Building 'Bangs' in Cold Weather
Building 'Bangs' in Cold Weather
(OP)
Greetings -
Since a recent cold spell in our area (10-20°F daily average) we've been hearing occasional loud bangs in the office from above the ceiling. It's a one-story building with a high ceiling plenum. The ceiling is truss steel holding up corrugated metal. Sort of like your typical K-mart ceiling. The building's pretty wide & flat, like a large square. Maybe 30,000 square feet total.
I think the snow accumulation up there's pretty minor.
Some of these bangs are significant - like taking a baseball bat to a dumpster kind of sound. Other times it's minor metallic popping sounds. No steam or water in the ceiling so it's not hammer. I'm pretty sure it's not coming from the HVAC system. Someone suggested building contraction... any thoughts on this? Thanks. -CB
Since a recent cold spell in our area (10-20°F daily average) we've been hearing occasional loud bangs in the office from above the ceiling. It's a one-story building with a high ceiling plenum. The ceiling is truss steel holding up corrugated metal. Sort of like your typical K-mart ceiling. The building's pretty wide & flat, like a large square. Maybe 30,000 square feet total.
I think the snow accumulation up there's pretty minor.
Some of these bangs are significant - like taking a baseball bat to a dumpster kind of sound. Other times it's minor metallic popping sounds. No steam or water in the ceiling so it's not hammer. I'm pretty sure it's not coming from the HVAC system. Someone suggested building contraction... any thoughts on this? Thanks. -CB
RE: Building 'Bangs' in Cold Weather
Cheers
Greg Locock
RE: Building 'Bangs' in Cold Weather
RE: Building 'Bangs' in Cold Weather
RE: Building 'Bangs' in Cold Weather
I'll go up there tomorrow and re-post what I see.
Watermelon, I'm not sure. I only see joints in sheetrock in long corridors. Roof is membraned over, exterior is stucco'd. If I had to bet, probably not sufficiently, if at all!
Thanks for your inputs! -CB
RE: Building 'Bangs' in Cold Weather
TTFN
RE: Building 'Bangs' in Cold Weather
Good idea to check the roof load and not make any assumption. The old adage comes to my mind: when I ASS-U-ME, I make an ASS out of U and ME.
My understanding of expansion/contraction joints is they should be added when buildings approach 120 feet. I will probably be shot down on this site for saying that, but oh well. Your building measures approx 175 x 175, so one might expect to see a joint.
Next, they are easy to I.D. You should see joints in the exterior, in the floors and maybe columns very close together at the joint. If you had them, you'd know.
It sounds to me like there is some kind of movement taking place as a result of temperature changes. Maybe some joists that are not welded down.
My only concern is this: (and I don't want to ring any alarm bells) When a weld snaps suddenly, it makes a sound like a gun being fired.
Best you grab a flashlight, remove some ceiling tiles and have a look-see. Due diligence. Get the snow off the roof first. And don't stockpile it on the roof.
RE: Building 'Bangs' in Cold Weather
RE: Building 'Bangs' in Cold Weather
I have not experienced such "bangs" since.
With regard to bolt slipping, I have witnessed several full scale transmission tower tests. These towers are loaded until they collapse. Loud noises are normal and they come from bolts slipping into bearing. However, they are different from the "roof bangs" Also, we start hearing "bolt bangs" when loading is beyond 75%. I don't think buildings are ever loaded beyond 75% of their structural capacity.
No doubt, an interesting topic.
RE: Building 'Bangs' in Cold Weather