# Fiberglass Insulation vs Spray Foam Insulation



## Yodaman (Mar 9, 2015)

Regarding health concerns of spray foam, get the MSDS sheet for the specific product(s) that you or the contractor would be using.


From my understanding offgasing diminishes rapidly as the product cures. After the foam is fully cured and the building is aired out there is little health risk.
Further reducing risk, there would likely be a layer of drywall between the foam and living spaces.


I would not equate spray foam at all to vaping where the individual inhales gases directly into the lungs.


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## SPS-1 (Oct 21, 2008)

Besides R value, the other nice thing about closed cell spray-foam is that it is airtight. Suppose it depends on your project, but I have a project going on right now where the air sealing of the spray foam is highly desirable.

If it cures properly, than I would accept that the health concerns are negligible. The risk is, if the installer screws up the mixing, and it does not fully cure. Spray foam is not a good candidate for simply going with the cheapest price.


.


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## joed (Mar 13, 2005)

Fumes would not be a concern to me except when installing.


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## Kemper100 (Sep 16, 2017)

Yodaman said:


> Regarding health concerns of spray foam, get the MSDS sheet for the specific product(s) that you or the contractor would be using.
> 
> 
> From my understanding offgasing diminishes rapidly as the product cures. After the foam is fully cured and the building is aired out there is little health risk.
> ...


I received a quote for spray foam in my crawl space (BASF Spraytite 158 Closed-Cell 3" R-19.80)

It also came with a disclaimer statement to sign.

Here's part of it:

Homeowner Requirements 
Your home must be uninhabited (including pets) during the application of spray foam and at a minimum 24 hours after the process is completed. This timeline may be extended based on environmental and ventilation conditions for up to 72 hours. Anyone with special health conditions like asthma should consult their physician on extended re-entry time. 

This made me a little concerned plus a few things I've read online about the product.


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## 3onthetree (Dec 7, 2018)

Kemper100 said:


> From what I've read spray foam insulation is substantially more efficient but more costly but I'm mostly have issues with the health concerns.


Yes yes and who knows. It sometimes takes decades to fully understand what a building product does to it's surroundings. Our houses and bodies are filled with plastics and chemicals. Draw your line where you feel comfortable, there are many ways to skin a cat.


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## Bud9051 (Nov 11, 2015)

Products have changed but verify the minimum temperature at which it can be installed.

Also discuss with your local authority as to any need to cover the foam with a thermal barrier or other. Don't let the installing company tell you not needed.

Natural air flow within a house is from bottom to top so any off gassing would typically travel through the house.

Does your crawlspace have a concrete floor or dirt? Are there any moisture issues down there?

How much head room down there?

If you have flat walls and standard rim cavities the alternative of using rigid foam panels or other rigid insulation along with a lot of caulking can be considered.

Bud


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## APA (Jul 13, 2018)

Get a quote for encpsulating your crawlspace with a heavy vapor barrier and foam board. I am leery of spray insulation. You are really manufacturing foamboard on-site. Too many variables to cause issues and it is basically permanent...


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## ktownskier (Aug 22, 2018)

Read the issues with fiberglass and other types of insulation as well. All types of insulations have their problems. Not just spray-foam insulation. 

And there are several types of spray-foam insulation. 

I had my addition spray-foamed and I would do it again in a heart beat. Not only because it made things a lot warmer. It made them so much quieter!!

The main thing, as with any building project, do your homework.


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## Nortron (Oct 17, 2019)

I'm no pro for sure, but my concern with Spray Foam is the fact it's literally stuck there forever... What happens in an older home if years later I need to do a repair, etc. I can't just pull out the insulation, it's literally painted on and would need to be scraped out...


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## Calson (Jan 23, 2019)

I looked into spray foam extensively last year and decided against it. If it is applied incorrectly with the wrong mix by the guy doing the spraying it can off gas indefinitely and the only fix is to mechanically tear it out. In some cases people have had to have their roof removed and then rebuilt as the foam was sprayed to the ceiling of the attic. 

The information from the foam manufacturers as to when you can re-enter the house is based on having the air in the space exchanged a minimum number of times during the spraying and for 24 hours afterwards. Not one of the 3 contractors in my area do any air extraction after they leave a house so the offgassing stays trapped in the attic and can take weeks to disappate (given that the attic is not a "conditioned" space and has vents to the outside air). 

I figured that I would need to spend at a minimum 4 days at a local hotel and added the cost for that and for meals to the cost of using the spray foam product. Realistically the 4 day period would not be long enough for the outgassing to have stopped. If there is more than 3 inches of foam applied the outgassing period can double. 

The federal government was going to ban the most dangerous types of spray foams containing the carcinogin dioxane and isocyanates in 2020 but with Trump in the White House this ban may not be in effect. Testing of houses 9 months after the foam was sprayed have shown very high levels of toxins present in the attic air. This includes the added surficants and flame retardants and by-products of the chemical reactions in the foam.

I decided to go instead with blown-in fiberglass insulation in my attic. When making a decision if the economic or health costs are too high then I do not roll the dice and hope for the best.

By the way, the cost for closed cell SPF was going to be more than $10,000 as compared to less than $4,000 for the blown in insulation and the payback with the reduction in heating costs with the spray foam would have taken me more than 20 years to recover.


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