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I went to see a steel beam in a 35 yr old residential house today that my customer fears is lifting the centre of the house up. It is clear that the centre of the house, the full length, is higher than the outside walls by about 3/4″ to an inch. I looked for signs of structural changes in the poured concrete foundation walls and in the concrete basement floor. Nothing apparent. I checked to see if the beam was straight or crowned, it was straight. I took a quick look at the floor joist’s to see if they were seriously bellied,( suggesting the crowns may not have been placed up ) looks fine. The only other symptom is a crack in the living room ceiling parallel to the crown in the floor and also dead centre in the house.
Having said all this, my questions are as follows,
1. Has anyone out there seen similar situations, and what was the cause and ultimate solution?
2. ( IF ) you were to consider lowering the jack posts, over what period of time would you do it and in approx. what incriments.
My advice to cutomers with concerns like this one is to always consult an engineer to be sure there insn’t something I’ve missed and to give them peace of mind. I am not a house inspector or a civil engineer, just a contractor, and human at that.
I will take the time now to thank all who respond, for their time and expertise.
Best to all…SteveM
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SteveM
Joseph Fusco
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Dear Steve,
What an interesting problem. Is the steel beam in the first floor? or is it in the secnod floor, where the outside walls may have had the chance to dry and shrink. Have you acutally taken a builder's level (transit) and shot the floor? How wide is the building? While you are shooting the floor, with the builder's level, shoot the ceiling to see what it has done. In most of the log homes we build we place screw jacks under posts and in places to allow us to lower floors and entire levels of buildings to accomidate the logs shrinking. Would something like that work for you? My experience is that if you can lower the beam the house and floor will not immediately come down with the beam. It will come down but it may take it a few days. Chances of having some drywall cracks is pretty good. Also keep an eye on the plumbing connections including gas. I would not lower the beam by more than .25" to .375" at a time. You may question the clients to see just how important that crown is. Can they live with it? If the house is 30' wide than it would be out of level 3/4" in 15' ? for a 35 year old house is that so bad? Hope this helps. And let us know how it turns out.
regards,
Dormer
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I ran into the opposite problem once in a house. There was a half a-- 2 x 3 wall under a bearing beam/wall in a house. The house was 24' deep and we talked of crown moulding until I found the center of the room at least 1.5" lower than the corners. I guess it happened so slowly that the plaster went with the flow, as it was in really good condition.
*Is it possible that the house was simply built that way?Wouldn't be the first time.If the entire lenght of the steel beam is high, the beam pockets would have a gap on the bottom if it would have raised or the foundation lowered. The only place on earth, that I know of, where things go up is in a small part of Ottawa East, in Canada, where their is a shale formation that has a bacteria in it and is called expanding shale. When it is exposed to air, it starts to disintegrate and actually lifts, buildings.When we build in this area, we have to cover the exposed shale, immediately with a concrete mud slab, and then we can continue in the conventional manner.Just a bit a trivia, fyi.If for some unknown reason, the gap was caused by a settling, dropping it into place for a small amount like 3/4" can be done in one shot, as long as pipes are loose. With all the nailing set, it might take a while for the house to settle though...
*If the house wasn't built that way maybe it may be the same problem I had on a place I built about 10 years ago. The perimeter of the house settled but the center of the house did not. This left the center about 3/4 - 1" high. Since it was on sandy soil at first we thought the displacement was caused by frost heaving.But later we decided the foundation sub hadn't followed the plan and thus the perimeter settled. What was remarkable was the almost level settling.We fixed the problem by rebuilding the center beam supports to lower the interior structure but it sure was a pain. From what I've been able to gather if the problem is caused by soil heaving or by foundation settling fixes, if possible, are highly individualized results of creative engineering and construction. Most times I'm aware of the owners just live with the problem until the movement either stops on its' own or the structure is no longer useable.
*IF the beam is supported on each end, and has two columns under it, making it a three span beam, the deflection of this beam in the center span could be up, not down. Need some more info but this is one possibility.
*Could be several things. 1. The outside perimeter might have settled a fraction of an inch due to damp soil, and was so well reinforced, no cracks developed. The interior footings were oversized compared to the others and did not settle.2. The rim joist and floor joists were made of green wood and shrunk, while the center beam was attached differently and shrinkage was not a problem there.3. Somebody goofed and forgot to allow for the thickness of the plywood flooring when setting the beam height and got it off exactly 3/4".4. Somebody expected the beam to settle and built it 3/4" high, but it didn't settle.5. Murphy's law.6. Hydrostatic pressure from wet soil or expansive clay is pushing the floor up in the center. Not very likely.7. Your customer, the owner of the house is a teacher, surveyor/engineer, retired military officer, or lawyer, and expects everything to be "perfect" and precise or there will be hell.
*After reading the post from above I think you guy's covered it all. I'm couris about how the measurement was taken
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I went to see a steel beam in a 35 yr old residential house today that my customer fears is lifting the centre of the house up. It is clear that the centre of the house, the full length, is higher than the outside walls by about 3/4" to an inch. I looked for signs of structural changes in the poured concrete foundation walls and in the concrete basement floor. Nothing apparent. I checked to see if the beam was straight or crowned, it was straight. I took a quick look at the floor joist's to see if they were seriously bellied,( suggesting the crowns may not have been placed up ) looks fine. The only other symptom is a crack in the living room ceiling parallel to the crown in the floor and also dead centre in the house.
Having said all this, my questions are as follows,
1. Has anyone out there seen similar situations, and what was the cause and ultimate solution?
2. ( IF ) you were to consider lowering the jack posts, over what period of time would you do it and in approx. what incriments.
My advice to cutomers with concerns like this one is to always consult an engineer to be sure there insn't something I've missed and to give them peace of mind. I am not a house inspector or a civil engineer, just a contractor, and human at that.
I will take the time now to thank all who respond, for their time and expertise.
Best to all...SteveM