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Ask me anything about spray foam insulation

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  • Oct 2nd, 2019 4:19 pm
Newbie
Oct 25, 2012
58 posts
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Toronto
more of a comment than question.....
i live in an 85 year old house with radiator heating, no forced air or A/C (other than a couple of wall mounted units). I finished my basement in the summer, using spray foam and found that I now have an extremely humid basement, with very stagnant air in the basement. Promblem is that everything is so air tight, i get no air circulation (remember, i have no forced air)...... nobody warned me about this and now i am concerned about mould and quality of air down there!!!
Deal Addict
Nov 18, 2005
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Kitchener
jman1717 wrote:
Feb 18th, 2014 4:55 pm
more of a comment than question.....
i live in an 85 year old house with radiator heating, no forced air or A/C (other than a couple of wall mounted units). I finished my basement in the summer, using spray foam and found that I now have an extremely humid basement, with very stagnant air in the basement. Promblem is that everything is so air tight, i get no air circulation (remember, i have no forced air)...... nobody warned me about this and now i am concerned about mould and quality of air down there!!!
You should be concerned about it, I would recommend a hrv or a dehumidifier
[OP]
Jr. Member
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Feb 3, 2014
146 posts
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Mississauga
G55man wrote:
Feb 17th, 2014 10:45 pm
I'm considering spray foaming my basement walls and rim joist. I had one contractor tell me I will get a lot more spiders with spray foam as opposed to other methods, is there any truth to this? I don't see how one method over another would change the amount of spiders in a house.

Thanks
Sounds like BS. Spray foam would seal all the cracks in your foundation wall, in fact preventing insects from getting in from the outside.
Becks wrote:
Feb 18th, 2014 4:39 pm
Has the OP ever spray-foamed over a greasy attic or smokey (smoke from a fire) attic?
Spray foam cannot be applied over a greasy substrate. It must be clean, dry, and free of debris to have proper adhesion. Anything with smoke damage should be painted first with a special paint to cover up the grease/smoke damage.
Drthorne wrote:
Feb 18th, 2014 8:13 pm
You should be concerned about it, I would recommend a hrv or a dehumidifier
Also, something as simple as opening the window(s) in the space from time to time will help a lot.

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Peter
Owner, VIPFoam.com
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Peter
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Drthorne wrote:
Feb 18th, 2014 8:13 pm
You should be concerned about it, I would recommend a hrv or a dehumidifier
I'm no expert but humidity that high means lots of water is getting in from somewhere, if you have adequate ventilation your humidity should be below 30% right now (unless your adding it in via humidifier or furnace humidifier)
I would take the HRV over the dehumidifier, i assume it will use less energy and fresh air is much healthier then stale air with water sucked out of it. Fresh air in winter will have low humidity, and transient high humidity fresh air days in spring and fall won't damage much, and central air will handle summer humidity (if you have it). Also the HRV will improve indoor air quality, but it does come with cost (probably less lifetime cost hten a dehumidifier but i am not sure because i have not specifically run the numbers)
Member
Jan 14, 2005
342 posts
4 upvotes
How much spray foam should I have from the builder within the drywal above my garage? The rooms above are cold and i'm not sure If I need more.
[OP]
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Feb 3, 2014
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Mississauga
sketty55 wrote:
Feb 20th, 2014 1:35 pm
How much spray foam should I have from the builder within the drywal above my garage? The rooms above are cold and i'm not sure If I need more.
Most builders use half pound foam for ‘bonus room applications’ like garage ceilings or porch overhangs (it's cheap and the average consumer doesn’t know the difference between 0.5 and 2lb). No amount of fibreglass / half pound foam will suffice. As for quality 2lb foam, you’d need about 4.5 to 5 inches depending on the brand or colour. 1st check if you have half pound or 2 pound. Easiest way to check is to poke it with your finger; if your finger goes through it, it’s likely 0.5 pound, if not it’s 2 pound. If you do have 0.5lb there is a way to address the situation without removing a lot of it. What you want to do is remove the foam 4 inches back from the perimeter of the exterior facing walls. Have that filled all the way to the sub floor then spray over the existing foam with 2lb foam, about 4 inches thick over the whole area. It’s not the most ideal way of doing it but it will save you over 100 garbage bags of ripped out foam.

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Peter
Owner, VIPFoam.com
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Peter
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Deal Addict
Mar 11, 2007
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QC
jman1717 wrote:
Feb 18th, 2014 4:55 pm
more of a comment than question.....
i live in an 85 year old house with radiator heating, no forced air or A/C (other than a couple of wall mounted units). I finished my basement in the summer, using spray foam and found that I now have an extremely humid basement, with very stagnant air in the basement. Promblem is that everything is so air tight, i get no air circulation (remember, i have no forced air)...... nobody warned me about this and now i am concerned about mould and quality of air down there!!!
Your contractor should have told you... He was maybe scaried to told you that, fearing you would not take the contract because installing an HRV in an old house is not cheap.

Its not breathing like it was before. An HRV is defenitly a must. My house has 50 years and did the spray foam/hrv combo last summer/autumn and the basement is much more confortable and do not smell humidity like it was before.

Installation cost for a Lifebreath was 3500$ for my bungalow. I have like you radiator heating. Basement has no heating yet but still a confortable steady 20C.
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PeterLN wrote:
Feb 20th, 2014 10:20 pm
Most builders use half pound foam for ‘bonus room applications’ like garage ceilings or porch overhangs (it's cheap and the average consumer doesn’t know the difference between 1.5 and 2lb). No amount of fibreglass / half pound foam will suffice. As for quality 2lb foam, you’d need about 4.5 to 5 inches depending on the brand or colour. 1st check if you have half pound or 2 pound. Easiest way to check is to poke it with your finger; if your finger goes through it, it’s likely 1.5 pound, if not it’s 2 pound. If you do have 1.5lb there is a way to address the situation without removing a lot of it. What you want to do is remove the foam 4 inches back from the perimeter of the exterior facing walls. Have that filled all the way to the sub floor then spray over the existing foam with 2lb foam, about 4 inches thick over the whole area. It’s not the most ideal way of doing it but it will save you over 100 garbage bags of ripped out foam.
The air cavity installation i mentioned had the foam you could push your finger through, its surprising that 0.5lb could make such a difference.
How much R value would he be losing by having that over the 2lb?
Newbie
Feb 10, 2014
35 posts
How does it compare to traditional insulation in terms of health risks? (not when installing, but after the fact).

I would assume it is much better
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Mar 11, 2007
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DirectAirFilter wrote:
Feb 22nd, 2014 10:30 am
How does it compare to traditional insulation in terms of health risks? (not when installing, but after the fact).

I would assume it is much better
You have to cover it with drywall. It shouldnt really degrate over time.
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Feb 3, 2014
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Mississauga
Quentin5 wrote:
Feb 20th, 2014 10:54 pm
The air cavity installation i mentioned had the foam you could push your finger through, its surprising that 0.5lb could make such a difference.
How much R value would he be losing by having that over the 2lb?
On average, 0.5lb foam has an R-Value of 3.5/inch while 2lb foam has an R-Value of 5-7/inch depending on the brand.
DirectAirFilter wrote:
Feb 22nd, 2014 10:30 am
How does it compare to traditional insulation in terms of health risks? (not when installing, but after the fact).

I would assume it is much better
Good quality foam doesn’t have any VOCs . After the installation the foam is fully inert and doesn’t do any off-gassing so it’s completely safe. Also, it doesn’t promote any mold or fungi growth which can happen with traditional insulation and does not allow for mice, insects, etc to make make nests in it.

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Peter
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Peter
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Oct 25, 2003
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Hi Peter,

I have a 25 year old house that we just moved into in the summer and this winter we have noticed significant drafts coming from all parts of the house and a huge utility bill as a result.

Because the house has already been refinished to a high standard, we have no intention of taking down drywall to insulate unless it is the only option.

My question is, how do you spray foam a house if the home owner doesn't want you to touch the interior? Can it be done effectively and is it really expensive due to increased labour? I'm really looking for a step by step of how you would accomplish this.

Is it better to use spray foam or would it be more effective to take down the siding and put up Styrofoam sheets before putting the siding back on?
[OP]
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Feb 3, 2014
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Mississauga
llcooljayce wrote:
Feb 22nd, 2014 12:13 pm
Hi Peter,

I have a 25 year old house that we just moved into in the summer and this winter we have noticed significant drafts coming from all parts of the house and a huge utility bill as a result.

Because the house has already been refinished to a high standard, we have no intention of taking down drywall to insulate unless it is the only option.

My question is, how do you spray foam a house if the home owner doesn't want you to touch the interior? Can it be done effectively and is it really expensive due to increased labour? I'm really looking for a step by step of how you would accomplish this.

Is it better to use spray foam or would it be more effective to take down the siding and put up Styrofoam sheets before putting the siding back on?

If you want spray foam and don’t want to touch the interior, the only option is to do it from the outside. It can be done effectively, but requires a few extra steps like renting scaffolding and tarping the house to prevent overspray. Obviously, these extra things cost a bit more.

In terms of the better insulator, you’re better off going with the exterior foam than Styrofoam. It will perform better because it’s adhered to the wall as opposed to being screwed on. I’m afraid I can’t say which option would be cheaper, because I don’t know my way around Styrofoam pricing.

--
Peter
Owner, VIPFoam.com
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Oct 25, 2003
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PeterLN wrote:
Feb 22nd, 2014 2:13 pm
If you want spray foam and don’t want to touch the interior, the only option is to do it from the outside. It can be done effectively, but requires a few extra steps like renting scaffolding and tarping the house to prevent overspray. Obviously, these extra things cost a bit more.

In terms of the better insulator, you’re better off going with the exterior foam than Styrofoam. It will perform better because it’s adhered to the wall as opposed to being screwed on. I’m afraid I can’t say which option would be cheaper, because I don’t know my way around Styrofoam pricing.

--
Peter
Owner, VIPFoam.com
Could you give a real rough idea on how much it would cost to do a 2000 sq ft house with scaffolding, tarping, materials, labour, etc?
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Jul 27, 2006
906 posts
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Moncton
DirectAirFilter wrote:
Feb 22nd, 2014 10:30 am
How does it compare to traditional insulation in terms of health risks? (not when installing, but after the fact).

I would assume it is much better
It sounds like it is pretty safe - but they said the same thing about urea formaldehyde back in the 70's. I'd hate to think they will find out in 20 years that this stuff is a health hazard as well and has to be removed at a huge expense. I know - it's very unlikely, but you never know.

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