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filling concrete gap of 1 inch

derbrad's picture

I have a concrete pad which was butted up against another concrete pad from my porch.  A 1 inch gap has occured as the pad has moved away from the porch pad/foundation.  What material can I use to fill that gap that won't just crack in a year of so?  I was gong to first fill the gap with sand and top off with another material but not sure what to use.

The two slabs will inevitably (post #201426, reply #1 of 1)

The two slabs will inevitably move relative to each other, so no hard substance you put there will survive long without cracking (and it's especially true that you wouldn't be able to make a smooth, invisible joint).

You could use a pourable crack filler.  This is a sort of caulk that is intended for filling cracks like this, though 1" wide is a bit wider than ideal for it.  The stuff sets to a rubbery consistency (though I believe it can take weeks, and it will need to be protected from rain for awhile).

You could fill part of the crack with a strip of rot-resistant wood, then use gun-type crack filler in on either side.

You could insert one or two fiber expansion joints and then pack in some sort of mortar.  But it's unlikely that any sort of mortar would work in so narrow a slot without some cracking.

Probably two or three other options.

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