*
A brief backround: The house is 1.5 story built in 1948 and located in Mpls, MN. The attic, which is unfinished, will be converted into a master bedroom and bathroom. The plans include adding a full “shed” dormer to the backhalf of the roof, thus producing 800(plus) finished square feet from the possible 980 sq. feet existing foundation.
The ground floor ceiling/attic deck: consists of 2×12 filled with a 6″ fiberglass batts topped by 4″ of loose cellulose fibre insulation, this used to be the cold air barrier. So far I have removed the cellulose insulation in the areas where mechanicals need be accessed, approx 150 Sq.feet.
My Questions: Does the old insulation, lying beween the ground floor ceiling/2nd level bedroom floor have any usefull properties? Can it be used as a sound barrier or is it better to remove and install sound proof batts? (I would like to reduce the sound noise between floors.)
Is it worth the effort and expense to remove all the old insulation and seal cracks and holes between floors?
My contractor likes the idea of removing all the insulation, not to mention it will make his crew happy.
My insulation expert likes the idea of not removing it unless you must.
Looking for suggestions, techniques or products that might help.
DaleF
Replies
*
DaleF,
Joseph Fusco
View Image
*DaleF,I see no good reason to remove any existing insulation. The paper back, as I see it, will not cause any problems with moisture as it is not on any exterior surface. Moisture problems tend to be problems where exterior temperature changes conflict with the constant temperature of an inside living space. If your going to turn old attic space into living space, then both sides of the barrier should be a constant temperature. Therefore, very little chance of condensation (moisture problems). Also, it makes a good sound barrier. You shouldn't need anything else for a sound barrier unless you're planning to take up playing the drums.I vote for leaving the insulation.I'm sure someone here will not agree. Oh well.....Ed. Williams
*I'd still suggest digging through the batts and sealing any penetrations. I'd also recommend leaving the batt insulation in place. Built in 1948, it's probably kraft or foil-faced. While it may not be required, I'd still consider taking a utility knife and just slashing the foil or paper. Doesn't have to be extreme or fancy, just play Norman Bates for a bit.Whatever insulation that is between the joists will attenuate some sound. However, I think the biggest noise concern would be the flooring-to-joist-to-ceiling path. There are sound deadening materials that you can place between the joist top and the new attic/bedroom subfloor to reduce direct sound transmission. That would be improtant if you're installing hardwood floors. Most common are the channels that are attached to the bottoms of the floor joists with the wallboard attached to the channels. Those won't help in your case. I don't have product info on the material that goes between the subfloor and the top of the floor joist, though. I'll dig and see what I can find. Though I'm not a fan of it, well padded w2w carpet would help as well.
*
Yes! I agree with Ed!
With Mongo's refinements. Pretty good sound barrier. Why
remove what can help? You already know how (not) fun it is
to take this stuff up. Call it a healthy approach. It's a
big enough job without making it any more work.
MD
xx
*
A brief backround: The house is 1.5 story built in 1948 and located in Mpls, MN. The attic, which is unfinished, will be converted into a master bedroom and bathroom. The plans include adding a full "shed" dormer to the backhalf of the roof, thus producing 800(plus) finished square feet from the possible 980 sq. feet existing foundation.
The ground floor ceiling/attic deck: consists of 2x12 filled with a 6" fiberglass batts topped by 4" of loose cellulose fibre insulation, this used to be the cold air barrier. So far I have removed the cellulose insulation in the areas where mechanicals need be accessed, approx 150 Sq.feet.
My Questions: Does the old insulation, lying beween the ground floor ceiling/2nd level bedroom floor have any usefull properties? Can it be used as a sound barrier or is it better to remove and install sound proof batts? (I would like to reduce the sound noise between floors.)
Is it worth the effort and expense to remove all the old insulation and seal cracks and holes between floors?
My contractor likes the idea of removing all the insulation, not to mention it will make his crew happy.
My insulation expert likes the idea of not removing it unless you must.
Looking for suggestions, techniques or products that might help.
DaleF