Doing a full gut - leave attic cellulose insulation or replace?

7 Replies

I'm fully gutting a single family house. I have the lathe and plaster out of the finished attic and there is a ton of cellulose insulation behind the walls. Should I leave it in place or dispose of it and replace it? The house has a lot of mold so I am a little worried about moisture in the existing insulation.

Do you know where the moisture is coming from? If there isn't any in the insulation, and moisture isn't coming in there, it's probably fine. 

from what I've learned with other properties.. if you're already doing a gut.. just get rid of it and put in brand new.  Get a better R value perhaps. Or maybe in pulling it you find another issue you can easily fix.  I would toss it all and put in all brand new insulation.  Also a selling point down the road that "all insulation is new" in the property (you should advertise this as well)

@Steve Emling , replace is what I would do. Cellulose is basically paper they mix with chemicals to give it a fire retardant quality. It can retain moisture and if you had mold in this house it’s an easy decision. Those spores spread to anywhere and everywhere.

If it’s a flip house. When you go to sell, think about inspections. They always note insufficient amount of insulation. Then give the thickness it should be by code. You’ll most likely need to blow more in anyway.

If it’s a buy and hold. Imagine tenants complaining about heating bills and how the upstairs is cold. A happy tenant is a quite tenant. So I always over insulate everything. So what I spend an extra 1000.00 on insulation. It makes both parties happy. Along with when I sell it in ten years the fiberglass will still be good to go.

Good Luck

Originally posted by @Steve Emling :

I'm fully gutting a single family house. I have the lathe and plaster out of the finished attic and there is a ton of cellulose insulation behind the walls. Should I leave it in place or dispose of it and replace it? The house has a lot of mold so I am a little worried about moisture in the existing insulation.

 Steve, what's this cellulose insulation look like? We live in the same cabbage patch and our patch has a lot of asbestos.in it. Are you sure this cellulose isn't vermiculite?

New to BP, but I have 20 years exp in building and 25+ in managing RE facilities  I have first hand exp in mitigating mold as well as DEP & EPA training.

MOLD is a 4 letter word, it is the new asbestos for insurance companies.  Some legal analyst say it is worse.

Mold likes moisture + organic food and prefers similar temps to us humans.  It's spore float around year round.  Practically in every breath we take.  It can even grow on moist metal surfaces with air passing over it.  Exmple AC duct work.

The best way to control mold is to control moisture.  Mold is linked to respiratory issues in young, old and immune compromised and suspected in more.  Unless you live like Howard Hughes, you can only really control the moisture part of the equation.

IMO

You need to first find the water or moisture source and fix it.  Your roof keeps your investment safe and dry.  Do not skimp on roofing work.  Just slapping on roof tar in the area is a recipe for future disaster.

As for anything suspicious, (unless you are trained and test it, you do not 100% know it is mold), mold procedures are; remove it, remediate and encapsulate.  AFTER the moisture source is resolved.

So simply, if you suspect anything has mold, get rid of it.  Fix the source of moisture!  Dry out the moist areas.  Best use a commercial drier, available at tool rental stores, then seal it.

Sounds like a lot of time and $, but the liability is major.

When installing new cellulose make sure it has mold inhibitor in it.  Most now do.

There is a lot more specifics if you are interested.  

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