This year, I'm thankful for closed-cell foam insulation. Yeah, that's right.

By
Home Inspector with Structure Tech Home Inspections
http://actvra.in/pbM

Yes, you read that right.  I'm thankful for closed cell foam insulation.  Of course, I'm thankful for my family, health, and all that other jazz, but this is a blog about home inspections and home related topics, so I'm going to stay focused on that.  To fully explain why I'm so thankful for closed cell foam insulation, I first need to complain about my house a little bit.

My thirteen-year-old Maple Grove house has an unfinished basement with a walkout; this means about half of the basement walls have a poured concrete foundation, and the other half, the part that's above grade, has conventional 2x6 wood framing.  The foundation walls are insulated at the exterior with rigid foam; this is a great way to insulate a foundation, because it means that the concrete walls will be relatively warm, and the potential for condensation problems will be minimized.  If you want to read more about foundation insulation methods, click this link - foundation insulation.

Fiberglass insulationThe stud walls, on the other hand, were insulated the same way as 99.9% of the houses in Minnesota - with fiberglass batts.  Yuck.  While this is the standard way to insulate a wall, it's also probably the worst acceptable way to insulate a wall.  The photo at right gives a great example of how fiberglass batts are installed incorrectly all the time; just look at those gaps around the junction box.  I've already dedicated a blog to complaining about fiberglass batts, so enough on that topic.

In addition to having fiberglass batts for insulation, the vapor barrier in my basement was basically useless.  Here's how a vapor barrier is supposed to work: to prevent air from passing through the fiberglass insulation and creating moisture problems in the wall, a vapor barrier gets installed.  This consists of 6 mil polyethylene sheeting (aka 'poly', aka 'Visqueen') that has been made airtight; that means caulked, overlapped, sealed, taped, etc.  On a home built today, this will be done quite well.  On a house that's thirteen years old... no way.  The vapor barrier will probably be just about useless.

Unsealed vapor barriers create heat loss.  Just thirteen years ago, vapor barrier were never sealed. It was standard practice to just use a stapler to throw the poly on the walls and leave everything completely unsealed.  This practice allows for air to constantly circulate within the fiberglass insulation, creating a convective loop, which means a lot of heat gets lost through the walls.

I have my 'office' set up in my unfinished basement, so I spend a lot of time in the basement.  During the winter it gets very cold in my basement, despite the fact that I have 2x6 walls filled with fiberglass insulation.  Last winter I kept an electric space heater under my desk to keep my toes from turning in to icicles.

rim joist insulationFiberglass should never be used at rim spaces.  The rim space is the area between the floors of a house; this is an area where it's nearly impossible to install a proper vapor barrier.  Without a vapor barrier, condensation can occur at the rim space, creating mold growth or eventually rotting out the rim space.  This is why fiberglass insulation should never be used here.  On new homes, it never is.  The only type of insulation that gets used on new construction homes in Minnesota is closed cell spray foam insulation; we'll come back to that in a minute.

Unsealed vapor barriers can lead to mold growth.  When a vapor barrier isn't sealed and air is allowed to freely pass through the wall, what happens when warm, moist air hits a cold surface?  It condenses.  My basement stays relatively cool and dry throughout the year, so the vapor drive is really happening from the exterior during the summer.  The walkout part of my basement faces south, so this part of the house is where I have the greatest temperature differential between the exterior and interior of the walls.

During the summer, as humid outdoor air passes through my walls and hits the relatively cool vapor barrier, the moisture condenses.  This summer there was never enough moisture to actually drip down to the floor, but it was enough to leave drip marks in the insulation and allow mold to start growing between the insulation and the vapor barrier.  This wasn't major and I don't have mold allergies, so I wasn't too whipped up about this... but I couldn't allow this to continue.

Mold in fiberglass batts Mold in fiberglass batts 2

Enter closed-cell spray foam insulation.  To address all of the insulation, mold, and vapor barrier issues at the same time, I had the wood framed walls in my basement completely re-insulated about three weeks ago.  I had the vapor barriers removed, all of the fiberglass insulation removed, and closed cell foam sprayed in to the walls and rim spaces.

Foamed walls

I love it.  Closed cell foam acts as a perfect vapor barrier after 2", it doesn't allow for convection, and it has a much higher insulating value than fiberglass.  Now when I walk down to my basement, I don't feel a drastic change in temperature; my basement is only about two degrees cooler than the rest of my house.  I can sit here at the computer without a space heater, and I no longer freeze my toes off.  Life is good.

Having foam insulation sprayed in to the walls was expensive, but it was worth every penny.  Will I ever get a payback in energy savings?  I'm not sure.  I didn't even bother to check the numbers, because my main motivation for this project was comfort.  Saving energy and not having mold growing inside the wall cavities is just a bonus.

Happy Thanksgiving.

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Re-Bloggged 3 times:

Re-Blogged By Re-Blogged At
  1. Russell Proefrock 11/23/2011 11:35 AM
  2. Dan Edward Phillips 11/28/2011 09:55 AM
  3. Dan Edward Phillips 12/12/2011 04:10 AM
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Topic:
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Minnesota Hennepin County Maple Grove
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closed cell foam insulation foam insulation
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Rainer
145,762
Michael S. Bolton
MN Appraiser
Michael S. Bolton,Inc.

Reuben, I'm going to be finishing off my basement and was curious about foam. My concern is the payback, I don't believe I'll be in the house for very long. I'll have to do some kind of cost analysis I guess to see if it's worth it. Good information. Have a great day and Happy Thanksgiving!

November 22, 2011 12:21 PM
Rainer
239,373
Justin Dibbs
REALTOR® - Ashburn Virginia Homes for Sale
United Real Estate

I wish we had that in the lowest level of my home.  It's noticeably cooler than the rest of the house and not so comfortable in the winter.

November 22, 2011 01:18 PM
Rainmaker
162,738
Reba Haas
Team Reba, CDPE
Team Reba of RE/MAX Metro Eastside www.TeamReba.com

what a fantastic post!  I just put in one that was about some energy efficiency tips but this is even more detailed and I love that you put in photos!

November 22, 2011 02:21 PM
Rainmaker
318,011
Jon Quist
Tucson's BUYERS ONLY Realtor since 1996
LONG REALTY

Foam sounds good Always has, at least to me. Batting has never appealed to me. Here a lot of better builders use blown in cellulose. Acts a lot like the foam properties. And fire and termites don't like it, to boot.

November 22, 2011 04:36 PM
Rainmaker
391,817
Shar Sitter
Home Staging and Redesign Minneapolis/ St. Paul, M
Rooms With Style

Ahh...that is so touching Reuben. LOL. But I hear you, somethings we are thankful for are a little out of the norm.

November 22, 2011 06:10 PM
Rainmaker
229,481
Reuben Saltzman
Minneapolis Home Inspections
Structure Tech Home Inspections

Jay - I remember that post!  I just went back and re-read my comments; funny, I just about said the exact same thing today :).  If that house was $4/ sq ft, that's one hell of a large house.

Michael - I think I ended up paying somewhere closer to $2 / sq ft for the walls - not nearly as much insulation is needed.

Mike - definitely.  I spend a lot of time in my basement, and it's great to not be cold.

David - open cell foam will never act as a vapor barrier, it has about half the insulating value, and it costs about the same amount of money.  The one benefit to open cell foam is that it works better for sound dampening.  The guy that did the foam at my house has a nice discussion of open cell vs closed cell foam here - http://getfoaminsulation.com/?p=142

Tyler - the best thing to do for your attic would be to have about 2" of closed cell foam blown in, and then have it topped off with cellulose or fiberglass.  I wrote about this here - http://www.structuretech1.com/2011/03/best-way-to-insulate-an-attic/

November 22, 2011 09:38 PM
Rainmaker
229,481
Reuben Saltzman
Minneapolis Home Inspections
Structure Tech Home Inspections

Charles - what brand of foam?  I have no idea.  I sent an email to my insulation guy to find out.  I'll get back to you on that.

Tammy - I bet they're happy with it.

Eileen - I agree.  My dad had foam insulation installed in his attic about a year ago, and it made a dramatic difference.  

Richie - I've heard of foam being installed from holes in walls, but I don't know of any contractors that offer it.  The 'traditional' foam needs to be applied in open air to allow it to cure properly.

Michael - If I were only going to be in my house for a couple of years, I probably wouldn't have made the investment either.

November 22, 2011 09:42 PM
Rainmaker
229,481
Reuben Saltzman
Minneapolis Home Inspections
Structure Tech Home Inspections

Justin - rigid foam boards work quite well too, but they're a lot more labor intensive.

Reba - thanks!

Jon - I'm a big fan of cellulose as well.  What do they use at the rim space in your area?

Shar - Lol, thanks :)  

November 22, 2011 09:46 PM
Rainmaker
808,064
Lyn Sims
Schaumburg Homes
RE/MAX Suburban - Schaumburg IL Real Estate - Northwest Suburbs of Chicago

Reuben: A favorite of Mike Holmes also. Even though it might be more expensive, I think in the long run it's creates just a better environment which you've already experienced.  I really think that in this day & age it should be standard in home building.

November 23, 2011 09:36 AM
Rainmaker
229,481
Reuben Saltzman
Minneapolis Home Inspections
Structure Tech Home Inspections

Lyn - I totally agree.  It's already the standard for rim spaces in Minnesota, and it's getting to be more and more popular for other uses.  

November 23, 2011 11:37 AM
Rainer
275,002
Kimo Jarrett
Kimo's Lifestyle Solutions
WikiWiki Realty

Interesting illustration and information, so what's a reasonable price to pay for the insulation? How is the cost calculated, etc? Thanks for your timely reply.

November 23, 2011 12:46 PM
Rainmaker
267,830
Travis "the SOLD man" Parker; Associate Broker
email: Travis@theSOLDman.me / cell: 334-494-7846
Team Linda Simmons, Enterprise, AL 36330

We had a rep for a foam company speak at a recent S.T.A.R. class, and he said that the closed cell foam would add an extra 100 mph strength to the places applied. Even if that is exagerated a bit, that extra protection in the Hurricane prone areas like I live in is worth at least checking into. 

November 23, 2011 01:33 PM
Rainmaker
141,299
Marshall Brown
BSEE, CHI
Mid America Inspection Services, LLC

You have to wonder why blow in foam is so expensive when the basic materials are relatively cheap. I know the machines are costly but still would last a considerable time.

It seems to me a lot, if not most, of energy saving methods and devices are priced so that the sellers get the saving amount, not the buyers. I learned that is Cynicism-101.

In fairness, I should note Foamitgreen has a DIY kit for abount $1.10/sq.ft.

https://www.sprayfoamdirect.com/products/component/vmcchk,1/option,com_virtuemart/Itemid,1/

November 23, 2011 02:12 PM
Rainer
28,445
Jayson Holland
Jay Holland
RE/MAX

Another great post! Love it. Thanks again.

November 23, 2011 02:19 PM
Rainmaker
452,213
Jan Green
RE/MAX Excalibur Scottsdale REALTOR®, GREEN®
Scottsdale, Phoenix, Cave Creek, Carefree, Fountain Hills

Am a huge fan of spray foam insulation and recommend it to anyone I chat with.  Here in AZ our ducts are in the attic. Our attics can rise to 150 degrees in the summer - no joke!  Imagine spraying the lid of the roof so that our attics only get to 10 degrees over the interior?!  What a huge benefit to HVAC systems from having to work so hard!  Great post!

November 23, 2011 06:55 PM
Rainmaker
626,489
James Quarello
Connecticut Home Inspector
JRV Home Inspection Services, LLC

I agree about the closed cell vs. open. If I were to use foam it wouldn't be anything but closed. I recommend closed cell for rim joist for my energy audit customers. All builders I see here still use fiberglass. 

November 23, 2011 06:57 PM
Rainmaker
628,967
Stephanie/Bob The Ruiz/Miller Team
The Ocala Dream Team
Keller Williams Cornerstone Realty

Hi Reuben,  Excellent post and a great educationon insulation and the different types

November 24, 2011 08:04 PM
Rainmaker
563,424
Chris Smith
South Simcoe, Caledon, King, Orangeville Real Esta
Re/Max Chay Realty Inc., Brokerage

Reuben, great information.  I need to address leakage in my home envelope and this might be a way to insulate as well.

November 29, 2011 12:53 PM
Rainmaker
347,753
Sylvie Stuart
Home Buying, Home Selling and Investment - Flagstaff, AZ
Keller Williams Check Realty 928-600-2765

Interesting! Thanks for the info on the comparison. I didn't know that fiberglass batts were that problematic. It's good to know!

December 19, 2011 08:27 AM
Rainmaker
261,430
Wayne B. Pruner
Tigard Oregon Homes for Sale, Realtor, GRI
Oregon First

This is good stuff. If I was to be an insulating contractor, this would be my specialty.

June 19, 2012 10:08 AM
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Rainmaker
229,481

Reuben Saltzman

Minneapolis Home Inspections
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