How to stop odor coming through common wall
shinterface
| Posted in General Questions on
Hello,
We have a commercial property (See A) built in the 1950s that is next door to a Cigar Shop (See B). Odor from the cigar shop is seeping into our property through the interior brick walls between the properties. The smell is intense and affecting business. I believe there is little to no installation between the two properties. Would sealing the wall with a polyethylene paint minimize the odor? What else can be done? Sorry, I’m very inexperience and if this the wrong forum, I apologize.
Cheers,
Danielle.
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Replies
You need to air seal the common wall. Most paints cannot either initially or over time maintain a seal at the hairline cracks formed at the interface of the mortar and brick.
If this wall either is or can be concealed, best thing would be a fluid-applied barrier, such as Sto Emerald Cote, such recommended here: https://www.jlconline.com/how-to/insulation/old-school-meets-high-tech-air-sealing-a-brick-row-house_o.
Peter
Thanks Peter. Where can I tell my contractor to buy Sto Emerald Cote?
Usually a layer of drywall does a good job of sealing up bricks. Old school plaster works even better.
If you want to have the exposed brick look, getting it tuckpointed and clear coat over the whole thing is about the only option.
Lot of times the problem isn't in the bricks but the floor joists. Older building will have the floor joists pocketed into the wall, sometimes the floor joists from one place stick all the way through to the other place. Even if the floor joist doesn't stick through, there are usually big cracks and gaps in this area. Usually the only way to seal that up is dropping part of the ceiling and spray foam over the area.
One option might be to try and pressurize the place slightly. It would cost extra energy as this air would have to be heated and cooled. Small positive pressure might be enough to keep the smoke at bay. You can try to see if that is enough with a box fan blowing in through an open window in the back.
Thanks Akos. The building has a 1st, 2nd, and 3rd floor, so I'm assuming I would have to remove the wood flooring near the wall and examine the floor joist.
Might be best to drill a couple of holes in a non conspicuous area in the ceiling and peek in before starting. Pulling up the floor works but generally more work than patching drywall. Unless you need to replace the flooring, the ceiling is easier.
Make sure you check on every floor, I have a place where there was no blocking to the neighbor on the 3rd floor (the floor joist bays were essentially connected between the two sides). The older the building, the worst these types of issues tend to be.
+1 for using pressure. It doesn't take much to stop all air flow.
First thing to do is to make sure there are no shared air ducts between the two spaces (buildings?). Damper off anything that is shared, but be sure you don’t inadvertently cause any problems for the system.
Next thing to check is to be sure you don’t have any openings in the wall between the two spaces. Check everything others have mentioned, but also check electrical services which are sometimes back-to-back in walls and open.
If all else fails, try pressurizing the space slightly with outdoor air, being careful to position the air intake so that it doesn’t suck in any of the offending odors. A small duct booster fan running “backwards” is probably sufficient. Remember that regular wall/roof vents have dampers that will block airflow going into the building, so you’ll need something without a damper.
Bill
Thanks Bill. Can you recommend a duct booster fan? Your post was very informative.
-Danielle
I can't really recommend any particular products. I would recommend contacting a mechanical contractor you trust and asking them to recommend a suitable fan and duct installation.
All you need to do is provide enough pressurized airflow going INto the building to cancel out whatever natural air intake there would otherwise be through cracks and leaks. You want to make sure the only air coming in comes through your fan, and that all the random leaks flow air OUT of your space. This way you're able to control what is coming in. Make sure there is an air filter on that inlet too, otherwise you're likely to suck in all kinds of random stuff (bugs, cottonwood fuzzies, etc.).
Bill