View Full Version : Finished wall needs insulation
09-24-2011, 04:02 PM
I need to insulate a finished wall (first floor). The inside of the wall is covered by cabinets.
I cut a hole in the wall because it was always cold and found that there was no insulation.
I want to know what options I have.
I'm guessing one options is to pull the vinyl siding off and either remove the panels and insulate or blow in cellulose.
Are there any other solutions I'm missing?
Gary in NJ
09-24-2011, 04:29 PM
Spray-in foam insulation. You drill a small hole in the top & bottom of each 16" section. Two holes are used so you don't overfill the section, resulting in a bulged or damaged wall. A wand is inserted in the bottom hole nearly to the top hole (the foam is sprayed from the bottom). As the foam is released and expands the wand is moved down until is comes out of the hole.
quote; A wand is inserted in the bottom hole nearly to the top hole (the foam is sprayed from the bottom). As the foam is released and expands the wand is moved down until is comes out of the hole.
In that case, what is the benefit of the top hole? It will be "closed off" as soon as the insulation spraying starts, and do NOTHING to prevent "overfilling". You can also fill from the bottom up, and then you would know IMMEDIATELY when the cavity is "full".
09-24-2011, 05:50 PM
What you described isn't spray foam, it's pour foam, that isn't how it's done.
09-25-2011, 01:18 PM
This is not a DIY operation. It must be done by professionals using professional equipment and who have the knowledge of how to do the job without damaging your home. Make sure they are licensed and bonded so if there are problems, they will be dealt with.
09-25-2011, 01:35 PM
Seeing how it is only vinyl siding, you would be better off pulling the siding, removing the sheathing and hiring a spray foam contractor.
Pour foam is risky even when pros are involved.
09-25-2011, 03:04 PM
I don't know enough about spray foam or pour foam to venture an opinion on either of them, but if you pull the siding and the sheathing, you could insulate with regular fiberglass and Tyvex. That's still a lot of work. Before you make any commitments, have two or three insulation companies come in and discuss the various options available. You might be surprised at what they can do with situations like yours.
Blowing in cellulose (dense-packed to 3.2lbs, for CT) would be a safer/cheaper retrofit than foam pours, and far better than any fiberglass batt solution. Thermal performance is comparable to half-pound pours and dense-packed is nearly air-tight.
You could get another ~ R1 (whole-wall R) out of it by going with new-school super-fine fiberglass such as Optima or Spider, but only if dense-packed to 1.8lbs or higher (at the low density 1.0lbs minimum recommendation it allows too much convection and doesn't air-tighten very much, but it's still better than batts.) As long as you have vinyl siding you won't need an interior vapor retarder- only standard latex paint, but unlike cellulose the insulation won't protect the wood by buffering winter moisture.
Non-expanding injection foam (Tripolymer, etc) also works and will air-tighten, but despite ~ R5/inch center cavity it doesn't much improve the whole-wall R, and it's fairly vapor-permeable to moisture- similar to fiberglass in that regard. (Again, fine in your climated as long as you have vinyl siding, which is inherently back ventilated to aid drying of the sheathing.)