I have a newly built house with a basement and thus backfilled material within 1-1.5m closest to the house. I am now in the process of building a deck around the house and have heard different opinions about attaching the ledger board to the slab/vault/basement wall. Unfortunately, I don't have the option to lay paving stones/gravel/piers close to the house as I would need to dig about 3m down to undisturbed soil. From the outside in, I have:
-a few centimeters of render
-10 cm of foam insulation
-15 cm of concrete
In the "worst" spot, I have an inner corner where diagonally it's just over 3m to the nearest place for a pier and along the wall 2.7m to the nearest row of piers on solid ground. The plan is to attach a 45x145 ledger board with threaded rods and sleeve anchors that go about 5cm (the length of the sleeve) into the concrete against the wall, then use joist hangers and 45x170 joists (with blocking) which will then support 34x145 decking boards.
I was thinking of using stainless A2 M12 or M14 threaded rods and attaching the ledger board at 60-70cm centers, tightening them quite/moderately hard to create friction against the render to hold the ledger board but not deform the foam/concrete. The carpenters did something similar when they attached our porch and they seem to think it's a good solution.
Do you think it will hold? For those of you who have done similar, any opinions or tips? Should I use double threaded rods vertically, or is that overkill?
