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Crawl space insulation

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Jan 13, 2014, 08:15 PM
Crawl space insulation
I have a house that has a vented crawl space.
It ranges from 5 feet in height down to two
feet. Dirt floor and stays dry. There is a gas
furnace located in the crawl space and it keeps
the area fairly warm. The wood floors above
along the perimeter must have been cold in the winter
and the previous owner insulated the crawl space ceiling
along the perimeter. Should I remove the insulation or
keep it ? The crawl space ceilings look find but I have
not seen the done in the Memphis area before.
Jan 13, 2014, 09:16 PM
Since it's vented there are some things you should do:

1. Add a vapor barrier. This is most important and fairly easy and inexpensive. Roll out 4mil or 6mil poly and cover 100% of the exposed dirt.

2. Insulate all of the subfloor above. Even though you do have a heat source in the crawl space, the open vents can negate that - especially when it gets very cold. Install R19 faced insulation in-between the joists with the paper facing up towards the living space. This too is fairly inexpensive and easy to do, just messy.

Jan 13, 2014, 10:13 PM
This is exactly what I'd like to do. I would like to insulate my floors and also have just a crawlspace with dirt floor. But my sub-floors don't have floor joists to attach insulation to. My house is pier and beam construction with the beams spaced 5 feet apart. Is there a product that comes in wider sizes or how else can I attach the insulation?
Jan 13, 2014, 10:51 PM
You can install slats across the underside of the beam "joists' that you do have. The slats can be 1/4" x 1-1/2" wood slats or even vinyl webbing.

If you have a table saw, you can rip the slats out of 2x stock fairly cheaply. The slats will need to be about 2' apart to support the insulation. Once the slats are in place, just weave the insulation up on top of it. Or, you can hold the insulation in place with some staples into the subfloor above, then install the slats to hold the insulation over time.

Jan 14, 2014, 12:03 AM
Thanks, Jaybee! My crawlspace is tight, about 18 inches to at most 30 inches (but the majority is 18 inches high), so I'm wondering how difficult it will be to install the slats or webbing throughout the entire 1200 sq.ft. Do you think that a DIY'er can tackle this work? Also, what's vinyl webbing?
Jan 14, 2014, 06:36 AM
Not really sure what Jaybee was referring to but you can buy the rolls of 2" plastic webbing similar to what they use to repair or replace the older folding lawn chairs. Use a staple gun to install.
Jan 14, 2014, 08:21 AM
Yup - red's got it right.

18" is tight. Installing the insulation itself is not too difficult and is certainly a DIY type project. If it were me, I think I'd be hiring a couple of skinny high schoolers to do most of the install.