Hi there, I just buy a house and I need some help, the house was
constructed in 1986 it's in Quebec, Canada, so we do have pretty cold
and warm climate.
My basement is directly on the slab, all the wall in the basement are
finish in sheetrock, the lower part of the wall doesn't seen to be
insulated but the upper part is, the lower part (I have look by a little
hole in the wall) seen to have a really dark paint on it that is on the
concrete, I think you call that tar in english? I heard that the bottom
of the wall wasn't insulated to let some heat go to the ground around
the foundation so that it doesn't froze? Is that the way to go, should I
put some isolation where it doesn't have?
My other question is for my floor, since it's on the slab, I want to put
a good wood floor on it, I heard about bad odor in basement and bad
stuff, everywhere I look they talk about a wood floor of 2 x 4 with
plywood and then the floor, as any of you have try other solution that
will not make odor because of wood being atacked by water ...
Have you try this solution?
It's a plastic with some space in it so that air can circulate so it can
fight again water, what do you think of that? Anybody did use this system?
Thank you for your answer.
Usually they only insulate to the point just below where the soil is likely
to freeze. Below that level, the soil never freezes, so they don't insulate.
However, the soil is still cold, so it makes sense to insulate.
I'd recommend insulating all the way to the floor. It won't make a big
difference in energy savings, but it will be warmer inside.
I haven't used it myself, but I've seen it used and it's highly recommended.
There are several companies that make such a waterproof underfloor membrane
now and I'd use it. A friend just bought a new house and I'm recommending
she use this sort of thing, along with a bit of EPS insulation, to create
a warm, dry basement floor.
Thanks a lot Michael. SO I guest the they don't isolate until floor is
more for a saving from the constructor then a technical thing.
EPS insulation how they will use it with the menbrane, I look and you
seen to put plywood directly on top of the membrane.
Michael Daly wrote:
One of the other vendors of this dimpled membrane subfloor material
suggests using the following sequence from the concrete up:
The EPS is only one or two inches thick.
I can't find that web site now, but it's a competitor to deltafl.
another strategy I've heard of is to insulate along the surface of the
ground outside the perimeter of the house. The cold theoretically has
to travel diagonally from the edge (well and through the insualtion
itself) to get that deep, and it helps the ground around the house
stay warmer. (I think this method is used more to preven frost heave
on more shallow footers, but it would help to keep the basement warmer
As far as the musty basment is concerned, you can run a dehumidifier
24/7 if you have moisture problems... but that get to be costly.
One method i've heard to use to determine possible moisture problems
is to duct tape plastic to the walls/floors and see if it develops
condensation on it. I think the best recommendation is:"if you are
not sure, get a professional.".
Verso l'esterno! Verso l'esterno! Deamons di ignoranza.
The question begins with whether you actually *need* to create a
sub-floor because of existing or potential water leakage/seepage in your
basement. That might be a tarry/rubber membrane on your foundation wall
indicating there has/had been some seepage issues in the past, or
someone might've just liked dark colored paint. Dunno. That's a good
thing to find out, so you should.
The other thing about using 2x4s for a subfloor is that you'll lose at
least 4 inches of head room. Here in the US in old/er houses, the
ceilings are very low with only about 6-7 feet of room between floor and
ceiling joists. Subtract just shy of 1 foot from that and you end up
with tall guests banging their heads on stuff. And no matter *what* kind
of treated wood you use, it'll rot and mold eventually. Might take 20
years to happen, but it will happen.
We just rehabbed our seepy basement using DriCore panels
(http://www.dricore.com ) -- and they're made in Canada. Here in the US
they're sold at Menard's stores. They're 2'x2' tongue and groove
chipboard panels only about 3/4" thick with pastic dimples on the bottom
that raise the subfloor up off the slab slightly, which saves pretty
much all your existing head space. Any seepage you get only comes in
contact with the plastic dimples, so not rot forever. Plus it makes the
floor about 5 degrees warmer, and your good wood flooring goes right
over it. We're really happy with them and solved a lot of challenges to
making our basement an actual living space.
If you do get these, make sure you can get the DriCore levelers should
you run into a low spot or two on the slab. The come 24 to a box and fit
right over the little dimples on the bottom of the panels.
Thanks a lot for your answer I have look around and find it to be a
great product (http://www.dricore.com ), the product as a warranty of 25
years which is more then an other equivalent product
(http://www.subflor.com /) which use the delta-fl procudt but has only a
15 years warranty.
I also did find a site where they did they installation of the dricore
It will surely the product I will use.
Warranty issues aside, the only reason I like the continuous membrane
more than the dricore is the fact that it's continuous. With the
dricore, you have a tiny gap every two feet.
The dricore will be easier to install, since it's like laying tile.
However, adding insulation is trickier.
If you use a carpet with generous, good quality underpadding, you'll
get some insulation.
It's probably best to find out whether you have a moisture problem to
One way is to tape down a 2' square sheet of heavy clear plastic down
on the concrete (tape all edges down), and see if you get condensation
under it over the next couple of days or weeks.
That's what we did, and the heavy underpadding made a huge difference.
Only if you have a real moisture problem do you need to consider a flooring
membrane of some kind.
Chris Lewis, Una confibula non set est
It's not just anyone who gets a Starship Cruiser class named after them.
On 12-Feb-2004, firstname.lastname@example.org (Chris Lewis) wrote:
If it's new construction, you may have to wait awhile to find out. Putting
a membrane down is insurance against later problems. I'm not talking about
major floods, of course, but minor leakage. Major leaks will need to be
All concrete will allow some moisture to pass through. Using a dimpled
membrane ensures that this moisture has some possibility of moving and
provides a bit of breathability to allow it to come into balance with the
inside air and dry out. Just putting a moisture barrier in contact doesn't
Putting wood in direct contact with bare concrete floors is a bad idea. I'm
not sure about the code on this but common practice it to put a barrier between
the wood and the concrete. I think that the dimpled membrane is much better
than just a plastic membrane as I see commonly used. With the dimpled membrane
you can construct non-load bearing partitions over the subfloor and have a
continuous air/moisture flow underneath.
It may not be the cheapest option, but it looks to me like the route to
Excellent point. Rubber membrane -- or any other manner of sealing -- is
always good insurance when making basement living spaces because, well,
how many people do we see here every month with slab crack problems?
Also, Mike brings up another great point about the need for putting air
space betwen the slab and subfloor, should future moisture problems do
come up. Membranes fail, hydro cement doesn't work forever, etc. etc.
Not only does seep water need to be able to actually *move* somewhere to
go away (usually a floor drain), but air flow is also needed to hasten
evaporation of any standing moisture.
Yes and that's the way I will go, now I look around the product and as I
said they are two main product for this:
for now the big difference is the warranty, 15 years for subflor and 25
for dricore (I found somewhere on dricore site that the warranty was 10
years they change it to 25 years after some more test, that's what they
say to me after an email). Well dricore can support more stuff on it
too, better resistance to weight, no problem for a pool table.
I also fund that subflor will have a new product that they will call
subflor advance, no information yet, well the REP is suppose to send me
some information on it, the website should be updated in a couple of
days he said. I will tell you more when I will have more information.
Thanks all for your good answer.
Not so, Mike -- at least not where those "gaps" make an actual
difference. The tongue on each DriCore panel extends out 3/8" into a
3/8" groove, making it a unified, solid-panel subfloor. Likewise, the
tongues themselves are 3/16" thick -- quite solid, IMO. The tiny little
gaps (and they're not even gaps; more like miniscule joining lines)
between each panel are the cut-back parts of the panel behind and over
the tongues, and they make no difference for anything.
Carpet with underpadding? Nice insulator, but sucks up seepage like a
sponge and grows mold when wet like the dickens.
I meant gaps in the plastic layer on the bottom. Since there is no way to
seal the plastic bits, in a worst case scenario, standing water could seep
up through the teensy gap and wet the ply part of the panel and damage the
With the continuous dimpled membrane, there are no gaps in the plastic over
the length and, when installed, you overlap the width and seal with a
caulk. You can do this easily, since the membrane is not attached to the
subfloor prior to installation like the dricore is.
This may be a minor issue.
But I meant - over the dricore or other membrane - should be dry in that
Aye, this is true, Mike. There is a tiny border on the underside not
covered by the plastic. And there's just under a half-inch of space
allowed by those underside dimples, so DriCore panels are good for
people with relatively manageable and minor seasonal seepage that heads
straight for the floor drains (but should be attacked with a sealant of
some sort anyway), not continually awful unchecked seepage or flooding.
Great insulating subfloor, tho.
I live in a 55 year old concrete block cape cod in Ottawa, Canada. Same
Francis for sure, I recently finished the lower level. The old concrete
floor was dry enough
but unlevel in some places place. I wanted to save on headroom, and I like
the idea that the dimpled
flooring would provide an insulation layer. Also that any minor moisture
under the floor would possibly evaporate or make its way to a drain. I used
Floor dimpled product, then 3/4 inch OSB, a fibre matt and then a IKEA birch
the glued variety, which I got very cheap. I also installed a small gas
fireplace and large
capacity Humidex machine, which uses a low currrent fan to push damp moist
of the basement. The lower level (we don't call it a basement any more !)
great, no musty odours, floor is warm. Its like upstairs space.
I have seen the drilock squares and the only advantage, it seems to me,
would be that they might
be a bit easier to install. They cost twice as much. I dont think that I
would worry about the
differences in warranty - its inert.
I agree with those who stated that the first issue is to ensure that you do
not have moisture issues.
If you do, none of this is going to fix them.
Bonne chance Francis!
I will like to know what is your large capacity Humidex machine does it
push air under the membrane? I was thinking that the best system will be
to find a way to push air under the membrane this way some air will
circulate and help to fight against the nasty odor. It will be an even
I didn't did the plastic strip on conrecte to see if I get to much water
in, but it did smell bad in one room in the basement, the people who
were living put some carpet directly on the concrete, this place was not
well ventilate and not well heated (since this thermostat was in an
other room !!!!???) we removed the carpet and keep the door open so no
Really, fans aren't necessary to provide adequate ventilation beneath
raised subfloors. For basements (especially below-ground ones) with no
or very minor/slightly insignificant seepage problems that have
somewhere for the water to adequately drain off so it doesn't stand
still and stagnate and come into regular contact with uncoated building
materials, the air beneath the floor will move naturally enough to keep
nature in relatively proper balance. May not seem like it would without
the need for a fan to go pushing the air around for a lot of us regular
home-owning folk, but it does.
The fact that you're smelling strong musty odor tells me that you have
some rather sizeable issues that need to be dealt with before putting
down a membrane because, well, simply sticking a fan beneath a membrane
won't solve the problem because that odor has to go *somewhere* if
you're not going to be eliminating the actual source that causes or
helps carry that odor. In other words, that odor has to go *somewhere*,
and simply blowing it around with a fan just means you're going to be
doing nothing but moving it around. You'll still be smelling it. And if
you have noticeable odor, you have a noticeable moisture problem -- and
you'll still have the same problem even after you spend a whole boatload
of money to refinish the basement. Which will mean you'll certainly end
up having to rip out everything you've just put up sooner or later.
A dehumidifier *might* help, but it's nowhere near a proper solution.
Especially if you try using one of those dinky room dehumidifiers, which
is what a lot of cheap-ass people tend to do and think it'll do anything
Your musty smell could, in fact, be caused by mold somewhere --
especially if you're getting a good whiff of it during the winter, when
the air's really dry. A musty house is a sick house in some form or
fashion. If you've got drywall, wood studs, or -- egad -- wood paneling
on your walls, betcha dollars to donuts that it (and chances are your
foundation walls, if they've been painted -- and if I recall right,
yours have been) has mold growing on it from being continually moist
from seepage. That was the case with our basement, and I was totally
ASTOUNDED by how much mold was covering everything once we ripped down
every square inch of studding and drywall put up by the former owners.
For 6 years after we moved into this house, my wife (who's slightly
asthmatic) couldn't figure out why in daylights she was wheezing so
much, waking up with headaches, coughing, etc. Our basement didn't have
a major musty smell, but it start surfacing somewhat during the humid
dead-summer months. Since the IRS was very good to us last tax year, I
insisted on using the cash to totally re-do the basement and swear to
God, I was totally floored by the mold farm that was going on behind the
walls. The whole project took 3 months and a few thousand dollars to
complete, including waterproofing masures, but the results from tearing
out every stud and every single hunk of drywall and scrubbing the
foundation walls (I used an almost 100% bleach solution on the walls, it
was that bad) was noticed virtually immediately by my wife who pretty
much paid no mind to what I was doing in demolishing the basement.
Within 2-3 days the wheezing, headaches, and coughing disappeared
You've got water-related problems somewhere in or adjoining that room,
amigo, and you really need to solve those problems and get rid of
anything affected by it (moist studding/drywall/paneling, etc.) before
you go doing anything else to turn that level into something people are
going to be using all the time.
One other thing, Francis: Contrary to what you might think, removing the
bad carpeting and keeping the door open does not make for "no problem
anymore." You've merely addressed a symptom of the disease, not the
disease itself. What you've dne is the same as people with bad back
problems who do nothing but "solve" the problem of their bad backs,
knees, or bad whatevers, by popping pain pills for years instead of just
having an operation on their back. Their bad whatevers just continue to
get worse, and pretty soon the pills don't work anymore -- or worse,
they also end up with a bad addition to pain pills to go along with
their bad whatever.
Something made that carpet continually wet in the first place. You need
to find out what it was, where it's coming from, and have it fixed
before you do anything else.
Good point AJS, if it was smelling bad that's for a reason, I do see
juste a little mold on the bottom of the wall, it doesn't smell anything
now since we removed the carpet and like I said proper eating is kicking
in now, I do know that we have some crack in the basement and a expert
came to evaluate how much it will cost, well the old proprietary did say
that no water get in when the expert was there and the crack are really
little (and we will make theme repair), I will demolish part of this
wall for sure when the weather will be a little more hot to see whats is
behind it. Do the crack go side by side and do we have moist on back of
the wall, I do have an air exchanger in that room who get cold air in
and does drop a little bite of water in a can, maybe that was the cause,
I don't know will have to see. We have the house for 2 month no smell
since the bad carpet was removed, but it is really dry, around 30 -35 %
of humidity. I wonder how it look in summer ...
Thanks a lot again to all.
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