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Old 01-24-2013, 02:11 PM   #1
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Join Date: Mar 2012
Location: CT
Posts: 1,906
Attic Insulation

Just completed blow-in attic insulation in my house. Specifically Owens Corning AttiCat fiberglass blow-in through home depot.

The house attic area is comprised of two parts, 1. the main original house with an average of 3-4" of original deteriorated faced batting insulation which came out to 1320 sqft of space. 2. A 2001 addition which was well insulated with aprx. 16" depth of insulation. Which was 700sqft of attic space.

My goal was to add some insulation to the addition area to seal obvious gaps in the addition's attic area, and to completely insulate the original attic space of 1320sqft to bring the rating to R60 value. I wanted to use blow-in for the ease of application and I also wanted it to be fiberglass to prohibit mold growth (which a paper insulation option would allow if moisture intrusion).

Prep. Work
1. Both bathroom fans did not vent to the outside, amazing right? I had to buy hoses, clamps, and exterior vent caps for each, & a 4" hole saw for handdrill to bring the hoses outside.
2. Recessed lighting, although all of the recessed lighting in the house was rated as self insulating, I could still see gaps of light down into the rooms below. I purchased heat rated domes at $15.00/ piece for 11 lights to cover each light. They are oblong and I utilized the longer side to fit secured between the ceiling joists.
3. Bathroom fans, microwave exhaust fan, electrical boxes. Basically everything that is electrical or generates its own heat needs a 3" barrier between it and your insulation. For this I purchased a roll of heat barrier (not cheap) but it allowed me to cut to size and utilize the ceiling joists again to create a "box" around these items and cut around hoses/wiring to accommodate the larger size than that of the recessed lighting boxes.
4. attic ladder. For most houses, there is a ladder for the attic that is the jacob's ladder style that folds... not my house, it is the one piece and extends into the attic. Essentially I build a "coffin" around it out of cheap 1"x3"x8' poplar for the frame, 1/4" ply to face it on the inside, then a roof out of the rigid foam doubled up and held together with 8" thru bolts secured to furring strips. the "coffin" was 2.5' wide by 12' long, and the rigid foam roof can simply be pushed up and to the side if electrical maintainance is needed. I also used unfaced batts to insulate the frame of this box and simply stapled it to the poplar frame.
5. Eve vent insulating, I installed roof rafter channel vents between each set of rafters to the eve vent area. the eve vent holes were spaced about 4' on center but I did not want any blow in insulation to enter the eve area space that spans the length of the house, so I used faced insulation cut into 10" wide strips and pushed it into the space between each roof rafter and abutting the underside of the channel vents, to block off the space where the blow-in insulation could enter the eve area.

Insulation time
This was by far the easiest part. From the Depot in store purchase only, I got atticcat blow-in and needed aprx. 34 bags by estimate of sqft/R60 rating based on how much insulation I already had. You get a free rental of the blow-in unit with purchase of 10 bails of this product. With myself in the attic, and a friend loading the machine outside, I was able to insulate about 1500 sqft to min. 20" depth in 3.5 hours. You get the unit that chews up half a bail at a time & 100' of hose, which shoots it out of the business end about 10' meaning you won't have to squeeze into the tight spots.

So, the majority of my time was spent on prep work as listed above.

Total cost of everything to install was $1700 including beer.

HD quoted me at $3700 for them to install it at R60 rating and do everything I listed above, minus the beer. Overall, I am very pleased with how it turned out, saved a lot of $ by doing it myself (with volunteer friends) and will save even more in my oil bill for years to come. Also, the home insulation 10% tax credit (at least for CT was extended to 2013)
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