[ctviggen]

We're looking at having more insulation installed in our house. Has anyone has spray foam installation installed in their EXISTING house, meaning that you currently live in it?  I keep reading the potential for negative effects, see:

http://www.greenbuildingadvisor.com/blogs/dept/qa-spotlight/does-spray-foam-insulation-gas-poisonous-fumes

https://www.epa.gov/saferchoice/vacate-and-safe-re-entry-time-spray-polyurethane-foam-application

Has anyone had spray foam insulation installed in their existing house and have you had any troubles since then?  Did you have to leave during installation, and if so, for how long?

[mcgsxr]

We had our basement sprayed during the finishing project a number of years ago.   About 5 now I recall.

We left for the recommended 24 hours. 

No issues since. 

[benguin]

During a remodel, we gutted the exterior drywall and removed the "R 3.7" insulation (using that term loosely for what we took out) and had a soy based closed cell installed. 

No negative issues that we noted, but it was summer and we had plenty of ventilation.  On the positives, huge reduction in outside sound and very evident heating/cooling improvements.  Plus no creaking/cracking/popping noise in high winds- likely helped structural rigidity.
  Ben

[Rusty Jefferson]

I had if applied to the walls/floors of a 300 sq ft addition added to my existing house.  I wanted to see how it worked because the existing house is concrete block without insulation.  When I get around to renovating the block part I planned to frame up walls around the exterior and spray foam. 

We were able to block off the addition from the existing house during construction but still stayed with friends for 2 days during application.  We also left the foam exposed for a month or more before hanging drywall.

I appreciate the concerns with foam products.  Everything we expose ourselves to from day to day has potentially negative side effects.  It'll probably take years to determine whether these products are harming any of us. I don't fear it but that doesn't mean I shouldn't.

Spend some time at the Environmental Working Group website examining skin care products we use every day and their potential harm to our health.  http://www.ewg.org  Then research (if you can) what's inside the fabrics and fill of the furniture you have in the home.  Fire retardants in your mattresses? Those are known Carcinogens. Unknown combinations of wood products in cabinets and flooring coming from overseas?  Living in America is (potentially) dangerous.

[thunderbrick]

Timely thread.  I'm planning to replace siding and sheathing (asphalt board) on the north side of a 60-year old house soon. 

[Armaegis]

I don't have direct experience, but I have a few friends who do electrical work who hate the stuff because it makes it very difficult to get back in to do work when needed. If it's possible to run conduit, do it. If it's possible to leave gaps in the spray and supplement with fibreglass or whatever around the wires, do that.

[mcgsxr]

+1 on proper planning for electrical, plumbing, future endeavors etc.

I have a few pics here of my basement after it was shot.  It covers everything (wires, pipes etc) so I had that all done in advance, and conduits for future proofing installed prior to the day of foam shooting.





I would do it again (the foam).  I am considering dropping the drywall in the garage and adding foam.  It would very effectively seal the garage (keeping gasses out of the house) and of course increase the R factor in there too.

[goskers]

Please be aware that most houses built using common methods are very leaky.  The potential to run into
issues via sealing your house up without having control of the ‘ventilation’ portion of your HVAC are there. 

With that said, closed cell foam is a great addition to your house.  Focusing on the rim/band joist of your house first is wise.  Doing a flash and batt method where you spray 1” of foam followed up with batt insulation is the most cost effective.  1” will provide the seal necessary while the batt can provide the extra r-value.  Spray foam is rather expensive.

My .02

[Bizarroterl]

We did a remodel a few years ago (kitchen, dining, and living) and that portion of the house was all done with closed cell spray foam.  It worked so well we recently had the master BR done (drywall was off) and had the entire upstairs attic floor sprayed (3" + 12" fiberglass blown).  It fully cures in 24 hours though you may want to plan on being out for 2 days (weekend trip?) just to be safe.

[rpf]

Please be aware that most houses built using common methods are very leaky.  The potential to run into
issues via sealing your house up without having control of the ‘ventilation’ portion of your HVAC are there. 

With that said, closed cell foam is a great addition to your house.  Focusing on the rim/band joist of your house first is wise.  Doing a flash and batt method where you spray 1” of foam followed up with batt insulation is the most cost effective.  1” will provide the seal necessary while the batt can provide the extra r-value.  Spray foam is rather expensive.

My .02

2nd these and the other concerns, and therefore second the flash and batt method (with mineral wool, eg. Roxul, r/t fiberglass), rather than a full spray foam job, if you do want an air tight seal.

[ctviggen]

Thank you all. I've been researching this for years now, and there is a lot to think about.  Closed cell spray foam is very expensive, the most expensive insulation.  I read an article in Fine Home Building that said that open cell insulation (cheaper) has basically the same R value in a wall, because for closed cell, they have to stop before the end of the wall, but open cell can go past the wall and get cut off.  The open cell is therefore very close in R value.  Then you can get into arguments about whether closed or open cell should be used against the roof; some people say one, some say the other, some say either.

And, reading Fine Home Building, they love blown in insulation (eg, cellulose) and thicker walls with thermal breaks.  Unfortunately, in an old home, that's tough to do.

One issue we have is that we have an in-law apartment that my mother and her 6 (old) cats live in. We (my family) can leave for several days, but either my mother or the cats can't.  Now, the in-law is in a different space than the main house, so maybe that helps. 

The real issue is that we have an air handler in the attic, which is a terrible idea.  Even if you add tons of blown in insulation to the attic ceiling, the freaking air handler is subjected to very hot or cold temperatures.  It's idiotic. The only way to get this into the conditioned space is build a room around it or spray foam the attic.  When you have a 4,100 square foot house, that's a big freaking attic and a lot of spray foam.

Will write more once we decide what we're going to do.

[JLM]

Have they solved the dry rot problem with blown insulation?  Lots of places that used it in the 80's have suffered it.

Regarding the flash and batt method:  If the foam insulation is continuous it should be very effective (and remove the dry rot concern).  Think of a styrofoam cup, it drops the scalding hot coffee temperature to warm with a very thin (continuous) layer of insulation.

Surround your air handler with insulation (except for the air intake and exhaust ports which should both be vented to the outdoors).

Personally I don't see the problem in gaming the cats.     I killed two of wifey's show rabbits that stay in the attached garage by running our portable generator (with the doors open).

[Peter J]

Have they solved the dry rot problem with blown insulation?  Lots of places that used it in the 80's have suffered it.

Regarding the flash and batt method:  If the foam insulation is continuous it should be very effective (and remove the dry rot concern).  Think of a styrofoam cup, it drops the scalding hot coffee temperature to warm with a very thin (continuous) layer of insulation.

Surround your air handler with insulation (except for the air intake and exhaust ports which should both be vented to the outdoors).

Personally I don't see the problem in gaming the cats.     I killed two of wifey's show rabbits that stay in the attached garage by running our portable generator (with the doors open).

Blow-in insulation dry rotting?  That's news to me. Can you cite some documentation regarding that, JLM? Cellulose blow-in, both dense pack and loose fill, is commonly used in high performance insulation packages on many structures today.   

As to the rabbits and cats, that seems like a really callous statement regardless of the emoticons.

[macrojack]

ctviggen - I have spent the last few years and an unjustifiable sum retrofitting my 1300 sq. ft. house with net-zero as my goal. Cannot see any justification in owning a 4100 sq. ft. home, much less trying to retrofit it to any reasonable energy standard.
If, as it appears, you have the desire, wherewithal and commitment to live in a highly efficient structure, you would be better served to design and build from scratch with your family's lifestyle preferences and needs custom accommodated, including your mother's present and impending handicaps. Old age spares only the deceased. And as a part of custom accommodations, I would provide for fewer cats. Six is too many for most residential zoning and any practicality.
Set yourself up to be grid-tied initially with an eye toward full energy independence once batteries are sufficiently improved in  pricing, maintenance and cost.
As I am now 70 years old, I despair of being able to reach my goal of net-zero considering the outlay I am facing for windows and doors. By doing this improvement, I am surrendering the dream of building from scratch and probably eliminating the chance that I can ever afford the $12K to $15K I would need to add exterior insulation and stucco. Accepting donations.
.

[sounddog]

One possible caution if you're thinking of applying the foam insulation underneath your roof. Our friend did that and when I mentioned it to our roofer he said it can make it almost impossible, should there be a roof leak, to determine where the leak originates.

[nickd]

While spray foam is most likely the best option, a radiant barrier an be very effective and is far less expensive.
I used the foil/foam/foil stuff that they sell over at “insulation 4 less” on the web. Comes on the UPS truck in rolls. They claim it is as effective as R19. Don’t know about that, but it sure helps in my garage.

[rpf]

One possible caution if you're thinking of applying the foam insulation underneath your roof. Our friend did that and when I mentioned it to our roofer he said it can make it almost impossible, should there be a roof leak, to determine where the leak originates.

Yes, spray foam underneath a roof is a really bad idea for a variety of reasons. You can use rigid foam or Roxul (preferably the latter due to its fire resistance: there are fasteners available to hold it in place) underneath a roof with spacers between the insulation and roofing to allow the latter to dry and be accessible if necessary.

[rif]

We had blown in cellulose blown into the attics and all exteriors walls.  A couple of years later, we had new vinyl siding put in, with tyvek wrap and foam (not spay) insulation.  The latter made a huge difference.  Very noticeable on the heating and cooling bills.  Much more so the the cellulose

Jyst my $0.02

[thunderbrick]

Yes, spray foam underneath a roof is a really bad idea for a variety of reasons. You can use rigid foam or Roxul (preferably the latter due to its fire resistance: there are fasteners available to hold it in place) underneath a roof with spacers between the insulation and roofing to allow the latter to dry and be accessible if necessary.

Seal the attic from the conditioned space, get plenty of attic ventilation, and DON'T insulate directly under the roof deck!!!

[JLM]

Blow-in insulation dry rotting?  That's news to me. Can you cite some documentation regarding that, JLM? Cellulose blow-in, both dense pack and loose fill, is commonly used in high performance insulation packages on many structures today.   

As to the rabbits and cats, that seems like a really callous statement regardless of the emoticons.

No documentation, just examples I've run across after 35 years around construction.  We used blown fiberglass 12 years ago plus house wrap and an extra 1/4 inch layer of styrofoam.  Except for the dryer vent flapping we have to look out the window to know there's a 30 mph wind.

Sorry if I offended regarding cats and rabbits.  Didn't mean to kill the rabbits and I don't know what I intended to say about the cats (my keyboard occasionally gets funky).  But six cats in a well sealed house could be a recipe for odor issues.