? Blown In Cellulose or Fiberglass Insulation

13 years ago

I need to insulate my house built in 1930's. There is no insulation in the walls and 30 yrs ago, fiberglass batts were installed in the floor of the attic. Not all the bays were insulated and right now I can't tell which one's were not. Of the ones I can check, it looks like the fiberglass batts have settled, there is a space before reaching the top of the bay and they don't seem to fit as snuggly as they did when they were first installed. It has been suggested that I use fiberglass blown in insulation over cellulose because it won't settle. Are there any other benefits to blown in fiberglass over cellulose? I am told the R value is the same for both fiberglass and cellulose. Is that correct? I have some info of a certain company that says blown in cellulose insulation has a higher R value than fiberglass. Talk about confusion!!! I have also heard that the boric acid in the cellulose insul eventually breaks down and becomes ineffective. Also the floor boards in the attic have spaces and cracks between them so I am concerned re blowing in any type of insulation and having the fibers wind up in the air that we breath. Would the use of tyvek underneath the floor boards be at all helpful in preventing this? Heating bills are HIGH. Would appreciate any imput. Thanks

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