My front sidewalk is about 40 years old, and is pretty much one big slab from the front porch to the driveway. It's fallen as much as three inches in one corner, which means that rain and melting snow puddle all the time. Also, the surface of the concrete is pretty bad, probably from all of the ice-melting agents the previous owners likely used to deal with the ice build up from the puddling. However, the slab has no cracks in it.
On one side of the slab is a big brick planter, which I'd like to keep. With today's price of concrete, I'm wondering if it's worth it to jack the slab up and refinish the top? Also, I heard of a process that uses Urethane foam instead of mud to jack the slab, apparently it results in smaller holes and less settling. Any experience here on this issue? And any suggestions on the topping to use?
I'm in a cold climate (Northern Alberta, Canada) so frost heave is always a problem (though this problem is probably more related to settling.
Thanks for any and all suggestions.