My second question is, the consultant is a big fan of blown insulation. The GC says that R19 insultation is adequate and feels blown insulation is fine where you have existing walls but if all there is right now is studs, why bother with blown insulation....?
I am a single mom trying to make an informed decision. I'm certainly no contractor and feel as if I am caught between 2 very different opinions. Any input would be appreciated.
As with most things in life, various insulations have pluses and minuses. The main problem with blown insulation in walls is guaranteeing you've filled the whole space. Wires, etc in the wall may catch the insulation and leave a big gap. Also, is there damage to the dry wall to make openings for installation? You can see fiberglass filling the wall space during installation since it goes up before the drywall. One problem is workers who don't take care about their work may leave gaps around outlets,etc. Also the fiberglass may not fill the width of the stud space if the studs are slightly further apart than normal. One alternative is icyene (sp?) foam insulation. The foam liquid is sprayed on the wall and expands about 100 times. This fills every bit of space. Unfortunately it has to be installed by a trained contractor and is more expensive.
In your case I would go with fiberglass in the walls. Before the drywall goes on, go over the whole wall yourself to fix any gaps left by the installers. Also take a caulk gun and seal any cracks since moving air really ****s out the heat. And get a can of minimally expanding foam (Great Stuff is one brand) to fill narrow gaps that fiberglass won't fit. Be careful with the foam since it may be strong enough to bow studs around windows and doors. Put in one line of foam and give it time to expand. You can always come back to add more foam later.
How about:
Also take a caulk gun and seal any cracks since moving air really cools the inside air.
Nick
Small ranch on crawlspace built late 1980's had one really big vent for cold air return.
Four bedroom on slab built in 1990 with at least two returns upstairs and a big one downstairs.
Three bedroom with basement built in 2000 with two returns each in family room and master bath. One return each in two bedrooms, dining room, and both upstairs and downstairs halls. All returns are very roughly 6x10 inch.
I'll admit that in the latest house, I've come across a few things that I don't understand why the builder did something. The returns were made by putting a vent into the space between studs near the ceiling on an interior wall. The bottom plate and subfloor were cut with a sawzall to make an opening from the upper stud space to the space below. The only sheet metal work for returns is in the basement. I'm not saying this is the right way. It's just what I have.
