Basement finishing suggestions?
 

Hello:

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!

--
Chris

In article .com,
wrote:

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.

Much depends on what climate you are in. Are you in Tucson, where it
is extremely hot and dry, or in Houston, where it is extremely hot and
wet, or in Minnesota? Is the humidity in the basement is from
groundwater infiltration? Or is it from warm, moist summer air,
coming into the very cold basement, and condensing on the cold walls?

Are your walls formed and poured concrete (pretty little moisture
transmission, unless there are cracks), or concrete blocks that have
been grouted with concrete (much more)?

Please consult a local expert who knows the local situation, in
particular with groundwater issues.

I'll make just one general comment. Consider doing this: Instead of
putting a vapor barrier (like 10 mil polyethylene, a.k.a. visqueen),
between the stud wall and the concrete wall, put a 1" or so layer of
foam insulation in. Some foam products can act as a vapor barrier,
and they have excellent R-values. And you can get a completely solid
layer of foam against the wall, with no penetrations at all (no studs
in contact with potentially moist exterior wall), which improves
insulation considerable (remember, wood is R-1 per inch, so the 2x4
studs are R-3.5, which is in parallel with the R-13 of the fiber
insulation between them. Also, like this the studs don't come in
contact with the potentially moise exterior wall. But make sure the
foam insulation can handle exposure to moisture (not all can).

--
The address in the header is invalid for obvious reasons. Please
reconstruct the address from the information below (look for _).
Ralph Becker-Szendy

Clark W. Griswold, Jr. wrote:
wrote:



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...

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).


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.

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.

I live in Michigan, where we have humid summers up to 85-90 degrees F
and somewhat dry winters down to 0-10 degrees F.

The mildew that we have seen only occurs in the summer, where the warm
humid air enters the cool basement. We do not have any infiltration of
ground water through the walls or floor, and the only cracks (1/8 inch)
in the wall are where two seams are in the very middle of two of the
walls. The outside of the walls were tarred when the house was built.

So with that information, will putting in the plastic sheeting between
the concrete and the framing provide any advantage for us?? And if so
should I also be using faced insulation then??

Thank you very much again for your help!...
--
Chris

wrote:
In article .com,
wrote:

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.

Much depends on what climate you are in. Are you in Tucson, where it
is extremely hot and dry, or in Houston, where it is extremely hot
and
wet, or in Minnesota? Is the humidity in the basement is from
groundwater infiltration? Or is it from warm, moist summer air,
coming into the very cold basement, and condensing on the cold walls?

Are your walls formed and poured concrete (pretty little moisture
transmission, unless there are cracks), or concrete blocks that have
been grouted with concrete (much more)?

Please consult a local expert who knows the local situation, in
particular with groundwater issues.

I'll make just one general comment. Consider doing this: Instead of
putting a vapor barrier (like 10 mil polyethylene, a.k.a. visqueen),
between the stud wall and the concrete wall, put a 1" or so layer of
foam insulation in. Some foam products can act as a vapor barrier,
and they have excellent R-values. And you can get a completely solid
layer of foam against the wall, with no penetrations at all (no studs
in contact with potentially moist exterior wall), which improves
insulation considerable (remember, wood is R-1 per inch, so the 2x4
studs are R-3.5, which is in parallel with the R-13 of the fiber
insulation between them. Also, like this the studs don't come in
contact with the potentially moise exterior wall. But make sure the
foam insulation can handle exposure to moisture (not all can).

--
The address in the header is invalid for obvious reasons. Please
reconstruct the address from the information below (look for _).
Ralph Becker-Szendy

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
right attitude.

Dave


wrote in message
oups.com...
Hello:

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!

--
Chris