forming sidewalk up against exterior XPS foambaord insulation
I'm pouring a sidewalk up against a exterior insulated slab as shown below. My situation is a little different because I have 1 course of split face block on the perimiter and framing on top of that. I want to keep the block exposed. If I hold the 1.5" XPS down 2" from the top of the sidewalk will the concrete break out over the thin concrete? My sidewalk is planned on being 3.5" thick x 42" wide x 34' long. Would it help at all to thicken the edge of the walk to 4 or 5" where it meets the foamboard? Kind of like a mini monolithic slab sidewalk?