Insulation

[inquisitive]

Has anyone hired someone to put insulation in a house? I've heard it can cost several thousand dollars but I have a relatively small place (condominium) and don't see why I couldn't apply the 80/20 rule and get 80% of the benefit at 20% of the cost buy using cheaper materials or alternative forms of insulation, etc. The main problem is likely areas where cold air leaks in (maybe I should have a handyperson come first) and less need for external insulation being pumped into the walls or however it works.

[samclem]

Yes, I've added insulation to my attic. It was relatively simple, and it seemed to help reduce our heating bills. The snow on our roof is usually among the last to melt in our neighborhood, so I'm pretty sure I've got good insulation and good attic ventilation (also important).

Depending on the situation, weatherizing and adding insulation can be a two day, easy project or a monumental headache. Adding insulation inside stud walls that are already finished is a big job and the payback period is long.

If you do a search on this site you should find some helpful discussions. Here are a couple of previous discussions on attic insulation. I'm a fan of blown-in cellulose: It's dusty, but fast and effective.

Finance Dude's Attic Insulation Thread

joesxm's attic insulation thread

[kumquat]

Depends where you live and how your house is built.

If you live in a cold climate (winter temps near or below zero) insulation is not enough. You also need a vapour barrier so that your insulation stays dry. I doubt if anyone can give meaningful advice without knowing your approximate location.

FWIW, my house here in the frozen north (north of Montana) is built with:

• 2X6 exterior walls (6 inches of fibreglass)
• 4 inches of Styrofoam on basement walls
• 15? inches of cellulose in attic

All of this has a 6 mil (?) poly vapour barrier on the warm side. The vapour barrier is there to keep the insulation dry (as well as to stop air leaks).

Installing a vapour barrier in an uninsulated attic is a PITA but not that challenging. Installing one in an outside wall is more than a PITA (and costs rise accordingly).

Where are you, what temperatures are you insulating against and how (when) is/was your house built. No answer is correct without the right input.

[My Dream]

They say insulation is important but air sealing is vital. It's much less costly to air seal your home and you'd be surprised at the benifits. I just increased our attic insulation from R24 to R60 and instantly noticed the benifits. I don't think the total benifit was from the increase in blown in fiberglass batt insulation, I believe the 3 cans of spray foam to seal the 16 holes I had from drain vents to electrical boxes. I had a vapour barrier in the attic but when the builders installed either light fixtures or ran wires for the switches they broke through the vapour barrier to run lines or install electrical boxes.

Total cost to air seal 16 holes in the attic $21.00
Total cost to increase attic blown in to R60 $487.00.

Upstairs temperture raised 2 degrees F. and cost savings in natural gas bill.

[travelover]

Depending on your physical ability, you can do much of the sealing yourself. There are gaskets that you can buy for outlets and switches on outside walls. Windows can be tightened up with adhesive backed foam strips. Basement rim joists can be caulked and insulated easily. And wire and plumbing holes can be filled with expandable foam from a can.

Even rolls of insulation are not too bad to work with. Some fiberglass types even come in a plastic cover to minimize the itch.

Retrofitted wall insulation and new windows have a long payback time.

[Westernskies]

Get a few bids from insulation contractors- with construction down all over the US, contractors are very aggressive on pricing. They buy the materials cheaper than you can, many are willing to pass some of the savings on to the customer to keep their crews working.

[samclem]

Quote:

Originally Posted by kumquat Depends where you live and how your house is built. . . . Installing a vapour barrier in an uninsulated attic is a PITA but not that challenging. Installing one in an outside wall is more than a PITA (and costs rise accordingly). Where are you, what temperatures are you insulating against and how (when) is/was your house built. No answer is correct without the right input.

I agree. The vapor barrier is important. One way around the hassle of installing a plastic vapor barrier (say, into an existing finished wall or under piles of insulation in the attic) is to use a paint or primer that impedes the flow of water vapor. The best (IMO) is Zinsser BIN primer. It stinks (open the windows), but will produce a 0.4 perm barrier, which is usually good enough. Painting the interior walls and ceiling is often a lot simple than installing any other type of physical barrier.

The biggest moisture problems usually come not from the transport of moisture vapor through materials, but from mass transport of water vapor due to opening, cracks, and leaks. A single crack or opening can transport many quarts of water into a cool stud bay over the course of a year, much more water than could gain admittance through a typical wall with a few coats of latex paint (maybe 3-5 perm).

As MyDream said, the best bang-for-the-buck is a few tubes of good caulk, some "Great Stuff" expanding foam, and a few hours of time.

[W2R]

Quote:

Originally Posted by samclem The best (IMO) is Zinsser BIN primer. It stinks (open the windows), but will produce a 0.4 perm barrier, which is usually good enough.

Oh good, then it isn't just me! I thought I was over-reacting to the stink.

In 2008 I repainted a tiny, very cramped, windowless toilet-and-shower room, including the ceiling and upper parts inside the tiny closed shower, with Zinsser primer before painting, and it was tough to do due to the stench.

I didn't do it for a vapor barrier exactly. I had just removed the (dark purple) wallpaper and I was worried about mold developing on the walls in the shower room, so the guy at Lowe's said that was the way to go. Guess he was right - - my beautiful new ivory colored walls in there do not show any sign of mold.

[Nords]

Quote:

Originally Posted by inquisitive Has anyone hired someone to put insulation in a house? I've heard it can cost several thousand dollars but I have a relatively small place (condominium) and don't see why I couldn't apply the 80/20 rule and get 80% of the benefit at 20% of the cost buy using cheaper materials or alternative forms of insulation, etc. The main problem is likely areas where cold air leaks in (maybe I should have a handyperson come first) and less need for external insulation being pumped into the walls or however it works.

"This Old House" recently did an "Ask TOH" video segment on the different types of insulation and their installation methods. It's worth watching the videos and reading the articles before subjecting yourself to the tender mercies of a contractor:
Search | insulation : This Old House

Your local weather is going to influence your decision, although I doubt you'll be installing radiant foil to keep the heat from getting in...