years BUT knowing how Murphy works, adding an ACRO JACK while the engineer prognosticates may be wise. – Russell McMahon Jan 30 '24 at 00:24
  • @RussellMcMahon the jack makes a lot of sense, but perhaps as piece of mind and not taking much load. Seems that friction is helping this janky setup to work, taking much load on props could reduce the friction and then its more vulnerable. – Criggie Jan 30 '24 at 01:22
  • Just a follow up on this - this weekends project is to jackhammer the concrete floor and install a new concrete footing towards the end of the beam, and then installing jackpost to support. The somewhat good news is the beam is currently and still level considering all of this. – Christopher C Jan 31 '24 at 01:04
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    @Criggie Great point criggie - i am planning to install a jackpost on a new footing but am aiming to tighten it to the beam just enough so that its stable and to reduce minor load – Christopher C Jan 31 '24 at 01:51
  • @Christopher C, you need to stabilize that beam before creating a bunch of vibration around it. From what I could see on your first image, it seems like the joists span all the way across the good beam to overlap the joists at the bad beam. If there are nails between the overlapped joists like there ought to be, then there's a bit of safety from those fasteners. If there's an overlap at the good beam also, though, then you'll be in a very hazardous situation down there. Also be sure that whatever you use for shoring has adequate strength by itself to hold up the whole mess. – popham Feb 02 '24 at 08:05
  • @Christopher C, if you're forgoing an engineer, I can walk you through figuring out the loads, sizing a column, and sizing a footing. Section R507 in the IRC has some spread footing details for decks to give you an idea of about what size you need. The steel angles detail from my answer below can get you there for under 100 USD and without the jack hammering, digging, etc. if you wanted to pursue that instead. – popham Feb 02 '24 at 08:11

1 Answers1

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That's a job for a local engineer. He'll need to figure out the demand on that connection based on whatever is going on above its joists (load bearing walls, columns, etc.). He'll probably extend the beam by 3" or 4" with lag screws and a chunk of steel or wood. A chunk of 4x6 lumber sounds easiest for installation if it has the strength, but that could be suboptimal if you want to finish the space later.

Throwing two chunks of 2'-0" L3x2x3/8 steel angle at it (one chunk on each side of the beam), a 10,000# strength is easily obtainable with correct detailing. L3x2x1/4 actually works for the 10,000#, but it's close enough that I would spend the extra 10 USD. I can't say if 10,000# strength is enough, but supposing it is, my biggest worry would be getting adequate quality for lag screw installations (and, if you're stuck with Hem-Fir or SPF, getting sufficient bearing capacity for the steel on top of the wall's 4x4). As insurance against poor quality, I would want a couple bolts plus plate washers through the beam's plies in the neighborhood of critical lag screws.

That 10,000# is an Allowable Stress Design number, where you would compare it directly with the load derived from dead load plus live load (and hopefully no additional loads from the roof, for instance). Optimistically, the check is just Area×(10psf + 40psf) ≤ 10,000#. There's an alternative design framework called Load Resistance Factor Design that has a higher strength (and higher demands) to reach similar designs in your case, otherwise I wouldn't bother qualifying the 10,000# as an Allowable Stress Design number.

If you're interested in where the 10,000# came from: https://i.stack.imgur.com/FFBYy.jpg

popham
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