adding insulation

[goodoleboy]

I plan on adding insulation blown in type to my attic.Im gonn a pay about $600 for a 1600 sf home.

Hopefully it will cut my heaqting bill this winter and there is a tax rebate offered by the goverment which is not my reason but every bit helps.

Any real world experience?

 

[Matt_S]

Do it. I did last year and the payback has been significant and swift. Despite the heat this summer, my electric bill never went over $80. My gas bills last winter were the same monetarily as the year before, but gas prices were much higher, so I definitely saved.

My house, like yours, is 1600 sf, ranch style. It had R11 fiberglass bats in the attic. I added enough cellulose to bring it to about R50. One advantage to the cellulose is that it can seal drafts once it settles. Between that and the added R factor, my house is MUCH more comfortable now.

 

[Larry the Cable Guy]

I just did this a week ago. Too soon to measure the results. It is a MESSY job.

Spent about $600 for a 1,700 s.f. house (63 bales).

You will need LOTS of light, good goggles and several good dust masks.

 

[Schmoe]

You can also rent, or they will let you borrow it for free depending on how much insulation you buy, machines out and do it your self. If you get the recycled newspaper, non-flammable stuff, the dust isn't too bad and has about the same R value. Just make sure you don't blow insulation over the side vent holes or your attic won't breath and then you'll start seeing moisture damage.

 

[1sttruck]

'Doing it right' means making sure that you seal sources of air infiltration and adding a vapor barrier, but that's a lot of work. I scooped out the blown in that we had in the attic, it wasn't up to the 2x4 trusses in most areas, swept, vacuumed, used a LOT of spray foam and caulk, put down vapor barrier paint, added urethane board insulation at the edges of the attic as there wasn't room for other types, and then laid fiberglass batts to about a R48 minimum (R25 and R13). It was tedious cutting and placing, and if I had to do it again I'd use batts in the large areas that are easy to place, and use spray in elsewhere. You'd still need to use urethane board at the edges though. If you have ice dam problems add 1in of urethane board to the roof sheathing, inside teh attic on under the overhang, at least for several feet from the edge of the roof.

 

[parrothead]

This thread brought up something I've wondered about since the first time I ventured up into my attic, vapor barriers. My house new(er), built in 2003 and all they did was blow loose fiberglass insulation in the attic and did not use any vapor barrier between the drywall ceiling and the insulation. I live in Michigan where it gets pretty cold. In the 2 winters I've been in the house I haven't had any problems with ice dams and my house is very comfortable. So the question is; is a vapor barrier required in the attic when blown fiberglass insulation is used?

 

[labman]

there are different schools of though on that. One of the things you must look for is condensation on the roof sheathing. After I upgraded my side walls, I ended up with a big condensation problem in the attic. I was retaining much more of the warm, moist air in the house, and it was migrating through my non vapor barrier ceiling. I have controlled the problem using several tactics. Fanatically find and plug holes. add ventilation to the attic. I removed all the soffit on the north side of the house where the problem was the worst. I put back all aluminum perf. I added ridge vents. I also cut holes in the sheathing in the gable ends to allow the wind to blow in through the vinyl siding. I have applied the vapor barrier paint to part of the upstairs ceilings. All that pretty well fixed the condensation problem.

Even if you don't have condensation problems, adding the vapor barrier paint should keep more moisture in the house, better for your nose.

 

[Matt_S]

quote:

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Originally posted by Larry the Cable Guy:
The worst part is trying to keep the stuff out of your eyes in the white-out conditions in the attic...lift up the goggles to get a peek and the stuff gets blown into your eyes when you exhale through the mask...FUN!

Steve

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There is no doubt that blowing in cellulose is a MISERABLE job. You ABSOLUTELY need goggles and a dust mask. You also need someone reasonably strong to load the machine. The bales aren't very heavy, but they're big, bulky and awkward to load into the hopper. The hopper itself comes up to shoulder level on most people, adding to the awkwardness. I'm definitely glad I did it, though.

 

[Larry the Cable Guy]

Yes it's miserable but fortunately it goes fairly quickly (about 20 bales per hour). The machine that we had was only about waist high so loading the hopper wasn't too bad.

Also, plan on doing it on a cool day!

So where is "Bob is the Insulation Guy"?

 

[1sttruck]

"So the question is; is a vapor barrier required in the attic when blown fiberglass insulation is used?"

Nothing is required, it's just a matter of what type of problems you're willing to live with. Cavemen built our place, and the guys putting in the insulation apparently stuck their pointed little heads up thru the attic entries, sprayed the blower around and moved on. There was zero insulation in the corners, just bare drywall which was the ceiling. The rest barely got up to the 2x4 trusses. Every spring we'd have a army of bugs spreading from every hole into the attic. Above the holes in the attic the wood was molding where the warm moist air hit the cold attic and condensed. The bathroom fan vent was hooked to a few feet of flexible ducting, which was wired to point at a vent. During a cold snap it acted like a condensation chamber and water dripped from it, enough during an extended cold sanp to crumble the ceiling around the fan. Needless to say heating bills were high, it got very hot in the summer, and there were always cold spots in the winter.

I also had to work on the crawl space as the house acts like a big chimney, drawing cold air in, typically from low spots, the living space warms and humidifies it, and then it tries to escape higher up. Ceiling holes, window seams, door frames, outlet boxes, etc., all allow warm air to escape, which then condenses when it eventually hits cold building materials. The crawl space was so open that we had frogs, slugs, snakes, mice, and carpenter ants living in there. Not no more.

 

[TooManyWheels]

The vapor barrier question has to be considered in light of the complete picture of the weather patterns, construction and ventilation practices where you live. Google the insulation manufacturers, building practice research councils and regional energy co-op groups for the standard practices in your area.

 

[mechtech]

Don't forget a few electric vent fans. Get good ones.
My brother in Texas re-insulated, and put a number of good fans in, and it helped very much to keep the house cooler, with much less expense for he A.C.

 

[Winston]

Be carefull with the vapor barrier. Whatever you do, do not put it on top of the insullation. OR in the middle of the insulation. It needs to be flush against the sheetrock, or dont put one in at all. No vapor barrier is probably the best way to go.

It is a vapor "barrier" so all moisture will stop and condense on the barrier causing all sorts of mold/mildew problems.

Also, be carefull of your "Can" lights. Don't put insulation on the can lights if they are not rated for it.

Most effective ways to save energy.

1. Seal any source of air draft around windows and doors.
2. Double pane windows.
3. More insulation. Attic is most important and usually the easiest.

 

[Larry the Cable Guy]

Schmoe,

That is exactly the deal we got at Lowes "Buy 20 bales and the machine is free". Did my neighbor's house at the same time so we bought three pallets (42 bales per pallet) of "Cocoon" and blew it in over the old R-13 (from 1967!) with vapor barrier.

The worst part is trying to keep the stuff out of your eyes in the white-out conditions in the attic...lift up the goggles to get a peek and the stuff gets blown into your eyes when you exhale through the mask...FUN!

Steve

 

[sprintman]

We upgraded our roof, in the walls with blow in stuff and best of all put batts under the floor. Never realised the floor was so cold in the winter now I can only wear socks or just to warm. The dogs love it too they will just drop down anywhere and sleep unlike before where it was couch or the bed. Worth every cent IMO.

 

[1sttruck]

Even though you're supposed to use a vapor barrier on the 'warm side' in for heating, some of the discussions on vapor barriers don't consider that typical exterior grade sheathing is considered a vapor barrier. You can avoid the hassle of dealing with or worrying about a vapor barrier if you use a spray in place foam insulation, or foam block and concrete construction. When we resided I also had the sheathing replaced, and we used the fiberglass batts with the vapor barrier towards the warm side. I also had foam board insulation cut and placed on top of the batts. When done the 2x4 walls had almost the same insulation value as a 2x6 with batts.

 

[Schmoe]

Is it me or does the "newer" houses have less insulation than those built in the 80's? I've driven around some new home construction areas and it seems all they do is put the cheap-o deluxe styrofoam boards up around the house and then wrap the whole house up, that's it as far as insulation goes. Nothing in-between the studs and very little in the attic. What's up with that??

 

[Winston]

quote:

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Nothing in-between the studs and very little in the attic. What's up with that??

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Maybe in Oklahoma, but here in California they often use 2x6 studs in the exterior walls in order to get the necessary R-Value.

 

[XS650]

quote:

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Originally posted by Winston:

quote:

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Nothing in-between the studs and very little in the attic. What's up with that??

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Maybe in Oklahoma, but here in California they often use 2x6 studs in the exterior walls in order to get the necessary R-Value.

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Two words.

Building codes.

That said, I think California's insulation and sealing requirements are lax compared to some states and provinces with more severe weather.