On May 13, 6:34*am, Mikepier wrote:
On May 12, 11:18*pm, Ray K wrote:

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?

Thanks,

Ray

Try the Great Stuff expandable foam.

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?