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Ask me anything about spray foam insulation

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  • Feb 20th, 2019 11:04 pm
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phantomvs wrote:
Feb 13th, 2019 3:18 pm
Not sure if this has been asked.
I have a type of mansard roof/ siding on my 1974 home. This is for the siding only, roof is flat, with no attic.
I plan on changing shingles on side of home, now if i remove shingles and plywood can i use spray foam there on exterior wall to boost up r-value ?
Then reinstall plywood and shingles. Or is it better to insulate from the inside, just way easier on outside when renovating the roof.
Keeping inside intact not disturbing drywall.
Or will it cause moisture issues ?
Thanks !
Installing the foam from the outside is better because in your case you have a finished room inside and i assume you do not want to gut/renovate the house. That being said, when it comes to installing the foam and coordinating with the roofer and the weather (rain, temperature and wind), this option becomes a bigger headache and costs more money to do. This application should not cause moisture issues when done correctly. Once a house does become very tight (air sealed) it's recommend to have an HRV installed to your HVAC system or do periodical air exchanges by opening up a window from time to time.
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PeterLN wrote:
Feb 14th, 2019 12:31 pm
You can definitely have someone come out and spray your ceilings. As long as the back of your drywall is dry. Ensure boxes are installed over the pot lights too. The challenge with a job like this is coordinating your trades and the weather. Wind will be a big factor, even a small breeze can send over spray a few hundred feet away onto your neighbour's property or cars.

A full fill of the joists would be very expensive, all I would recommend is 5" is you are in the greater Toronto climate. 5" would be R31 in multiple layers. Any more then it would require an additional day for the install. As for your question about the gap, well that's more of a roofing question. We spray sloped ceilings often, some vented and some not. I read a study out of BC where they tested the temperature difference between the two and found it was minimal.
So would the other option be finishing the roof and then cutting 4-6” circular holes in the sheathing to fill the space?
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so were about to do the basement, should we be doing spray foam? cheers
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Gotoff wrote:
Feb 19th, 2019 12:59 pm
so were about to do the basement, should we be doing spray foam? cheers
Spray foam costs a lot more but provides better insulation. But if later on you decide to make changes, pass wires or need to reach the concrete wall then it is more messy than if you had, for example, batt insulation. There are pros and cons to anything you decide.
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TomLafinsky wrote:
Feb 19th, 2019 1:46 pm
Spray foam costs a lot more but provides better insulation. But if later on you decide to make changes, pass wires or need to reach the concrete wall then it is more messy than if you had, for example, batt insulation. There are pros and cons to anything you decide.
Does spray foam provide better sound dampening in terms of upstairs noise somehow?
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Gotoff wrote:
Feb 19th, 2019 1:53 pm
Does spray foam provide better sound dampening in terms of upstairs noise somehow?
If you mean to spray foam the ceiling of the basement then I would suggest you buy Roxul and install it yourself. You'll be saving A LOT of money compared to spray foam the ceiling. Before finishing my 2,000 sqft basement I installed Roxul in the ceiling of the basement and it does a wonderful job at elminating noise/sound.

Please let me know if this is not what you meant.
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TomLafinsky wrote:
Feb 19th, 2019 2:01 pm
If you mean to spray foam the ceiling of the basement then I would suggest you buy Roxul and install it yourself. You'll be saving A LOT of money compared to spray foam the ceiling. Before finishing my 2,000 sqft basement I installed Roxul in the ceiling of the basement and it does a wonderful job at elminating noise/sound.

Please let me know if this is not what you meant.

You got it right. Roxul is what I meant. How much did it cost you to diy your ceiling with roxul?
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Gotoff wrote:
Feb 19th, 2019 2:08 pm
You got it right. Roxul is what I meant. How much did it cost you to diy your ceiling with roxul?
A few days ago I checked HD's website and Roxul was $57 for 59 sqft. Measure the area and divide by 59 sqft and this will tell you how many bags you need. Add 13% tax and voila!

The Roxul bags are really big and even if you have a SUV you might have to do many, many trips. Or have HD deliver it to you.

Btw, installing Roxul is a piece of cake. Make sure to wear a breathing mask over the mouth (most important) and also protective glasses. Could also wear gloves.

Roxul is not just for soundproofing. It also provides fire resistance.
Last edited by TomLafinsky on Feb 19th, 2019 2:31 pm, edited 1 time in total.
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TomLafinsky wrote:
Feb 19th, 2019 2:23 pm
A few days ago I checked HD's website and Roxul was $57 for 59 sqft. Measure the area and divide by 59 sqft and this will tell you how many bags you need. Add 13% tax and voila!

Btw the Roxul bags are really big and even if you have a SUV you might have to do many, many trips. Or have HD deliver it to you.

Btw, installing Roxul is a piece of cake. Make sure to wear a breathing mask over the mouth (most important) and also protective glasses. Could also wear gloves.

Roxul is not just for sound dampening. It also provides fire resistance.

Installing it might be a piece of cake but don't I have to worry about all the electrical work I need to do first. Or rather my basement contractor.

I.e. potlights, wiring for kitchen / bath etc
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Gotoff wrote:
Feb 19th, 2019 2:30 pm
Installing it might be a piece of cake but don't I have to worry about all the electrical work I need to do first. Or rather my basement contractor.

I.e. potlights, wiring for kitchen / bath etc
Of course let the contractor do all its work before installing Roxul. Otherwise it will take him longer as the Roxul will be in the way and it might end up costing you more in labor. Even if he charges you a flat price instead of by the hour wait until all the work has been done before installing Roxul.
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Spray foam is good however you can look at it this way (at least in the basement since its not AS cold as upper levels) With the money you save from not spray foaming in the basement you could likely use 2 layers of Roxul in your ceiling to make it even better at sound proofing. Keep in mind Roxul will help with sound but usually its just the higher pitched sounds, like people talking, or a tv etc. It only helps a little with deeper sounds like feet stomping or the Bass from a subwoofer etc. So adding a second layer would help with sound even more.
Gotoff wrote:
Feb 19th, 2019 1:53 pm
Does spray foam provide better sound dampening in terms of upstairs noise somehow?
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sickcars wrote:
Feb 19th, 2019 5:28 pm
Spray foam is good however you can look at it this way (at least in the basement since its not AS cold as upper levels) With the money you save from not spray foaming in the basement you could likely use 2 layers of Roxul in your ceiling to make it even better at sound proofing. Keep in mind Roxul will help with sound but usually its just the higher pitched sounds, like people talking, or a tv etc. It only helps a little with deeper sounds like feet stomping or the Bass from a subwoofer etc. So adding a second layer would help with sound even more.
i saw in a youtube video a guy recommending 2x 5/8 drywall and green glue instead. Not sure if this is a practical approach since we want as much ceiling height as possible.

But the problem with roxul is that there's ductwork that cover some joist widths so itll be less effective.
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Well I'm not saying its the best solution but its an option since you would save money from not using spray foam.

Ideally if you had the money I would do 2 layers of Roxul then install a Resilient channel & put sound proof drywall on that. That would be ideal however more expensive.
Gotoff wrote:
Feb 19th, 2019 7:15 pm
i saw in a youtube video a guy recommending 2x 5/8 drywall and green glue instead. Not sure if this is a practical approach since we want as much ceiling height as possible.

But the problem with roxul is that there's ductwork that cover some joist widths so itll be less effective.
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ameds613 wrote:
Feb 15th, 2019 3:38 pm
Hi Peter, I found this gem of a thread and thank you for donating your time and expertise. I live in Ottawa but will recommend you to friends in the GTA.

I'm shopping for quotes to sprayfoam my basement headers. My number one concern is health of my family so I've opted for the Walltite Eco product and mandatory stringent application standards. I've noticed that you said in a past post to make sure its the Eco V3 and not the V2. I received a quote with the V2. What's the difference between the two? I've read both techinical data sheets but I dont know how to interprete the info.

Cheers!
Alex
V3 has the higher R value then V2. Just check the actual drums inside the spray rig to see what is the actual version you are getting.
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