I'm looking to build a retaining wall on my sloped backyard. I'll be using cinder blocks (with mortar to join them together and rebar for added stability).
(added info: at the lowest point the wall is going to be close to 4 feet tall, not counting how deep I have to dig and how much of the wall needs to be underground)
1) Footing or no footing? Can I start setting the cinder blocks directly on base gravel, with rebar vertically every 3-4 feet for added stability, and filling them up with mortar as I go? Or do I need footing?
2) If I need a footing, how deep into the ground should my footing be? Not how deep the footing itself should be (I'm thinking I'll go with a 1' footing—feel free to comment on that), but rather how deep into the ground do I need to dig my trench in order to set the footing?
I know that for gravity walls on sloped yards I need to measure 5' out of where I plan my wall to be and dig the difference. What about for cinder block walls, is it the same? Or the added strength and stability of rebar+mortar, or footing+rebar+mortar, makes it so I don't have to dig as much?
Hope the info I provided is sufficient to get help and answers from. Let me know if you need me to try and sketch the design of the wall for added context.