To seal/insulate a crawlspace or not
#1
06-04-04, 06:52 AM
To seal/insulate a crawlspace or not
I am in the process of purchasing a new home and just had the inspection done.
The inspector suggest 6-10 mil plastic sheeting to cover the crawlspace ground (sand) to help prevent moisture and also stated I shoudl treat the crawl space like a basement. He said to seal the vents, put the plastic down, insulate the floor joists and put a dehumidifier in the crawl space. He said current practices (venting the crawl space) is outdated and has not caught up with the latest scientific based information. I am going to put the plasitc down and also insulate the joist area but I would like to hear the pros and cons on sealing the vents and treating the crawlspace like a basement
Thanks
Site
The inspector suggest 6-10 mil plastic sheeting to cover the crawlspace ground (sand) to help prevent moisture and also stated I shoudl treat the crawl space like a basement. He said to seal the vents, put the plastic down, insulate the floor joists and put a dehumidifier in the crawl space. He said current practices (venting the crawl space) is outdated and has not caught up with the latest scientific based information. I am going to put the plasitc down and also insulate the joist area but I would like to hear the pros and cons on sealing the vents and treating the crawlspace like a basement
Thanks
Site
#2
06-06-04, 10:23 AM
Im with him most of the way. But out date no way. Been doing it that way from back in the 60's. No vents at all 6 mil poly on the ground. Over lap 2' and up the walls 1' .Tape all seams. 2" or 3" polystyrene up the walls to the joist. Put a R19 insulation in the joist space there on top of the sill plate all around the home . No insulation in the joist.
When the duct work is down there .We put two register outlets and one in the return. If not have a small dehunidifier you can turn on down there. Any of the gov www. will tell you the same thing. With any vents there the warm moist air will come in on the cool ground and just make everything wet.
ED
When the duct work is down there .We put two register outlets and one in the return. If not have a small dehunidifier you can turn on down there. Any of the gov www. will tell you the same thing. With any vents there the warm moist air will come in on the cool ground and just make everything wet.
ED
#3
06-06-04, 11:14 AM
Thanks Ed,
I plan on sealing up the crawlspace. The supply ducting is down there but the return ductwork is in the attic so I will put a dehumidifier down there but make sure to shut it off in the winter. Why no insulation in between the joists themselves?
Site
I plan on sealing up the crawlspace. The supply ducting is down there but the return ductwork is in the attic so I will put a dehumidifier down there but make sure to shut it off in the winter. Why no insulation in between the joists themselves?
Site
#4
06-06-04, 11:26 AM
let that small register down there open all the time . Makes for a warm floor and happy wife. The whole crawl space works as big heat sink for the home. Hope home has gutters on it and good slope away from the home on the ground. On any older homes that have had insulation in the joist.It didnt work. Insulate the walls and all around the belt board of the home on the sill plate.
ED
ED
#5
06-06-04, 11:35 AM
The house has gutters but they are clogged and drop right at the foundation. I am going to have them cleaned and extend them 4-6 feet away from the foundation which already has a good slope away from it but not good enough for a zero length run, which is what it is now.
The heat from the register will not cause problems with condensation ?
Ed.. thanks for your input
Site
The heat from the register will not cause problems with condensation ?
Ed.. thanks for your input
Site
#6
07-19-04, 05:41 AM
Ed,
We put two register outlets and one in the return
My supply ducting is in the crawlspace while the return ducting is in the attic.
Should I not worry about adding vents from the ducts and just go with a dehumidifier ?
Someone made a point to me to be concerned since there will be no air exchange which is not good. I see if I put supply and return vents down there it would exchange air but what if there are no vents, just the dehumidifier?
Thanks for all your help so far.
Site
We put two register outlets and one in the return
My supply ducting is in the crawlspace while the return ducting is in the attic.
Should I not worry about adding vents from the ducts and just go with a dehumidifier ?
Someone made a point to me to be concerned since there will be no air exchange which is not good. I see if I put supply and return vents down there it would exchange air but what if there are no vents, just the dehumidifier?
Thanks for all your help so far.
Site
Last edited by sitedrifter; 07-20-04 at 05:17 PM.
