DIY spray foam?

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  #1  
Old 12-24-19, 01:30 AM
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DIY spray foam?

I'm working on buying a second house for an investment property. A section under this house is open air and used as a carport. The floor above has 2x6 joists and absolutely no insulation, for about 300 sq ft. It appears to previously had fiberglass insulation but probably got dirty from being exposed to the elements for 30 years, and somebody ripped it out.

This area needs to be insulated. I'd rather use closed cell spray foam, about 2" thick. This will give me a nice vapor barrier and help glue the old subfloor together and keep the squeaks down. (relatively mild but humid North Carolina) Also a good fire barrier.

Question is how hard is it to use one of those do it yourself kits? The kind that look like 2 propane tanks. I can buy a 600bf kit for under $800, and that's about how much I would need for this project. The working height would be about 7', so it shouldn't be too complicated of an area. Besides suiting up in Tyvek and a respirator, is it really that difficult to do?

I feel like hiring a pro would be too expensive for such a small job. If it works out I can think of other places I would like to do this in the future...
 
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Old 12-24-19, 04:24 AM
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Froth Pak!

Not horrible to use, used once to patch foam removed from my spa leak repair.

As long as you were spraying in a direction that it had something to sit on, overhead applications would drip with too much material till it set up, the stuff is super sticky!

They come in a variety of sizes so you just need to calculate the volume needed!
 
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Old 12-24-19, 05:32 AM
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Because this is all overhead, I was thinking I would spray about 1" first and let it setup some, then come back and do another 1" and get any areas I might have missed. Will I have an issue getting 1" to stick overhead?

How much waste should I account for when estimating how much I need? If I get a 600bf kit that should cover 300sq ft at 2" thick, but what will it really cover in reality with a non expert spraying?

 
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Old 12-24-19, 06:18 AM
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In my case I found the limit was about 4", anything more and it would start to drip so 2" should be fine.

As far as waste, I don't have enough exposure to say!
 
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Old 12-24-19, 11:26 PM
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You said "Also a good fire barrier." Check your local authority but in many cases exposed spray foam must be covered with an ignition barrier. I don't believe it serves as a fire barrier.

Bud
 
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Old 12-25-19, 04:21 AM
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Depends on the material used, can have a class A rating.
 
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Old 12-25-19, 06:32 AM
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Marq, do you have a brand name in mind? Dow Thermax foam board is the only one I'm familiar with that can be left exposed but times change.

Bud
 
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Old 12-25-19, 08:37 AM
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National Fire Protection Association per NFPA 286 testing, can be left exposed in non-fire-resistant-rated roof/wall junctures, maximum 6 high and 2 deep (unlimited width)


https://www.dupont.com/products/frot...nsulation.html
 
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Old 12-25-19, 09:31 AM
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From your link:
Froth-Pak™ 210 Foam Insulation Kit.
"Complies with ASTM E84/UL 723. Underwriters Laboratories, Inc. (UL) Classified, see Classification Certificate R7813. National Fire Protection Association – per NFPA 286 testing, can be left exposed in non-fire-resistant-rated roof/wall junctures, maximum 6” high and 2” deep (unlimited width)"

And from that you feel the local authority will approve the op's application without talking to them and getting their approval?

Only way to be sure would be to talk to that local authority.

Bud
 
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Old 12-25-19, 06:28 PM
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Closed cell spray foam is almost universally class A fire rated these days. It would be harder to find some that wasn't than accidentally get some that is.

https://www.energyefficientsolutions...AaAmZBEALw_wcB

https://sprayfoamkit.com/shop/foam-i...caAl6fEALw_wcB

https://www.amazon.com/Froth-Pak-Cla...a-668123723894

https://www.acehardware.com/departme...B&gclsrc=aw.ds

As for asking the "local authority", that would be "Jimmy" in my county that has less population than most small towns. Not much Jimmy says is official, and Jimmy will say anything if you buy him a case of beer.

Chances are I will probably cover it with a thin sheet metal ceiling like you would find in a shop or something. Depends on how bad it looks when I'm done.
 
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Old 12-25-19, 06:44 PM
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LOL, local authority does vary with location. Maine had a big problem with some towns having no codes at all while others went by the book or better. They fixed it for the most part with state wide regulations, towns can adopt and modify if their requirements are stricter. Very small communities are still optional.

Only other body that can have a voice is the insurance industry. They pulled surprise inspections around here and i had a real battle with them.

Enjoy
Bud
 
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