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: 117

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

Home Energy Pros

Home Energy Pros was founded by the developers of Home Energy Saver Pro (sponsored by the U.S. Department of Energy,) and brought to you in partnership with Home Energy magazine.  Home Energy Pros is sponsored by the Better Buildings Residential Network.

Latest Activity

Profile IconKurtis Pender and Colin Genge joined Sean Lintow Sr's group
Thumbnail

Best Practices (Residential)

Best Building, Retrofitting, or even Auditing Practices - what are they, what should change, what…See More
2 minutes ago
Kurtis Pender joined Michael Stuart's group
Thumbnail

INFRARED THERMOGRAPHY USERS

This group is dedicated to knowledge sharing and discussion of infrared thermography for building…See More
2 minutes ago
Profile IconKurtis Pender, j. west and Colin Genge joined Norm Bourassa's group
Thumbnail

Multifamily Buildings

For too long there has been relatively little EE focus on multifamily, but some new programs have…See More
5 minutes ago
Bud Poll posted a discussion

How do we pay for the grid?

Ok, so some electric utilities are charging some form of up front and/or monthly added charge for…See More
3 hours ago
Colin Genge's video was featured

Passive House Testing Webinar (Feb 13, 2014)

We covered: - Measuring air leakage in a tight house; - New passive house testing equipment; - Powered flow hoods for accurate measurement of HRV ERV flow ra...
6 hours ago
Colin Genge posted events
13 hours ago
John Nicholas replied to Sean Lintow Sr's discussion Duct Testing - is a change in order? in the group Best Practices (Residential)
"Yes,  I was connected to the AH cabinet.  I find it easier in this area, given the common…"
15 hours ago
Colin Genge replied to Kim Tanner's discussion Blower Door Applications Guide in the group Multifamily Buildings
"This is a great guide that anyone testing with multiple fans should get hold  of. "
16 hours ago

© 2015   Created by Lawrence Berkeley National Laboratory.

Badges  |  Report an Issue  |  Terms of Service