Blown in attic insulation

[huskres]

I have an old house built in the 40's with very little insulation. Thinking about buying a bunch of the bags from lowes or home depot and blowing them in. I will cover my furnace before I blow it in and remove the cover once im done and keep access to it so it can be serviced. What should I do about my recess lights though? Just blow over the top of them or something else? Think I should mark where the junction boxes for all the electrical will be buried also?

Has anyone done this before and noticed a difference in ac run time?

 

[Shoot Summ]

I plan to have this done eventually, once I am done remodeling. Everyone indicates it will make a big difference. Your recessed lights will need baffles unless they are rated IC.

 

[doctorjj]

Shoot Summ is correct. You'll have to check and see if they are IC (insulation contact) rated. If not, I would suggest replacing them with airtight IC rated fixtures. They aren't that pricey and you will recoup that investment fairly quickly.

 

[Jwryan84]

They also make styrofoam boxes to go over them. Blow fiber it wont settle as much as paper will. I did it about 3-4 years ago in my old house and am about to do it in my new one. And wear a mask. Make sure you buy enough to get the blower rental for free. Wish you were closer we could help each other out. Last time I did it we did 4 houses in a day.

 

[Artic-Z]

i added 30 bags of blow in recycled cellulose stuff from lowes when they had it on special for like 7$ a bag. its blows in very easily it also seems very air tight but a little dusty. i blew in almost an additional 18-20" over 1300 sq ft. after about 6 months it seems to have settled to like 12" wish i'd have done more bags, surely it'd have helped even more. my AC seems to stay off longer and i've seen some pretty good savings specially in the winter time. hard to keep our AC in with as much as me and my wife and the dogs go in an out. also we just bought a lot better thermostat that should be saving us quite a bit of money.

normal house temps while were home are set to 72, while away 84 takes about 30 minutes to cool down.

 

[doctorjj]

I'd stick with cellulose. Oak Ridge labs has done quite a bit of research and have shown that blown in fiberglass doesn't perform as well as the calculations would indicate and performs very poorly when the temps are really cold. Either cellulose alone or a couple of inches of cellulose capped over the blown in fiberglass is the best. As for the styrofoam boxes, they work or you can make your own from some rigid foam. I'd go with LED's in your cans if you do that to minimize the heat build up.

 

[justanotherpatriot]

I put about 13 inches of the fiberglass comfort therm from lowes in my attic before the big blizzard (for a total of 16-18") I heated my whole house approx 1700 SF single story that winter with an earth stove and about a rick and a half of hardwood. Didnt even turn on the furnace till the temperature fluxuated enough it was more hassle than worth it to keep a good bed of coals going. We went from $300 plus a month with gas & elect. to $80 -100 per mo. By the way you can always buy enough to get the free rental and return the extra if you dont need it.

 

[O4L]

You picked a very bad time of the year to be working in the attic.

Take breaks after being in the attic for 15 minutes, or you will regret it. Better yet, wait until it cools down.

I used to have an insulation business, 30+ years ago, and a hot attic in the summertime can be very dangerous.

 

[pinkhamr]

Excellent point on summertime installation ...... we did it back in 1982 ...... 16" and more bags then I can count ...... Must have had 2 gallons of iced tea and water that day! Heat Stroke is not good for you ......

 

[Sanjuro82]

I had cellulose blown over the winter, and I'm so glad that I did. My bills are about quite a bit lower. 2011 May and June I paid $90.42 and $93.50. This May I paid $38.59 and June so far is at $56.48. They blew in 15 inches over the original fiberglass (probably only a couple of inches of loft left).