I am trying to replace a door in our stucco-covered fieldstone foundation, the framing to which has rotted away. I tried to anchor new 2x6 lumber (pressure-treated) to the opening with 2.75" TapCon screws ("blue screws") but they just pull out. I'm not sure if the problem is getting a decent hole in the stone, or if I'm really just hitting the stucco and mortar and they're just chipping away. I don't really want to repoint everything right now, but I'm thinking maybe there is some anchoring cement that will hold the screws in. Still, it would seem like a lot of trouble to epoxy in bolts, etc. vs. just being able to drill through the material and drive something in. Any ideas?