After stripping the flooring to the bare concrete slab, I removed the
wood trim at the bottom of the wall. There is an irregular 1/4" gap
between the slab and foundation along the complete length of the outside
walls. Most likely, the gap is due to shrinkage over the 40 years since
the house was built.
I'm planning to install a Pergo-type laminate floor over the recommended
vinyl vapor barrier. I'll extend the barrier up the walls 1-1/2", so it
covers the gap but will be concealed by the new floor molding. Should I
fill the gap, with caulk or some other flexible material?
Many houses have a french drain for drainage where the slab meets the
walls. Though it's usually wider than 1/4", more like an inch.
Also, your construction technique here seems a bit odd, as is sounds
like your planning on putting the floor molding right up against the
foundation wall? No inside wood framing or furring stips for
sheetrock or similar?
I'm a bit confused ........ is the gap on the outside of the house or is
it the gap on the inside, between drywall and the slab?
It is normal for there to be a gap on inside at the bottom of drywall;
it is the reason for being for baseboards. If drywall
went to the floor, it would not allow for expansion/contraction or settling.
When we repainted and tiled our LR/DR, I put color-matched caulk along
the baseboards all around. I was thinking,
at the time I did it, that wet mopping might get under the baseboard a
little bit, get absorbed by bare wood and cause
the paint to crack or peel. It was only a few months later that our
washer hose broke and flooded kitchen and DR.
Caulking the baseboard helped contain the flood :o)
We have a neighbor who had a brand new Pergo-type floor whose water
heater died and flooded his place,
ruining his floor. The vapor barrier is great for protection from
moisture outside the layer of flooring, but you
need to prevent any water from inside getting under the flooring - it is
composite and will be trashed by water.
I don't have Pergo, and would not want it for that reason. Pergo
instructions, in part:
"The expansion spaces, all expansion spaces,between the Pergo flooring
and walls, the doorway
transition or other fixed objects such as pipes for radiators, sinks,
water supply to water closet or toilet
flanges MUST be sealed with Pergo Sealant or 100% mildew-resistant silicone.
b. The space around the perimeter of the Pergo floor
must be 1⁄4" wide and sealed prior to installing the wall trim. The 1⁄4"
expansion space must be completely
filled with sealant to avoid water getting underneath the floor."
Here is a link:
As I understand laminate flooring, keeping moisture out of it is CRITICAL.
It's a reasonable assumption since most slab homes do not have the
foundation wall above grade. Usually just a footer and slab with sill plate
on the perimeter. But who knows, it could be a unique construction.
In any case, I would seal it unless the OP can find evidence it really is a
drain (like a drainpipe or sump pit nearby) Use a flexible caulk urethane
caulk should be effective and not too expensive. Silicone or Silicone II
caulk will work albeit at a higher price. Don't bother with latex caulk, it
keeps airtight but will fail if water pushes from outside. Even if there is
not a water problem, sealing will keep things like radon gas out (if your
location is prone to that)
I was going to cancel my last message - my brain finally clicked in.
So, it's a basement. Back to the
Pergo instructions.........also say not to install the flooring on a
floor with a sump or a floor drain.
Thanks to all for responding. Sorry for the delay in following up.
No basement, no French drain, no water seepage. The gaps are in the
bedroom, between the slab and the sill plate, along the two outside walls.
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