The electrical room in the basement of the condo building I live (3 floors + basement, top floor has a mezzanine, 8 units total, in Montreal, Canada) has walls not finished. See photos.

There are gaps in the corners that weren't finished, so basically free air flows into the walls. I wonder if this has a function, or it was just laziness from the builder to save time.

Are these openings something that we can fill with silicone and be done with? Any recommendations on how to proceed?

More information:

My concern with these gaps is that due chimney effect the air flows to my unit (top floor). I have to keep on top of other units so they periodically fill the P traps that dry (especially the emergency one, next to the hot water tank, that one is never used). BTW: I do not discard that there is a crack in the vent system, but again, the smell goes up, from within the walls. I already got two different companies checking for mold, and a plumber who wants to do a smoke test, but the condo association just doesn't smell anything (according to them). So I am left with no options.

I'd like to minimize the flow of air.

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  • What are you asking exactly? – Greg Nickoloff Sep 17 '19 at 17:52
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    @GregNickoloff Whether the gaps can simply be filled with the first product that comes to mind, or whether particular products should be used, or whether they should not be filled at all. – Harper - Reinstate Monica Sep 17 '19 at 19:23
  • They could make you take it all out if you do not get approval. – Ed Beal Sep 17 '19 at 21:28
  • @harper - yeah I guess so. There was a bunch of other stuff about water heaters and smoke tests and so on.... – Greg Nickoloff Sep 18 '19 at 0:29
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    @rufo many years back I learned a trick that helps to seal unused floor drains without plugging them. A cup of cooking oil in the drain works wonders it doesn’t evaporate and as long as there is not a high flow situation it will last years. The oil traps the water on the house side and on the plumbing side the humidity is high so it doesn’t evaporate. I learned this when I had a basement that we had a dehumidifier in that caused the trap to need filling regularly. After adding the cooking oil I never had to add water again but I only lived there ~2 years after that. I would give oil a try. – Ed Beal Sep 19 '19 at 13:25

Yes, the gaps are a “Fire Code” issue, ( in the U.S., anyway...I don’t know about Canada, but I suspect it’s similar.)

You indicate your building is 3 stories plus a basement. In the U.S., this requires “Fire Resistant” construction, unless there are automatic fire sprinklers throughout the building.

What this means is that gypsum board must be on each side of each wall to protect the structural framework of the building. They call this a “1-hour Fire rating”. Without this gypsum board covering the building is “non-rated construction” and the building is limited to 2 stories.

Gaps in the gypsum board covering is of utmost concern in the electrical room where a fire is of extreme importance.

I would notify my HOA or building management services of this concern. If they do not take action, I’d notify your local Building Official of your concern.

I doubt the gaps are creating a smell into your unit. There may be a broken sewerline in the wall that allows a smell to seep into your unit. If you cal “rattle” pipes, that would be an indication that pipes are loose, broken, etc.

Another option to your smell situation could be that a vent below you is tied into your sewerline allowing the smell to seep into your unit through the plumbing vents. You’ll need access to the lower units and a smart plumber to figure that one out.

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