Who is the best tradesperson to seal open gaps between two homes?

Question Icon
Posted by: from Toronto
10/4/2014 at 3:45:23 PM

Who is the best tradesperson to seal open gaps (small holes or crevices or unsealed floor joists) between two homes to stop and prevent air/*cigarette smoke moving from one basement to another basement in semi-detached house? Carpenter?

In my home, we use the basement as living and sleeping space. The neighbouring home has recently had a basement tenant move in - this tenant is a heavy smoker. For the first time in ten years, we can occasionally smell some cigarette smoke in our basement. The tenant often smokes outside, but with Winter approaching, indoor smoking is likely to increase.

It is not clear where/how*exactly* the smoke is coming from into our basement (other than knowing it MUST be from next door as we are non-smokers). At home while resting, working, socializing or sleeping, we don't want to smell cigarette smoke, have the odour on our clothing, furniture, hair etc., nor most importantly assume the health risks of breathing secondhand smoke.

I understand that it can be tricky to completely seal off or block up a shared wall. However, it is possible. I realize there's no legal REQUIREMENT to share air with one's semi-detached neighbours, and since it IS possible, with fastidious & attentive-to-detail effort, to cover every square centimetre of wall between two houses with either concrete cement, caulking, foam, steel or other non-porous material, who can I seek out to do this renovation/repair? It is my understanding that smoke will not get beyond a concrete fire barrier.

I am willing and must ensure that I do everything to protect my family's health. One of my children has a chronic health issue that it is unconscionable to add to with this discretionary exposure to secondhand smoke.

I welcome any feedback, ideas and recommendations.


User Icon
Date/Time10/4/2014 at 6:06:35 PM

You have to spray foam whole top plates and joists on the wall attached to other house then vapor barrier the drywall or build new wall on old wall with spray foam in between!


User Icon
Mike from Custom Designs in Bolton
Date/Time10/4/2014 at 8:43:18 PM


I agree with Mitchell, a new wall, spray foam, vapor barior should fix your issue. At the same time that wall is supposed to be fire rated. This means that there shouldn't be any smoke or fire able to travel through the wall.

A good place to start would probably be to call your local city building department and book an appointment with an inspector or engineer. If your house isn't that old your builder may be responsible to make repairs if it is. Your neighbour may be obligated to share the cost with you.

Good luck.


User Icon
Date/Time10/4/2014 at 11:59:43 PM

As posted by the others, spray foam is the answer to solve this problem. Using a smoke stick/pencil will show the movement of air between the two homes. This will ensure the spray foam is applied to the correct area to solve your issue.

Search the TrustedPros directory and discover the best contractors in your area.

Find your home service pro
Great renovations start with a great contractor.

Since 2004, TrustedPros has been helping homeowners find the right contractor for their home improvements and repairs.

Post Your Project

Within hours you'll be comparing offers from top-rated professionals. It's free to post and you're under no obligation to hire.

Trustedpros Inc. does not warrant the accuracy, completeness, safety, legality or usefulness of any Content, or Whether Content is Current and up-to-date, and TrustedPros Inc. Shall have no liability whatsoever with respect to your use or reliance upon any content or for content being removed or otherwise ceasing to be available. Please refer to the terms and conditions of use of this websites for more details.

Get Free Estimates

Post your project and compare offers from top-rated pros.