attic insulation question

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  #1  
Old 02-06-13, 01:15 PM
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attic insulation question

my house was built in 1960. I just had my roof spray foamed this past fall. so its air sealed. My attic used to be almost the same temp as out side but now its about 8 degrees colder then what I have the heat set to even when it was 0 out. Im saving about 50% over last year. My problem is that the old batts are still there all in piles and so on. there all falling part and full of dead mice, s..., nuts and so on. It smells bad up there, but only up in the attic. there are no new mice up there so they must have been coming in from the soffits or something. Alway i was thinking of removing all of the old batts and vacum up all the stuff. Would it be a good idea, and save more money if I put new batts down say R30 with no paper on the batts? I'm just wondering if rasing my R vale would help at all.
 
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  #2  
Old 02-06-13, 01:52 PM
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So you have insulation on the floor of the attic and in the rafters of the roof?

If so, then yes, get rid of the batts.
 
  #3  
Old 02-06-13, 02:12 PM
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What is the R-value of the spray foam?

Definitely get rid of the old garbage. I don't think it will be worth the money to install new batts at the floor. You are already saving 50%. That's a big savings with just roof insulation. If it was worth the money, I don't think you want to add more insulation at the ceiling again. You should keep all the insulation at the same point in the building. If the price of energy skyrockets, adding rigid foam to the underside of the rafters would probably be the way to go to increase R-value.

Keep in mind that is you divide 1 by your R-value, that is the percentage of heat you are loosing through conduction. If you have R-19 then you have allowed about 5% of your heat to be lost through conduction. So you have blocked 95%. Go to R-30 and you have blocked 98%. That's only 3 more percentage points. You also have 100% air sealed your attic and that counts for a lot too.
 
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Old 02-06-13, 05:39 PM
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Sorry for got to put that data down. the spray foam is r-23 sprayed on the roof. so all you see is foam up there. you do not see the rafters anymore.

Yes they left the old r-19 batts on the attic floor.

[ATTACH=CONFIG]8920[/ATTACH]
this is what it looks like. somebody put newer batts ontop of the old stuff in this area.

Yep I know and the old stuff still has the paper on it . Well what's left of the paper.

Ok, ya I think the spray foam is like 95% I think they hold me.
ok thanks for the input. ill just clean it up the old batts then.
 
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Old 02-06-13, 08:40 PM
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Yep, insulation in one place only and the stuff in the roof kicks the crap out of that fiberglass, make it gone.
 
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