# New Construction Spray Foam Insulation



## Velosprints (Feb 11, 2019)

I am acting as GC for my new construction home build and I was wondering if anyone here has had experience with spray foam insulation for an entire house? I really think it will make a difference over time, but I am having trouble coping with the costs vs benefits.

Has anyone sprayed their own home, or had it done by a professional? In your opinion, was it worth it? Is it noticeable? Its sooooo expensive!!

Oh - and an important bit of info: I plan on spraying the insulation by myself. I can't justify hiring a contractor, so if it is to be, it is up to me.


----------



## joecaption (Nov 30, 2011)

Is it better, yes.
Is it a DIY job NO WAY!


----------



## Velosprints (Feb 11, 2019)

Why?


Sent from my iPhone using Tapatalk


----------



## Bud9051 (Nov 11, 2015)

We need to know your climate region, add a nearby big city to your profile.

I haven't done it because it cost too much, sound familiar.

I'm in the energy business and my take on spray foam insulation is the mfg's take so much profit it is barely cost effective use in a residential home. Plus, spray foam was more popular when homes were not well sealed. Today one can built a very tight home so the air sealing properties of foam add little to the benefit list.

Air quality inside a home requires a lot of fresh air. Once sealed super tight, which foam will do, you MUST add ventilation, search HRV (heat recovery ventilators).

IMO, DIY an entire house would be out of the question, bigger topic. Plus, using conventional well tested methods you can build a very efficient home all well within the DIY approach. Search "net zero" or "energy efficient" homes.

Bud


----------



## Velosprints (Feb 11, 2019)

I appreciate the response Bud. I live in northern VA in between Winchester and Leesburg. Does spray insulation help at all with sound dampening? The area I’m moving to gets extremely windy, and I’d love to dampen some of the noise. 


Sent from my iPhone using Tapatalk


----------



## Yodaman (Mar 9, 2015)

I feel your pain brother. When I did the complete remodel of my existing home I went out for spray foam quotes. The quotes came back at 4 to 5 times the cost of what I could do in fiberglass. So you can guess which route I took.
But there are some advantages to the foam which fiberglass is lacking. Air sealing is huge in todays super tight homes. High density foam excels here. Areas like around the the rim joist are difficult to seal and foam is great here. Other areas where achieving the desired R value in fiberglass might be difficult, high density foam is about as good as gets. Cathedral ceilings come to mind. 

You might ask you contractor to supply some ROI numbers to help wrap your head around the extra cost.


If you decide you need or want the foam, hire it out. Nearly everything I have read about DYI spray foam is negative. Cost savings is minimal as actual yields are lower than stated.
(this is bulk coverage spraying, not spot spray which I went through 2-3 cases? of great stuff)


----------



## Velosprints (Feb 11, 2019)

This is all good info. Thank you! To be honest, it’s my wife who is pushing the DIY foam job. I feel like we’d be in over our head QUICK


Sent from my iPhone using Tapatalk


----------



## SPS-1 (Oct 21, 2008)

joecaption said:


> Is it a DIY job NO WAY!





Velosprints said:


> Why?


 
Because if you screw up the mixing, it won't fully cure, and will off-gas toxic compounds for a very long time. (i.e bring out the bulldozer)


Also, the chemical reaction as it cures creates heat. Because it is such a good insulator, the heat has trouble getting out. If you spray it too thick, it can catch fire.


----------



## Bud9051 (Nov 11, 2015)

Even doing your own work or being your own GC has a lot of kinks that need to be considered and there are several threads here along those lines. In some locations a home owner can do almost everything, but in other places licensed contractors are required.

Do you have a piece of land already?

Bud


----------



## Velosprints (Feb 11, 2019)

Sure do. Second floor walls going up tomorrow. 


Sent from my iPhone using Tapatalk


----------



## joecaption (Nov 30, 2011)

Building it with 2 X 6 walls?
I live right on the bay in VA and wind noise has never been an issue.


----------



## Velosprints (Feb 11, 2019)

Unfortunately no. 2x4. 


Sent from my iPhone using Tapatalk


----------



## Richard Pryor (Jun 25, 2016)

With 2x4 you won’t be able to do more than r-13 I believe. Why not 2x6?

What about roof? You doing trusses? Rafters? 2x12 rafters? Vaulted ceiling?

I’m building a house now and also acting as a GC. I’ve been doing a lot of reading because I want my house to be perfect.

We did spray foam in a metal shop that we currently live in and it is very good but I get condensation where the chimney pipe exits the building. Other than that I like spray foam.

But I’m not doing it on my home. First because of cost and second because I believe you can do a good job if you do everything by the book with fiberglass.

Can you even do 2x4 in VA? New construction? R-13 is pretty weak.


----------



## Richard Pryor (Jun 25, 2016)

Oh, and forget about spray foaming your own house. It’s definitely not a diy job. Fiberglass is and you can save a lot of money that way.


----------



## Yodaman (Mar 9, 2015)

Velosprints said:


> Unfortunately no. 2x4.
> 
> 
> Sent from my iPhone using Tapatalk



2 x 4 walls and R13 fiberglass is light for the climate zone 4 recommendations. Are you planning to use Foam sheathing on the outside?


http://insulationinstitute.org/wp-content/uploads/2015/12/VA-2012.pdf


----------



## Windows on Wash (Aug 30, 2011)

There are other than "spray foam" ways of insulating the structure that will actually make it dramatically outperform a typically SPF cavity fill insulation application.


----------



## F250 (Feb 13, 2018)

I can't even begin to imagine choosing 2x4 wall construction anywhere I would want to live, and I'd even be willing to consider 2x8's if I were building from scratch.


----------



## ktownskier (Aug 22, 2018)

I built an addition and used spray foam. I was glad I did. There was a distinct difference the master bedroom (which was part of the remodel/addition) and the other bedrooms in both heating and cooling as well as noise suppression. 

So, would I do it again, if I had the money for it, yes. At the very least, I would consider a flash coat to seal any intrusions and then use either rockwool or just regular fiberglass. I like rockwool as it is a good sound deadener, and is mold and rot resistant.


----------



## Ca443 (Feb 11, 2019)

I have used spray foam for one area before. The kits they sell are pretty easy and I don't think it was as tough as others are saying. However, I would rather flash spray everything to seal and then use fiberglass. There is always that one extra outlet you want or a flat panel TV etc. 

My parents had a custom piece of furniture built out of oak by the Amish. It was an entertainment center that they believed would be a family heirloom. However, the spot for the TV was 4:3 and 10 years later the world move to 16:9. Basically what I am saying is...spray foam has it's benefits, but in the future will limit you if you ever decide you need to run a wire...however, the world is moving wireless.

As a vapor barrier it is great, as insulation it is great...However, if you really want sound reduction, there are drywall offset products, like resilient channel, or you could use insulation then two layers of 5/8 inch drywall with green glue.


----------



## APA (Jul 13, 2018)

Some of you guys must have unlimited funds to build houses. 2 X 8 exterior walls? 1 1/4" of sheetrock? Jeez...


----------



## listo (Nov 19, 2008)

When going through firefighter courses it was brought up that spray foam in a new build is a bad idea. As the studs dry they shrink slightly. The spray foam remains rigid and leaves small gaps between the insulation and studs. This causes a chimney effect that helps fires spread faster. Even though the void is very small I imagine that your insulation/vapour barrier would be compromised as well.


----------



## NotYerUncleBob2 (Dec 29, 2017)

You can get good R value with a 2x4 wall if you put up exterior rigid foam. Not sure what the sound dampening benefits of that would be, but it's a good insulation strategy. 
For good insulation and sound dampening in the 2x4 cavity, I'd suggest rockwool. Way cheaper than foam and it's fireproof. 
I love the idea of closed cell foam, but the cost is just too hard to justify if you've already done a decent job of air sealing during framing. As far as DIY for the foam, count up how many of those kits you'd need and I don't think it will be any cheaper than hiring a professional outfit to do it.


----------



## davison0976 (Jan 5, 2019)

Cost is one thing, but it's so ironic that today I had a conversation with someone at work who has spray foam insulation between his roof rafters. Problem is, his 30 year guarantee roof stated leaking after only 10 years now, but spray foam didn't make it evident for at least several years judging by the amount of rotten roof sheathing that now has to be replaced.


It turns out to be a major job now to repair everything, break away existing spray foam and insulate again. I am not sure if he is going with a spray foam this time around.


----------



## davison0976 (Jan 5, 2019)

NotYerUncleBob2 said:


> For good insulation and sound dampening in the 2x4 cavity, I'd suggest rockwool. Way cheaper than foam and it's fireproof.



Rockwool is a fantastic product. For interior insulation however, like wall cavity insulation, I would suggest a "AFB evo" version of the product because it's manufactured using a formaldehyde free binder. Other versions contain formaldehyde which is a known carcinogen. For exterior insulation, like comfortboard, formaldehyde based binder is fine.


----------



## schreibdave (Jun 12, 2016)

In terms of DIY spray foam, my neighbors had it PROFESSIONALLY applied in a renovation/repair area. The guy got the chemical mix wrong and my understanding is that the stuff off gases but wont cure. They vacated the house for several months, had an HRV installed and are now trying to sell. I think they may have had it all ripped out. They never moved back in. 

Not a DIY job.

Had it in my last house and loved it. House was comfortable and quiet. On my current home we went with extra attention to air sealing and fiberglass. It's not as good but good enough. If I had more money to spend I probably would have spent it on higher quality windows before I spent it on spray foam. Good luck.


----------



## Yodaman (Mar 9, 2015)

schreibdave said:


> If I had more money to spend I probably would have spent it on higher quality windows before I spent it on spray foam. Good luck.



This is a good point. I have read that 85% a homes heat loss is through doors and windows. While our walls and ceilings are R20 and R40, a typical double pane window is around R3, Even triple pane glass is only about R5.


----------



## Velosprints (Feb 11, 2019)

Ok, so if money was no factor, should I go with open cell or close cell in my 2x4 walls? Why?

Update: we are no longer going to DIY this project, thanks largely in part to the input from you fine folks. 


Sent from my iPhone using Tapatalk


----------



## schreibdave (Jun 12, 2016)

When we built our last house 11 years ago all of the walls were spray foamed with open cell.

It looks like the current advice for a cold climate is closed cell because of it's vapor barrier properties. It also has a higher R value. Unfortunately it's more expensive too.


----------



## Velosprints (Feb 11, 2019)

Believe it or not, a closed cell product has been our lowest quoted price so far! We live in VA, so it can get cold, but nowhere near the northern states. Would you still recommend closed cell?


Sent from my iPhone using Tapatalk


----------



## schreibdave (Jun 12, 2016)

Velosprints said:


> Believe it or not, a closed cell product has been our lowest quoted price so far! We live in VA, so it can get cold, but nowhere near the northern states. Would you still recommend closed cell?
> 
> 
> Sent from my iPhone using Tapatalk


I'm not qualified to give that kind of advice. Have you checked out Building Science Corp? They put out research on all sorts of building science issues. the search function on their web site doesn't seem to be working now but here's something I found with google.

https://www.minnesotasprayfoaminsulation.com/wp-content/uploads/2013/04/Building-Science-Corp-Spray-Foam-Guide.pdf

It seems to say that in your climate (zone 4) either open cell or closed cell would work. Not sure what they say about the need for a vapor barrier.


----------



## deanpegal (Jan 17, 2018)

spray foam insulation for an entire house would be expensive and as you are doing it by yourself. I would be quite challenging but Best of luck for that.


----------

