I am replacing my old deck that was completely rotten. The original was non treated lumber so it just was toast. The deck is only about 2' off the ground and 15' out from the house. It extents 30' across the width of the house. I am using 2x8 joists and double joists around the perimeter. There are 3 original footings for caring the load at the end of the deck but I was wanting to run a double 2x8 beam at 8' to help carry the load and get the bounce out of the 2x8s since I think the max span is usually 11' not 15'. I live in north Idaho where the frost line is 2'.
Can I bury pre cast deck blocks 3' down and run 4x4 posts up to catch the beam? The original footings should carry the max load as it did before, these would just help. The photo below shows placement but the blocks are not buried yet