Using a pressure washer is a good idea.
I obviously failed to mention that if I'm standing in the basement, the
space is overhead. Regular concrete will only drip out before it
sets...I think. Hydraulic cement hardens much faster, I believe.
And I think foam insulation is water resistant, not water proof. But I
may fill some of the void with it so the cement has something against it
in the back.
I had another idea. To systematically use water from the garden hose to
see exactly where the water is coming from.
: > There is a space between my Bilco door and the concrete foundation
: > is about 3 inches wide. Between the door and the foundation is wood
: > unfortunately it leaks quite a bit there. The previous owners (there
: > 20 years) said it leaked maybe twice. Bull.
: > I know it wasn't a definitive fix but I tried caulking above it to
: > prevent the rainwater from seeping down. I can't seem to get it
: > though. So I was thinking of cleaning it up as best I could from
: > underneath and using hydraulic cement (with gloved hands). It would
: > overlay surfaces made of cement, wood, and metal, in that order.
: > I don't really like this solution because the water will continue to
: > the wood, even though it may not leak into the basement. But outside
: > removing the whole Bilco assembly and part of my deck, I don't see
: > way around it.
: > As usual, any advise is much appreciated.
: > thanks,
: > bonnie
There are a few different things called "hydraulic cement" - some do expand
as another poster said. You could use normal thinset (used to set tiles)
and use acrylic admix instead of water to make it adhere better and more
waterproof. The admix is sold where they sell thinset. It does set very
quickly, about 15 minutes, so you have to plan it out carefully and work
quickly. Some stores sell a premium thinset which is slightly easier to
work with and the cost is cheap enough to make that worthwhile. Use all
admix, no water at all, for the thinset.
Use several thin layers instead of one thick layer. If you have a problem
with crossing a deep space use plastic mesh to support the first layer of
thinset. Don't use the metal mesh that is sold for plastering because it
will rust and expand and cause the cement to break loose. You can add
layers on top of each other or beside each other as soon as it is dry
enough that it is hard enough that the second coat doesn't cause the first
coat to move around. Since it will be exposed to air it needs to be kept
damp to cure properly - for at least a day, two days is better.
As with any glue type job, cleanliness counts for more than anything. If
the surfaces are perfectly clean and dry almost anything will stick and if
there is any contamination of the surfaces almost nothing will stick.