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I need to add more insulation to my attic. Currently the only part of my attic that has insulation is the floor which is blown in insulation. My question is do I need to add more to both the floor and the roof or should I just do the floor? Thanks in advance.
 

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Just the floor. Just check the depth and there are all sorts of places that can tell you what that equates to in R-value, and what will be needed when you decide to add more.
 

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Jedi-

I reinsulated the attic in my 30 year old house about 3 years ago. My wife and I blew in the loose cellulose insulation that Home Depot sells. We added about 18" of the stuff and noticed about 3-5 degree increase in winter temperature and about 8-10 degrees in summer.

You only insulate the surface adjacent to living areas. Be sure to put attic vents and or an attic fan to circulate the air. In summer moves out the hot stale air, and in winter it keeps the exterior walls the same temperature as the outside to prevent the possibility of ice flows causing leaks. . . .

Hope my two cents help.
 

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The biggest bang for the buck

The best insulator is Poly-Iso foam. PERIOD !!!!! Lets not have anymore discussion on anyone blowing anything, unless we are talking about each other.



Spray between the Rafters NOT the Joist !!!!!

I will repeat for the slo bus members........

Spray Poly Iso foam between the rafters and save the most energy. It works even better if you use a radiant barrier before the insulation is sprayed.

We took a 7000 sf house with 6 ac units to $275 bucks a month for electric service. My wife wears a coat in our house 365 day a year.
:dustin:
 

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The best insulator is Poly-Iso foam. PERIOD !!!!! Lets not have anymore discussion on anyone blowing anything, unless we are talking about each other.



Spray between the Rafters NOT the Joist !!!!!

I will repeat for the slo bus members........

Spray Poly Iso foam between the rafters and save the most energy. It works even better if you use a radiant barrier before the insulation is sprayed.

We took a 7000 sf house with 6 ac units to $275 bucks a month for electric service. My wife wears a coat in our house 365 day a year.
:dustin:
Yes, that would be more effective, but pretty much only if you wanted to remove all of the existing blown insulation and start over. If the OP just wants to add to what is existing, he doesn't need to worry about the rafters if there is already insulation in the joists.
 

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yeah the price for any of the of the spray foam variations either closed or open cell has dropped enough for the average home owner to be able to afford to do yet, the blown in yields the highest gains per ease and price for the average person. You can buy 2-400 bucks of blow in insulation and they will let you use the machine for free vs. paying a spray foam contractor a crazy amount to do it.

I have done both and yes I am fully aware how well the closed and open cell spray foams perform and blow cellulose out of the water but my response is to his statements.

also make sure that you install any draft stops that you may need as in roof height transitions and so on. And poly seal foam in the cans, now is the time to go up there and spray foam all of your ceiling penetrations, wire, and plumbing penetrations and so on through the 2 x 4's for the walls.

Fyi, the plastic throw away bowls (think cheap paper and plastic plates), fit perfectly over the electrical boxes (where your lights and fans screw into and wire up to) to be able to polyseal foam them for air leaks.

Recessed cans are your worst enemy, put your hand under one during the summer and you will feel the exhaust billowing out like a furnace. The ones that are supposedly sealed are not hardly sealed at all.

Good luck and don't get the itchy kind as it sucks to work with.
 

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Be sure they have eave dams up to keep the blow insulation from plugging your venting...otherwise you'll get the pleasure I just had--tunneling through blown insulation to clear the vents and then install them. :)
 

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Oh yeah I forgot to post that, and an easy way to blow the insulation back in from the eaves is to use a leaf blower around the soffit vents, of course this works better when you have the continuous vent all the way around.
 

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No such luck for me... they evidently thought it was a good idea to stuff batting in there first. like full rolls. :) hence the attic shovelling, garden rake / put up eave dams fun. Soon I'll add more insulation too.
 
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