I'm having our AC replaced and our current condensing unit concrete pad (32" x 32") is too small to support the new unit. I'm guessing this isn't an uncommon problem with the higher efficiency units having larger exchangers. I searched this thread but couldn't find anything with the same question. Sorry if it's a repeat, which it probably is.
The installer wants to use a 3" thick resin pad (42" x 42") for the new unit beside the existing pad directly on the ground.
Is the resin pad on the ground a better setup than trying to "extend" the pad by adding concrete blocks (CMUs)? The new pad would hang over and be supported by concrete blocks for about 10". I guess I would be concerned with the concrete pad not moving at all but the concrete blocks moving during the winter.
I guess extending the pad with more concrete would be ideal, but my install is scheduled for Monday, and wanted to see if the above options would be okay?
We live just outside of Washington DC, so the winters do get pretty cold.
Thanks for any input!