On Thursday, March 20, 2014 7:18:49 PM UTC-5, wrote:
Hi,

I've recently bought a 1930's house with a whole house fan that discharges directly into my attic. The attic has gable vents, so plenty of discharge space is available. The attic floor joists are 2x6's and the fiberglass insulation is ancient... it's matted down to about 2" high. I'd like to replace the insulation. It's covered in a heavy layer of dust, probably most of which was deposited over the years by the whole house fan.



Is it ok to replace the fiberglass insulation and just let the dust settle on it over time? I have little interest in spending money to cover the attic floor with plywood or OSB just to keep the fiberglass relatively dust free. Should I worry about this sort of thing?



All comments appreciated.

Regards,

Theodore

T...I found heaps of info on this very situation on "This Ole House" on YouTube recently. I believe you will be able to sort it all out when you get more info. There is just too much to tell you in this way, but they go up into the attic and show you the "what" and "why" and I personally felt rather well informed after watching (I looked at several different ones).
For instances, there is some discussion on the age and safety of the older fiberglass...and putting sheet fiberglass (thick) (with a moisture barrier) perpendicular to the joist when one already has blown-in cellulose, etc... But Oren may be right! The simplest way is often the best.
Some pre-airconditioned houses were cleverly built with higher than eight foot ceilings--like ten to twelve feet instead--and windows were heavily draped (think -the velvet of the old West or deep South movies) to keep the heat outside. But...if the inside does not cool down at night when it is extra hot, then you may need to use some fans in the rooms you use often. They make one feel cooler without lowering the actual temperature, use a small amount of energy to run, and the sound can be a really pleasant white noise that will help you sleep peacefully.