Decks, Patios, Porches and Docks - Low deck over old concrete patio

I'm planning to build a deck that will stand about 18'' above an old concrete patio. The patio is in good shape, but I'm not sure if using it as a support for my deck is a smart move. The frost line in my region is about 32" to 36".

Do I need to break through the concrete so that I can bury my posts below the frost line or can I use Strong-Tie's or Dek-Blocks on top of the concrete patio?

I also did this, but the edge of my deck went past the area where the concrete eneded. I was able to put footers there. But I also supported the area over the concrete patio with deck blocks that I used to support some 4x4 beams that ran the lenght of the deck. That supported the middle part of the deck.

I don't know that I would suppot the entire deck with deck blocks over the concrete. I guess it would depend how much the concrete pad settles over time. And if the concrete pad is sloping away from the house or not.

What size deck are you building?

It's going to be about 14' x 20'. That's the exact footprint of my concrete patio. The patio does have a pretty sizable crack in it, but I don't see it going anywhere.