attic insulation

my house is 25 yrs old and needs to have insulation added ( i live in northern California ). my question is:

is this something i can do myself with the same results as hiring a company? is it worth my time and effort as far as saving costs?

i've been told to buy the insulation at Home Depot and they will give you the machine ( to blow it in ) for free.. i imagine the machine is less than ideal. lol that is another question, should i get the blown in type? ( which i have now ), or the type you roll out?

anyhoo, what should i look for as far as what kind / type of insulation? are there different brands / types that are better than others?

thanks for any help FH

Reply to
FH
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The blown in insulation is generally considered better because it fills in all the small cracks and holes that a roll type might miss. It seals air leaks better. It is also easier to put in most locations, assuming you have access to one of the machines.

Reply to
Joseph Meehan

How good is your attic access, and how fat are you? Blowing in insulation requires that you get to all parts of the attic. If the spaces are small and you are large, that can be a problem. You need an emaciated teenager, and hope he understands the instructions. The ideal situation is to send your 12 to 14 year old son or daughter into the attic with the hose while you shout directions.

The blown-in cellulose has the advantage of greatly reducing air infiltration and will result in a more energy efficient house. However, you have to keep insulation away from any recessed electrical fixtures, chimneys, gas appliance vents and eave vents. Depending on the house, that can entail building a lot of sheet metal dams and being careful where you blow it. With the roll-out type, you can just cut it back and tug it away from places it doesn't belong.

The blower will work good, but it is not automatic. It will take somebody to feed the bundles of insulation into it while the person in the attic directs the hose. Both people need to wear a respirator and goggles. It's not particularly hazardous, but you need something to thin the air out so you can breath it. Blown insulation is not itchy, rolled in usually is.

When I did my house, I combined a shake roof tear-of and roof sheathing job with an insulation upgrade. I just walked around on the skip sheathing and blew it into place. When I needed to install a dam, I pried up some 1x4 and dropped it in where it was needed. For eave vents, I just blew the insulation in and raked it back so the vent was open. That, and replacing the old aluminum single glazed sliders with a set of U-36 windows, made an immense difference in the comfort of the house.

Yes, there are better and worse. The lumber yard ran out of the good stuff and sold me some stuff that wouldn't fluff properly in the blower. I took it back and found the good stuff somewhere else. I don't remember the brands, but if it comes out of the blower lumpy, take it back.

Just about anywhere that sells insulation will loan you a blower for free.

Reply to
Larry Caldwell

thanks for the info, i did fail to mention that i plan on putting on a new roof, so access would be easier.

Reply to
FH

thanks Phisherman, see you at the cleaning newsgroup lol

Reply to
FH

I trust you have checked the price of having the job done against the cost of material. 10 years ago I had R-30 blown into the 1800 sq ft attic spaces of my house and the cost difference was small. to small to be worth the nasty job. Being outside helps inside a summer attic is like when i was in Viet Nam. Louis

Reply to
stan100

just got finished blowing insulation into my attic this weekend. Around here insulation companies charge $500-$600 to do the job, cost me around $130.00 and 2 hours of labor. I thought that blowing in insulation was going to be a big job, but after doing the research on the internet, it really wasn't. The biggest problem was finding someone to help me haul a pallet of 30 bags of insulation out to my car @ Lowes.

If you do the job yourself, make sure the machine has a restricter plate(helps to break up the bags of insulation). We had to take one machine back because it was clogging up - turns out it didn't have the restricter plate in it(this was for the Predator brand of insulation blowers).

We now have a comfortable 15 inches of insulation in our attic...On to the next project!

My 2c,

Matty

Reply to
Matty

I waited until early spring to do the job. I recall it was a nasty job. I used a 1/3 sheet of ply, a box cutter, trouble light, dust mask, long sleeved shirt, and a long pole to fluff the insulation. I laid the batts over blown-in insulation. I think it cost me around $200 for a 30x25 foot attic area for the no-itch R30 batts. Get the thickest stuff you can find/afford.

Reply to
Phisherman

In article , mark Ransley ruminated:

Sigh. Cellulose insulation is treated with a flame retardant and water repellant. That's why it's grey and stiff rather than looking like flakes of newspaper. It does pack down a bit when it gets wet, but no more so than fiberglass.

Especially if you like lung cancer and emphysema. One advantage of cellulose is that it's about as innocuous as possible. One reason I probably can't breathe as well as I should be able to is because of all the itchy fiberglass I inhaled while running wiring in hot fiberglass-insulated attics back in my electrician days.

One advantage of blowing cellulose vs. laying more batts of fiberglass is that you don't have to spend as much time in the hot attic (though definitely do wear the respirator because attics are full of dust that you don't want to be inhaling, such as the disintegrated rodent droppings that carry Valley Fever and hantavirus).. The other advantage is that it seals better than fiberglass, preventing drafts from coming up between cracks in the insulation. It serves as its own vapor barrier, basically. The main disadvantage is that you can block your soffit vents with it and mess up your attic ventilation, which will cause serious problems in a cold climate area (fewer problems in a hot climate area, mostly just higher cooling costs). After looking at the pros and cons of various attic insulation materials I came to the conclusion that cellulose was the preferred insulation material if you were going to be putting insulation on the floor of the attic.

Reply to
Eric Lee Green

thanks everyone, all of your opinions really helped, i'll take a lot of the advice here.

FH

Reply to
FH

I did the same thing, minus the 1/3 sheet of ply (and I had the bruises on my hips and knees to prove it), but in January, the best possible time of year to do it in western New York. Freezing up there, but I warmed up pretty quickly! Nasty, nasty, nasty job that cost me about $400 for R25 unfaced rolls over a 50x25 space.

Reply to
xymergy

And high roof replacement costs. The primary thing that causes deterioration of 3-tab roofing is heat, and attic vents are critical for maintaining low attic temperatures during hot weather. If your area is hot and sunny, you need LOTS of attic ventilation to keep your roofing from breaking down.

Reply to
Larry Caldwell

Actually, according to studies done with a variety of technologies that result in heat not entering the attic in the first place, such as radiant barriers and insulation at the roof line, it was found that shingle color, not venting or attic temperature below the roof, was the most important detirminant of shingle temperature. Reflecting

100% of radiated heat back at the roof deck and shingles resulted in a 5 to 8 degree rise in shingle temperature, i.e., raised shingle temperature from approximately 150 degrees to approximately 160 degrees for plain old gray shingles, in one study done in Las Vegas NV. The difference in life span is not likely to be significant, they found, given that darker-colored shingles were already at that higher temperature.

This is likely to be true in any climate where radiant heat gain and loss is the primary mechanism for heat gain and loss at the roof level. Conduction of heat through the roof deck, and from thence convection via attic venting, is a relatively insignificant source of heat loss for shingles in hot sunny climates, these studies found. Thus shutting off the conduction/ convection heat loss channel does not result in as large an increase in shingle temperature as you would expect.

But: For an attic where insulation is on the attic floor, blocking the soffit vents with excessive insulation is *still* a Bad Idea even in a hot climate where condensation at the roof deck is not an issue, since it increases attic temperature and thus increases heat gain via the air handler and HVAC ductwork.

Reply to
Eric Lee Green

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