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Old 07-03-2010, 09:43 AM  
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Default roof rafters insulation or not??

Question(s): Is this suggestion a good one? Does having insulation in the roof rafters help? Would I be wasting my time pulling out the R11 & placing it on the attic floor?

It was suggested by a roof installer to remove the R11 insulation that is installed in my roof rafters (not floor) of my attic and add it to the existing insulation in the floor of my attic for better insulation of the house.

They stated that all the insulation in my rafters does is "cook the shingles". There are a good number of the insulation "strips" falling out of the rafters and being held in place. I have vents on both ends of the peak & 2 within the roof itself. I have pineboard under the shingles and I will need to replace the roof on my house in the next couple years.

My primary purpose of my attic is for storage and my furnace.

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Old 07-03-2010, 10:23 AM  
Daryl in Nanoose
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I agree that more insulation in your attic floor is better, blown in is even better and you should have at least 10" if your updating
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Old 07-05-2010, 10:10 PM  
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Default roof rafters insulation or not??

I did a 1000 sq. feet addition to my house about 4 years ago. Throughout the addition we used expandable polyurethane insulation. In the walls and the roof. For the addition we used the closed cell application and for the attic roof of the existing we used open cell. Now keep in mind the open cell expands about 8x where the closed cell expands about 3x. Both have excellent insulating properties. I was extremely surprised to find all ventilation was cut off by this insulation, however I was told that the insulation is pretty much useless if there is a void in it. Now the initial cost of the insulation was about 4x more expensive but after doing the calculations I figured it would take about 8 years for the insulation to pay for itself. The savings were immediate in the electric bill where during the peak summer months it normally ran about $225 for a 1500 square foot house it was now down to about $125 (the highest) for a 2500 sq. foot house. I would totally look into this insulation if you are looking to make an investment in your home or wanting to save money on your electric bill. I might also add that you do get a tax credit for using this insulation. Not a big one but everything helps.

Oh the attic never gets above about 85 degrees even in the dead heat of summer here in south Louisiana. Which also is good working conditions for the evaporator coils.

If I can be of any help just let me know.
Big Jude
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