Hi out there. I have been running into customers that want to upgrade their wall insulation, but have batts in the walls. In checking with local insulation companies, one says he has foam injection system that works but is $2.00 a sq. ft., the other says there is nouthing he knows of that works. Let me know whats going on out there, so I can pass good information on to my customers.

Have a Great Day!!!!!!!

Views: 146

Reply to This

Replies to This Discussion

There are foam companies that will add foam to existing batt insulation, but I'm a skeptic and would want some guarantees and lots of IR pictures.  Maybe even a few addresses where this has been done before so I can look with my own camera.

Improving 3.5 inch walls is difficult.  If the foam can be done and done right, maybe, but at $2 a sq ft a 1,500 sq ft ranch would be around $2,500, I would run some numbers to see if that works.

In the long run, I always look inside and outside to see if other work is in the near future.  If new siding will be needed soon, then adding rigid foam under the siding might combine to be a lot less expensive.  If inside renovations are planned, padding out a wall, electric, windows, yada, yada, may also be an option.

One of the problems with adding foam to an already insulated wall is that the increase is not all that much and the existing fiberglass actually gets in the way reducing the quality of the new install.  So you end up going from an 11 or 13 cavity to a 15 or 18 cavity.  It would be better if the fg wasn't already there.  Those numbers came from my back pocket area so take your own guess, but they illustrate that the improvement isn't all that great.  Adding a couple of inches of rigid over the outside with new siding also covers from foundation to top plate along with all of the thermal bridging.  Much more impressive results.

Bud

Thanks, kind of what i was thinking. Lets see what others think.

I'm going to back Bud on this one. Spraying in foam and hoping it will effectively fill in around the FG is essentially hopes and dreams kind of thinking.

In a case such as yours, the best bet is to tighten up where you can, add insulation to places like the rim\band joists (if exposed), and begin to plan for a more comprehensive project in the future (where wall insulation is combined with interior renovation and\or siding replacement). 

In my neck of the woods, most houses are faced with a brick veneer (with no insulation in the walls), so the only real way to approach this is to talk to them about making a mess in their houses and them becoming okay with this over time. By "this" I mean the mess that typically accomodates drilling into the sheetrock\plaster, installing cellulose or icynene, and then patching up the holes used to install the insulation. 

Patrick

RSS

Videos

  • Add Videos
  • View All

Twitter

Latest Activity

Profile IconBrad Cook, Juan M San Miguel, Marla Meyer and 2 more joined Home Energy Pros
12 hours ago
Chris Clay posted photos
17 hours ago
Chris Clay replied to Blake Shurtz's discussion Testing spillage on induced draft furnace?
"Monitor the pressure in the vent, if its positive in the vent for more than a minute it is most…"
18 hours ago
Chris Clay replied to Blake Shurtz's discussion Testing spillage in mechanical closet?
"You can stand outside and read pressures. Be sure to have extra hose as you need CAZ wrt outside…"
18 hours ago
Chris Clay liked Blake Shurtz's discussion Testing spillage in mechanical closet?
18 hours ago
Diane Jackson posted photos
18 hours ago
Amber Vignieri posted a blog post
19 hours ago
Evan Mills commented on Tom White's video
Thumbnail

The Impact of Green Buildings on Cognitive Function

"Good to see work like this going on.  Findings seem qualitatively consistent with what…"
yesterday

© 2016   Created by Lawrence Berkeley National Laboratory.   Powered by

Badges  |  Report an Issue  |  Terms of Service