The gap, no more that 1/4 inch, is between a concrete sidewalk and
vertical metal walls surrounding steel metal doors that cover stairs to
the basement. The concern is water getting in the gap, then freezing in
the cold New Jersey winters, expanding and damaging the concrete.
I couldn't find any caulk in Home Depot that specified both concrete and
metal. That may be just because the situation isn't that common, and one
of the caulks may very will do the job without having to be replaced
every couple of years.
I'm agreeing with the silicone suggestions.
Do keep in mind, however, that not all silicone is created equal.
In tests, the strength can vary by a factor of more than TWO! (I wish I
still had the links..I believe I started somewhere on Gluguru.com's
site. Either way, it's one helluva site for adhesive information. They
even have an adhesive that will stick to Karl Rove *G*)
I am not affiliated with Gluguru, btw.
Stick to GE. They make most of it in many grades for just about all
'Silicon II' they keep to themselves, so it seems....it's by far the
best of them all. (Aquarium builders insist on that one, I'm told.)
I'd be careful with silicone. Unless it specifies that it is OK for
concrete, it will not adhere. The strong vinegar smell is acetic acid
and will attack concrete - no bond.
Urethane caulking would be a better choice. Clean the substates and
consider a backer rod.
Amen, it is refreshing to hear another professional who knows
that silicone doesn't stick to much of anything. The only one I
would consider using is Dow Corning 795. The urethanes are a much
better caulk alternative most of the time. Butyl rubber is very
difficult to tool and control, but is still the best for certain
(top posted for your convenience)
Keep the whole world singing . . . .
DanG (remove the sevens)
I have to third the motion about using silicones. I have yet
to find anything that they adhere to for very long except
maybe glass. Urethanes or butyl are the way to go. As an
example, I do alot of leak repairs and when the
owners/maintenance people use silicone to try to repair a
leak, the explanation is always the same; We had a leak there
and sent the guy up to fix it and it stopped for about 6
months. Now it is back.
I can go up on the roof or side of the building, find the
strings of silicone laying on the roof (or swinging in the
breeze), pull it out and do a real repair. It does make
finding the leak a bit easier.
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