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RE-insulating attic

testerf's picture

Hello. The majority of the 60+ year old insulation in my attic is compressed and very dusty/dirty. I doubt it has much R value.

I live in the midwest. In the summer it can get above 100 degrees with a lot of humidity. The winters drop below zero.

I would like to remove the existing faced-bats and replace with blown in fiberglass. My question is whether I need some type of vapor/air  barrier/retardant laid down on the attic-side of the ceiling before I blow in the fiberglass.

Thanks for the advice.

 

Tell us more about the (post #214040, reply #1 of 5)

Tell us more about the house.  Where in the Midwest?  Basement?  How many floors (not counting basement)?  What type of siding?  Is the siding original or has it been replaced at some point?  What kind of furnace do you have?  What sort of ventillation is there in the attic?


Of all the preposterous assumptions of humanity over humanity, nothing exceeds most of the criticisms made on the habits of the poor by the well-housed, well-warmed, and well-fed.  --Herman Melville

I live in Iowa. I have a (post #214040, reply #2 of 5)

I live in Iowa. I have a basement, a main floor and and attic. 

I have a boiler for baseboard heat.

The original siding (I'm not sure what the material is) was covered with metal siding in the early 80's (before I owned it).

This is a Sears catalog house. The attic has 3 gables.

Thanks.

Sears Catalog homes were last (post #214040, reply #3 of 5)

Sears Catalog homes were last sold in 1940, based on what I'm reading.  The siding and trim were generally all cyprus.  Later homes used a form of drywall in 4x4 sheets.

On this site you should be able to find your house plan: http://www.arts-crafts.com/archive/sears/


Of all the preposterous assumptions of humanity over humanity, nothing exceeds most of the criticisms made on the habits of the poor by the well-housed, well-warmed, and well-fed.  --Herman Melville

Hello there,  the best bang (post #214040, reply #4 of 5)

Hello there,  the best bang for the buck will most likely be to leave the batts you have in place and add blown in on top of them.  Two feet of cellulose would be my choice.  If you want a better job, then spend some time finding potential air leaks from the living space up to the attic and seal them with caulk and/or can foam from the attic side, replace the batts then proceed with the blown in.  This is the most commonly used method for our area of New England and is quite effective.  

Yeah, use cellulose, not (post #214040, reply #5 of 5)

Yeah, use cellulose, not fiberglass, and seal as many air leaks as you can first.  (With a house that old I guarantee there is a bunch.)


Of all the preposterous assumptions of humanity over humanity, nothing exceeds most of the criticisms made on the habits of the poor by the well-housed, well-warmed, and well-fed.  --Herman Melville