I have a 12ft length of sidewalk that has a large gap along my stone foundation. The gap ranges from 2-3". Luckily the sidewalk slopes away from the house and the ground slopes downward toward neighbors house which they installed a drainage system. I was thinking of pouring concrete in this gap with an expansion joint up against foundation. Is this recommended?

The rest of sidewalk has smaller gaps...anywhere from 1/4" to an 1". What about the 1" gaps. I know smaller stuff I can put backer rod with some silca or psl20. It is the bigger gaps I am not sure how to tackle. My neighbor mentioned just filling it with mortar mix but have a feeling it would just break apart with weather and movement.

Thank you for your response.

 

to be sure, that's a hellish width - try this - fill w/fiber reinforced cement & cut in a jnt every 8" or so,,, hopefully the material will crk where you jnt it,,, if that doesn't work, coat w/herculiner you find on ebay - don't laugh - we do it