Fill crack between concrete walk and foundation

I favor a polyurethane caulk. For a neat application use masking tape. (on concrete duct tape may be easier to use) and remove before the caulk has begun to fully cured...a few hours after application.

Make sure to use a backer rod to limit the amount of caulk used. It will result in a better job.

Before you throw time and money at the situation- does the sidewalk slope AWAY from the foundation? It is quite common for walkways and patios that butt up to foundations to frost-heave upward on the outer edge, since the inner edge is kept warmer by the foundation, and seldom heaves as badly. If water ponds against the foundation, nothing will hold up very long as a seal. If it is sloped toward the house, mud-jacking or replacement are the only real cures.

But having said that- Usual practice for a joint like that, depending on how wide it is, is clean out all the old gunk, and shove in some rope caulk (made out of plastic foam these days), and then put the expensive gray rubbery stuff over that. The rope stuff is cheap, and you only need a thin coat of caulk over it. The rope comes in different diameters. One of those heavy D-shaped ice scrapers on a long handle comes in handy for forcing the rope down into the crack, otherwise you will end up with a real sore wrist using a screwdriver or putty knife. What you are trying to avoid is open pockets in there where ice can form and push everything apart.

-- aem sends....

Forget the home stores on this and go directly to your local concrete products supplier. They have a vast array of construction and traffic sealants that will far outperform anything that you can get elsewhere. After all, that is ALL that they do.

Here is the Percora website with their supplies, just to get you started:

They will be more expensive, but you won't have to redo it every six months to keep it looking good. After you look at the staggering array of products available to do what you want to do, contact your local supplier. Tell him what you are doing, and he/she will point you in the direction most suited to your need, quantity, and price range.

Great suggestions from everyone -- many thanks! It's exactly what I was looking for.

(The slope is indeed still higher on the house side of the sidewalk and water drains away from the house, so that's good news for once.)

~JMEA