Retrofoam House Insulation

[jyl]

Question about insulating an old house.

My house was built in 1911. Wood frame. Not insulated. Wainscoting and built-ins cover most of the downstairs walls.

I'm interested in this injected foam process. Spray Foam Insulation | RetroFoamâ„¢ - Foam Insulation for Existing Homes

They claim
- Non flammable
- Mold resistant
- No off gassing
- Non expanding
- Sound and temperature insulation
- 4" is R15, 6" is R27

What do you think? See the video.

[masraum]

I've heard/read about that type of stuff before (spray in through small holes to fix old construction), and it seemed like a good deal. It might REALLY SUCK if you ever need to do wiring work in your walls. But, it sounds like the best option. I, obviously, don't have any personal experience.

ghase (Gary) is in that biz.

[Evans, Marv]

I'd have to agree with removing the inside wall covering & insulating. If your home was built in 1911, there are probably electrical and plumbing issues to be addressed and upgraded too. I doubt you'd like to anticipate having to go back to fix those as they popped up over time. Sounds like the beginning of a pretty big project.

[billybek]

Had just watched a Marketplace episode that covered the use of foam insulating and problems associated with it.
Will see if I can find a YouTube link for it later.
I would guess that a large percentage of these jobs go without a hitch. I did tear out the drywall and insulation on my 50 year old bungalow and re insulated and was able to run ground wire to the outlets.
Installed a real vapor barrier and then hung new drywall.
I used Roxul mineral wool insulation. Great stuff. Highly recommended.
Messy but worth it in the end.

[GWN7]

This might be the Marketplace video: https://www.youtube.com/watch?v=0Hh5MYv7lWc

[john70t]

I looked into the retrofoam product and I like what I've seen so far:
-It's slow rise. It will not blow out drywall when installed correctly.
-Applied from the inside they will have to drill a series of drywall holes to allow for over-expansion and completeness. Easy fixes.
-Low off-gassing. I got ill from the limited amount of 3M blue closed-foam I had installed.

Air leaks are much more important than R value.
An energy audit with thermal camera and blower door test will find the source of loss.

For new/open construction I also looked into:
Home | Airkrete - All Green Spray Foam Insulation!
Cementitious Foam Insulation Gets a Second Look - My Home Science
Mice can't chew through it. Fire doesn't burn it.

[jyl]

Ripping off interior walls is not an option.

"My house was built in 1911. Wood frame. Not insulated. Wainscoting and built-ins cover most of the downstairs walls."

Trapping moisture would be a worry in the PNW climate.

Electrical has all been done. Yeah, I wish they'd added a few more outlets but I can live with it. Plumbing and HVAC all done too.

[john70t]

Afterburn has a good point.

Wood needs to breathe, and the PNW has a lot of exterior moisture.
Normally there is a warm and dry out-flux of air which solves a lot of these condensation problems.

Adding a solid barrier would create two separate zones.
Exterior sheathing (such a cedar shingles) which were previously ventilated slowly and purged in the past might not be anymore.

Maybe more breathable or a lesser insulation might be better?

(Just a thought. I don't know.)

[DanielDudley]

I have done foam board insulation on the outside of houses, and it does have a lot to offer in that it is non invasive and you can live in the home while it is being done. I usually put up the board, tape and seal all of the joints, and then put up 3/4 inch wood furring strips that are tied into the studs to carry the siding. Often new energy efficient windows are installed at the same time, mounted over the 3/4 inch spacers. These spacers are also usually vented from top to bottom. This give longevity to your siding, but also creates a chase for heat to rise in. Two inches of rigid foam seems to be the sweet spot, but many people here choose to go to 4 inches, so you can see why you would retrofit windows flush to the outside. This is a super effective system when done correctly, but it is very labor intensive and requires a total remodel of your exterior.

I did not do this to my own house. Instead, I cleared the attic and had spray foam sprayed to rafter bays. Then I repaired my 8 inch timber frame sills down at the foundation, and sealed them to the stone. after that, I made sure that all wiring in my outside walls was up to modern standards, and I had blown in cellulose installed. Modern cellulose machines blow it in at a higher rate of power and pressure, so it tends to fill the cavities better and settle less. The company that did mine put holes every three to four feet vertically, so I am sure I got good coverage. The foam company also sprayed around the inside of my sills in the basement to seal that better. As an additional step, I also went around the inside walls of the house and made sure any cracks around windows or baseboards were caulked and sealed.

Originally, I was also planning on putting 1 1/2 inches of rigid foam board on the outside of the house and residing, and planning on retrimming the original windows to match that siding. However, I found that the insulation as installed was SO effective, and my energy usage so drastically reduced, that I never bothered to do that.

Obviously you need to keep up with the exterior of your house, but in general, your interior walls and particularly the paint will act as a vapor barrier. Also, you don't want the insulation to get wet, but guess what ? You don't want any insulation to get wet. That is just standard procedure. Also, open cell foam or blown in cellulose does breathe, so it will dry out if it had to, assuming that proper repairs are done to deal with any problems you might find in the future.

No system is perfect, but I can tell you that any improvement to the insulation of your house that you do now will add to your future comfort. Some people blow up to two feet of cellulose into thee attic space, but we wanted foam on the rafters because we use our space. Obviously the house is warmer in the winter, but you don't always notice that, as you would just turn up the heat. What we noticed is that the house is much more comfortable in the summer, particularly the second floor, which we used to refer to as the easy bake oven.

If I had up to date wiring inside my outer walls, I might consider spray in foam, and I think it is a no brainer for new construction. Otherwise, I would consider cellulose. The point is, it isn't always about what you use, or if it is the ''best''. The point is, you want to do something, because whatever you do, if it is done correctly, will make for a substantial and immediately noticeable improvement in your comfort and energy use.

[jyl]

The challenge I have is that I really don't want dozens of large holes cut into the wainscoting or through the built-ins. This seems to make blowing in insulation impractical, at least for the ground floor. I was interested in this foam technique because it seemed to require only small holes. But I guess cutting dozens of 2" holes in wainscoting isn't really better than cutting 4" holes.

[island911]

Look for other ways to access the wall cavities. Perhaps from an attic space. I'll add, that even dropping in a bunch of styrene foam balls, or packaging peanuts, or whatever, will help insulate; even if not a 100% fill, it will still slow the heat transfer.

Oh, and it's supposed to be a cold winter. Global warming, doncha know. .

[GWN7]

Originally Posted by jyl

The challenge I have is that I really don't want dozens of large holes cut into the wainscoting or through the built-ins. This seems to make blowing in insulation impractical, at least for the ground floor. I was interested in this foam technique because it seemed to require only small holes. But I guess cutting dozens of 2" holes in wainscoting isn't really better than cutting 4" holes.

My first house had no insulation. Wood exterior siding. I did cellulose insulation blown in to the 2 X 4 walls. I rented a machine and drilled 1" holes between the studs. I dropped a fishing weight on a line to make sure the cavity went all the way down to the bottom. If it didn't I drilled another 1" hole below the blockage. Getting the right amount of cellulose moving thru the hose as a bit of a trick and the yard looked like a snowstorm had hit in September. To fill the holes I had drilled I bought a bag of 1" Styrofoam plugs that were sold for just that purpose. I dabbed matching siding paint on the plugs to protect from UV rays and to hide them. Eventually I stuccoed the exterior of the house and they were not noticeable at all.

[cashflyer]

As mentioned in the other thread, and here...

The foam bonds to everything it touches.
Including wires and pipes.

It is not "non-expanding" - it is "low expansion".
The foam still pushes into every opening it can find.
Such as switch boxes, junction boxes, etc.

All future remodeling will be a pain in the ass.

I had spray-foam insulation done by a local company, in a garage structure. I think it is a somewhat different process (spray vs pumped) however they both have a lot of the same characteristics. What I can tell you is that I am glad I only had it done in the garage, and that I will never have it done to another structure.