I am in the process of finishing our basement. Our home is 2 years old
with poured basement walls. We have started to put up 2x4 framing
against the walls, and planned to insulate with faced R-13 fiberglass
insulation, and put up 1/2 drywall. Recently a friend suggested that
we put plastic sheeting between the framing and the concrete walls to
keep out moisture, and use unfaced insulation.
My question is, what is the best way to do this? Our basement has had
a very small amount mildew appear in the summer, in the past. And, if
the plastic sheeting is put up between the concrete and the framing,
should the insulation used be faced or unfaced?
I am also interested in insulating the concrete floor as well, and am
open to suggestions on what to use for that as well.
Thank you very much for all feedback and suggestions!
IIRC, you don't see moisture migrating through poured concrete unless there are
substantial cracks. Any mildew would be caused by moisture in the warm air
condensing on the colder concrete. That's why the moisture barrier should be
facing the source of moisture, which is usually the living area.
Poly sheeting is cheap though and can't hurt. When I framed in a basement in a
home a number of years ago, I put poly sheeting between the studs and the
concrete, and then used standard faced insulation with the moisture barrier
facing the living area. You wouldn't want unfaced insulation as that would let
moisture condense in between the studs.
Heat rises and the earth is a pretty good insulator, so insulating the floor
won't be a money saver or comfort improver. A good pad and carpet is all you
really need. That said...
Headroom is usually an issue in basements, so you typically can't put joists on
the concrete.You could do this: Seal the floor with a two part epoxy paint. Use
1x2 lathing strips spaced at two foot intervals with sheet styro in between.
Particle board flooring over the lot.
Hmm.... rule of thumb is that 10" of concrete is R1... though the
floor will be below the frost line (poster did not indicate his
climate), a substantial amount of heat/comfort will be lost to the
floor. (Here in New England, it is required to have insulation on the
basement ceiling, to reduce heat loss on the first floor).
Personally, I would never use particle board flooring, and
especially below grade. I do like the lathing strips/sheet styro
method; I use PT lathing, and a heavy grade poly sheeting under all,
instead of the epoxy paint.
Tape some plastic or foil onto the wall and another onto the floor.
Come back the next day and see if you have moisture forming on the side
toward the wall or toward the room. Come back and let us know.
On 28 Dec 2004 19:13:49 -0800, firstname.lastname@example.org wrote:
While I am not a builder I did have our basement finished a few years
ago. What the builder did was to "seal" ALL the concrete with Dry-Lok
clear sealer then covered the walls with thick plastic sheeting. The
wall studs were then attached to the walls with special fasteners
"shot" out of a gun.
We've had ZERO problems with moisture with this method.
But the fasteners have now punctured both the waterproof layer created
by the application of Dry-Lok and the plastic sheeting.
Our basement walls had already been painted or treated with Dry-Lok or
something of that type (I have no means of knowing what), so I used
heavy plastic sheeting between the wall and the studs, but I anchored
the new bottom and top plates only to the floor and the joists and did
not fasten the studs to the walls.
On 12/29/04 09:42 pm Bob_M tossed the following ingredients into the
ever-growing pot of cybersoup:
Ask your local building inspector -- if it isn't done to code and he
finds out about it, he may make you do it over again. Best to ask first!
I've always found those guys friendly and helpful, if you go at it with the
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