crawlspace insulation

[christophergraber]

i'm wondering what type of insulation i should use in my crawlspace and how i should install it? approx how much should it cost (small house, around 800 sq feet)

my house is on somewhat of a hillside, so part of the crawlspace is about 6' tall and the other side is about 2.5' tall. in the middle are piers and columns. the 'ceiling' of the crawlspace is just big beams running from one end to another, with floorboards above and the actual hardwood floors above that... there are some pipes and electric lines here and there as well. the floor of the crawlspace is dirt.

is there anything special to consider, or can i just go to home depot, buy some random insulation rolls of a medium rating and staple gun them up?

please respond to the group and to my email if possible

[Tony Hwang]

Hi, Sounds like your place is similar to my cabin built on wood piles. My crawl space is enough for me to sit up and do things. There we have hot water tank, furnace, well water pressure tank. I snug fit R20 fiberglass batts between joist, around walls are covered with R12 same material and vapor barrier. Even in cold winter down there it's quite comfy having two hot air outlet from furnace. Even the size of house is almost same as yours. I am in Alberta where winter is pretty cold. BTW, my wall studs are 2X6. Tony

[George E. Cawthon]

Before you do anything else, fix the dirt floor like it suppose to be. Buy some 6 mil plastic and cover the dirt; over lap seams about 3 feet, and lap the plastic up about 12 inches around the piers and the walls. Do not tape any of the seams as you want an open pathway for water to leave in case water gets into the crawl space.

You have two choices for insulation--insulate the floor or insulate the walls. A tight crawlspace with insulated walls is suppose to be more effective than insulating the floor. If you choose to insulate the walls, make the plastic on the dirt go up the wall 1-2 feet and bring the insulation down the wall and out about 18 inches over the dirt (plastic between dirt and insulation). 'Course if the crawlspace regularly floods, you will be better off if you just insulate the floor. Still need to cover the floor with plastic

[Tony Hwang]

Hi, My floor is just super dry gravel form the beginning. What is the purpose of covering it with plastic sheets? Can I lose heat thru floor? Tony

[Bob]

my crawlspace and

(small house,

crawlspace is

and the actual

electric lines

dirt.

to home depot,

staple gun them

suppose to be.

seams about 3 feet,

and the walls.

for water to

or insulate the

suppose to be more

insulate the

feet and bring

over the dirt

crawlspace

insulate the

is the

heat thru floor?

It is to prevent moisture from coming out of the ground into the crawlspace, and thereby into the structure.

Bob

[George E. Cawthon]

No, the purpose of the plastic is to keep from wicking up moisture through the dirt and causing continuous high humidity.

Not many people have gravel in the crawl space. Your house isn't built on gravel is it? Or was the gravel just added as a covering over dirt? In either case I wouldn't think covering it with plastic would do much.

[Tony Hwang]

Hi, In that case, I am OK then. No moisture problem down there. Thanks, Tony