Home>Discussions>INSULATION & HVAC>Vented Crawl Space Cellulouse Insulation
3 posts / 0 new
Last post
Cush
Vented Crawl Space Cellulouse Insulation

I have a vented crawl space w/ dirt floor. It is approx. 8' x 21'. I called in a local insulation installer for a quote on what could be done. He suggested filling the entire void completely with blown in cellulouse insulation. I should mention that the crawl space is less than 18" high and no access.

Is it ok to place cellulouse on top of dirt w/o a vapor barrier?

The crawl space is and has been very dry since we've owned the house (2 yrs)

Thank You,

John Cushman

canuk
Re: Vented Crawl Space Cellulouse Insulation
Cush wrote:

I have a vented crawl space w/ dirt floor. It is approx. 8' x 21'. I called in a local insulation installer for a quote on what could be done. He suggested filling the entire void completely with blown in cellulouse insulation. I should mention that the crawl space is less than 18" high and no access.

Is it ok to place cellulouse on top of dirt w/o a vapor barrier?

The crawl space is and has been very dry since we've owned the house (2 yrs)

Thank You,

John Cushman

I would have to say ..... No ...... to placing the insulation directly on top of the dirt without a vapor barrier.

Even though the crawl space has been dry .... which you probably mean no standing water ..... there is moisture that wicks up through the soil into that space.

If the insulation is merely sitting on top of the dirt without a vapor barrier the moisture from the ground will wick up into the insulation which is not a good thing.

besides .... for the last couple of years that area has been dry .... what if next year things change? You may suddenly have water entering that crawl space which will leave you a soggy mess of insulation that will need to be removed and likely discarded.

Also ..... the insulation should be filling the cavities between the floor joists right to the underside of the subfloor and it's unclear if that 18 inches is from the underside of the floor to the dirt or from the joists to the dirt.

Just a thought.

Cush
Re: Vented Crawl Space Cellulouse Insulation

Thank You for your reply Canuk.

I guess there is no easy way of insulating this space without getting the shovel out.

TV Listings

Find TV listings for This Old House and Ask This Old House in your area.