Every situation is slightly different, but if the grading is done properly, water is directed away from the foundation with a French drain (if needed) and gutters are installed the cement work seems entirely unnecessary. Likewise, the cinder block "room", replacement of the deck with a poured concrete patio. Cement work is inherently expensive. Unless this company can explain to your satisfaction why it is essential, I wouldn't do it. At the very least, I'd ask at least one other company for an evaluation.

Thanks for your advice! The concrete was actually my idea (haha). The contractor suggested putting flashing around the foundation and then adding soil to grade away from foundation. I asked about the concrete because it seemed like a more permanent and waterproof solution. He's coming back today for a second look to finalize plans and I will ask him about just doing the flashing/grading and possibly a drain around the back perimeter (which sounds like a good idea, anyway).

I feel we have to remove the deck and fill in that room because it's so horribly constructed (a deck constructed on top of an open hole in our basement, with just foam insulation separating our house from everything outside? insane! there's no door between our house and the basement, btw). The deck is also rotting from being exposed to so much rain and never being cared for, so it's an eyesore anyway.

We've had two other companies come out-- there aren't many options around here. One were total shysters who just wanted to put plastic sheeting on the inside of our BRICK foundation and force the water to run behind it into an interior drain (while growing mold and ruining the foundation)---SO stupid, and for almost the same amount of money as actually fixing the problem. The other could only do a vapor barrier in the crawlspace and install a drain outside. The one we're working with now can do anything we need and is the only company like it around here.

Switching to flashing/grading on the sides sounds great (while keeping the concrete patio)-- I'll ask him about that today. It would be really nice if we can get the cost to $5,000.

This is exactly the problem I have what a coincidence, demolished the deck which was falling apart and notice moisture coming from the way underneath the deck, we do not know if there is a hole like you mentioned in yours but it wa built around 1940s God knows what kind of bylaws they had if any.

Please share what was the solution, I do think that a concrete pad should push water or at least keep water further away from the foundation walls.

Appreciate any updates.