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-   -   does old attic insulation have to be removed? (http://www.diychatroom.com/f103/does-old-attic-insulation-have-removed-134139/)

yurtgirl 02-18-2012 07:26 AM

does old attic insulation have to be removed?
 
I took a look at the insulation in my beau's attic for the first time (he's had it for 15 yrs, i've lived with him there for 5) and was shocked. :eek:
It is so old it looks like its breaking down. It's about 1 inch thick and the paper on top is all cracked and broken. We've talked about doing the blown in cellulose and will probably do it very soon. But, do we need to remove the old pink stuff first?
fwiw, the house was built in the 60s and remodeled by a previous owner in the early 80s. the beau purchased it "as is" in mid 90s. That insulation has to be at least 25 yrs old.

btw, i've searched this forum for similar posts and have seen all kinds of answers, so I thought I'd try a new post and see what I can find out.

Thanks!!!
yurtgirl

joecaption 02-18-2012 07:36 AM

Welcome
Do us all a favor and tap your name where it shows whos posting and edit your location for better info.
http://www.energystar.gov/index.cfm?...sulation_table

Open this up to see how much insulation was suppost to be up there.
If your going to add more insulation you have to make sure the soffits do not get blocked up by adding foam baffles, is there a ridge vent on the peak of the roof?
Sounds like the insulation may have been installed up side down. The paper was suppot to go toward the conditioned surface. All you should be seeing is insulation not paper on the top side.
There no reason to remove what you have just flip it over so the papers toward the ceiling and add more over it.

yurtgirl 02-18-2012 07:49 AM

thanks for the quick reply.
i guess we could flip it over but the paper is so cracked and deteriorated that it doesn't look like it would work as a barrier. It looks like it would just fall to pieces if we moved it. Should we buy something to use as a barrier?

joecaption 02-18-2012 07:57 AM

Then just remove it and add new R-30 fiberglass backed insulation.
While the insulations out hit all the light fixtures and fan boxes with spray expanding foam to stop ait leaks.

framer52 02-18-2012 09:14 AM

Instead of fiberglass batts, I would go to the local box store and buy cellulose insulation. If you buy more than 20 bags, they let you use their blowing machine for free.

The reason is that cells lets less air flow than the fiberglass. Not to mention it is less expensive......:whistling2:

Nailbags 02-18-2012 01:44 PM

Quote:

Originally Posted by yurtgirl (Post 856443)
I took a look at the insulation in my beau's attic for the first time (he's had it for 15 yrs, i've lived with him there for 5) and was shocked. :eek:
It is so old it looks like its breaking down. It's about 1 inch thick and the paper on top is all cracked and broken. We've talked about doing the blown in cellulose and will probably do it very soon. But, do we need to remove the old pink stuff first?
fwiw, the house was built in the 60s and remodeled by a previous owner in the early 80s. the beau purchased it "as is" in mid 90s. That insulation has to be at least 25 yrs old.

btw, i've searched this forum for similar posts and have seen all kinds of answers, so I thought I'd try a new post and see what I can find out.

Thanks!!!
yurtgirl

OK one inch of insulation is around R-5 you need to be at R-31 also the paper is not to be on top that can cause dry rot of the under side of the roof. you don't have to remove the old just the paper and add to it blown in is fine to do just get it up to or above R-38 and make sure you don't block the bird blocking. or it will wreck havoc on your roof.

Gary in WA 02-18-2012 11:00 PM

I'd remove and discard the f.g. and air seal as said before adding new insulation: http://www.google.com/url?sa=t&sourc...wWATQw&cad=rja

The old f.g. batts can help you find the existing air leaks effectively, thus stopping the "stack effect": http://www.finehomebuilding.com/PDF/Free/021105092.pdf

At 1.5-2# per sq.ft. the cellulose would crush the f.g. same as a small water bottle every foot apart. This would mute the f.g. and interfere with the cellulose' ability to air seal as well. Be sure your ceiling can handle the added weight load: http://www.energyguide.com/library/E...SubjectID=8375

Can foam the wiring/plumbing holes in the basement/crawl floor above as well to stop the upward replacement air drive:http://www.wag-aic.org/1999/WAG_99_baker.pdf

And, welcome to the forums!

Gary


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