On Jun 25, 10:27 am, Pat wrote:

Rico, attachment is common "upstate" to prevent migration caused by
front heaves -- esp. since most patios are floating and don't have
footers to keep them in place.

Another way to do it, is to interlock to big eye bolts (no one said it
was easy) and to put on into the wall and one into the slab (tacked
onto the screen or the rebar) with the "joint" at the border of the
two pieces (in the felt expansion pad) so that the slab can float up
and down without drifting away.

I know it's common, so is questionable construction. The dowels are
silly.

Frost heave is only a concern if there's a chance that the sub-grade
structure will be levered/ratcheted up with repeated freeze-thaw
cycles. There is exactly zero chance of a slab being racheted upwards
as there is nothing sub-grade for the freeze-thaw to work against.
The slab floats on top.

The only thing you have to worry about is the tiny amount of
differential movement between the house and slab, and you pointed out
one way to deal with that.

R