Time to move the shop (chicken little)?
My shop is in a 9 yr old small commercial bldg. I’m on the 2nd floor, 1000 sq ft, and below me is the owner, an HVAC contractor. It’s a concrete slab over steel floor and trusses.
When I moved in about 3 yrs ago, there was a crack running (IIRC) perpendicular to the floor joists, parallel to the girders but very thin. Not an open crack but a hairline. About a year ago, I noticed the crack had widened to maybe… 1/16 gap? I talked to them about it, we made the typical sky is falling jokes and as far as I know nothing further was done. Well, this morning I got a 7:30 AM phone call from the guys downstairs asking me to come to the shop. Apparently, yesterday one of them heard what he described as a faint crackling noise that he couldn’t localize. This morning though, he was in his shop and heard a loud “bang”, not like something dropping but more of a cracking sound. He measured the distance to where he was standing and when we transferred those measurements upstairs… guess where they fell. Now, I can’t see that the crack is any worse, and we can’t see the underside of the slab as it’s covered by decking. No signs of anything in the foundation or dw but needless to say it’s…unsettling, pardon the expression.
I’ve strongly suggested getting an engineer in to examine the place, maybe they will. I plan on calling the other brother, who’s more of the brains in their operation and seeing what he plans to do.
WWYD? Any ‘crete guys out there with an opinion?
TIA… wearing a hard hat in the shop for now.
PaulB
Replies
My wild arse thought lies on the integrity of the joists and beams. If they're OK, 'poxy the crack - properly.
http://en.wikipedia.org/wiki/Sampoong_Department_Store_collapse
Get out while you still can! ;-)
I think you are going to have to get rid of that swimming pool you got in your shop... ;-)
If you haven't read this story, posted by Biff Loman, I suggest that you do so. Several ominous similarities.
http://en.wikipedia.org/wiki/Sampoong_Department_Store_collapse
What similarities? In South Korea, they cut out several to many beams, and entirely changed the load path of the building. Then they added a floor, eight restaurants, and a ice skating rink and it's associated mechanicals.
Here is a small building, with some pops and cracks. And we have no idea what the problem is, but it is certainly nothing like what happened in South Korea. Furthermore, in South Korea the building sounds like it was a Post Tensioned concrete structure, while the building in question here appears to be a metal pan deck structure.
There may or may not be reason to be concerned, but bringing up very different accidents is unnecessary.
I deleted my earlier post because I'm in no position to judge a structure.
I don't know where the noise is coming from.the statement I made was, with concrete on decking being held by trusses and girders, the concrete is most times non structural, most time its only three inches thick with no rebar..two ways to screw up concrete 1) concrete driver 2) concrete finisher
brownie, Thank You! I was able to deduce and fully appreciate your reason for not making the post public. No problem , but it still left me wanting to hear your input because of you expertise. My desire for the information overcame my better judgment about pushing for it.
My apologies.
They can't get your Goat if you don't tell them where it is hidden.
the concrete is most times non structural
Yes, but sometimes the concrete is designed as part of the structure, and you have a composite deck. I think the metal deck is a little different than the normal profile."Put your creed in your deed." Emerson
"When asked if you can do something, tell'em "Why certainly I can", then get busy and find a way to do it." T. Roosevelt
I was kidding. :-)
Edited 2/2/2008 12:23 pm ET by Biff_Loman
What similarities?
The expanding crack and the loud bang are the similarities to which I referred. The recent loud band (or whatever noise it may have been) is the one which would have my immediate concern.
I'd be on a ladder with a big light, popping out ceiling tiles and having a good look as my first move. Could be a broken weld on a bar joist. That's the kind of thing which would make a loud bang. I once heard a weld break under a high load. Sounded like a medium bore rifle shot.
Whether I found anything or not I'd also be calling the building department and asking for an engineer to inspect as soon as they open on Monday.
If I had the BI's home or cell numbers I wouldn't wait until Monday. Might even call the fire department on their business line and speak with the captain about it. Let him decide whether to call for an engineer right away.
You got any better ideas? Let's hear 'em.
P.S.: My home is near a town where there was a two story commercial building collapse some years ago. Caused by snow and ice load on the roof. It was completely unexpected and took several lives.
Edited 2/2/2008 1:57 pm by Hudson Valley Carpenter
Thanks McMark, but I was taking all the real gloom and doom with a pinch of salt ;)PaulB
I don't know if this is entirely applicable but about 15 years ago I was looking after an appartment building and a similar thing happened. The building had 2" of concrete over decking and 2x10 joists with a steel beam supporting them over a large living/dining area. The steel beam was supported by wood posts and over the years something settled. There was a loud CRACK right along the point where the steel beam was and the tenents called me. The BI at the time decided that it was simply that - a bit of settling. (It seems that plain old concrete doesn't flex very well). There were no problems with the floor and no other incidents like this up to when I left that building 5 years ago.
Edited 2/2/2008 4:37 pm ET by mguizzo
Thanks BB, I was hoping you'd chime in. That does make me feel a bit better... I just hope I'm not in there the next time there's a loud bang. I don't carry extra u-trou ;)
PaulB
OK, I too would have been interested in BB's response. Now I guess I will just have to imagine what was posted.
They can't get your Goat if you don't tell them where it is hidden.
"t's a concrete slab over steel floor and trusses."
What KIND of trusses? Wood ones, or steel bar joists?
Sorry BH, I meant steel floor and (steel) trusses...PaulB
O.K. - Just curious.I heard about a guy not too far from here who used some floor trusses for a garage floor. Then he poured a concrete slab on top and parked his cars on it. Never did hear what happened to the structure....
He can compress the most words into the smallest idea of any man I ever met. [Abraham Lincoln]