On Apr 3, 2:53 pm, wrote:
The OP is talking about the expansion felt or foam that you would put along a building, retaining wall, or other
slab that you would want the new concrete to move independently of.
Two totally different things.

If it were against my house I'd want foam with lots of caulking. No
felt next to the house! I'm no expert, but I dn't think I've ever
seen felt next to a structure. You would want something waterproof
like caulking.

I'd take them at their word. Expansion strips are very easy to
install, and if they are trying to get out of spending 5 minutes
putting in 5 bucks worth of expansion joint, then they are shoddy
indeed. Be different if it was poured between two buildings or it was
a very large area. Cutting joints is often done these days. These
are control joints, not expansion joints, and their purpose is to
confine the cracking to the cut joint. At least that's the theory--
i've often seen concrete crack independently of the control joint.