brickconcretefootingsslope
Going to be building a retaining wall in the front yard on a slope. I'm going to be using King size residential bricks to make a 2 wythe wall. Because of the slope I'll need to have 3-4 steps in the concrete footing and was planning that the rise of each step would be the height of the brick plus the thickness of the mortar. Is this the correct calculation for the rise of the step?
Can I convince you to not do this ?
Honestly not trying to be an ass.
Please, please - Get a quote from a company that builds retaining walls.
The quote will cost very little or nothing.
You will be shocked at the cost, and not in a good way.
The quantity of material needed to build the wall, will amaze you.
Please get a quote or two first.
I promise you, you will not regret it.
Block walls work in compression, heavy things directly on top of them is fine.
Side to side, their goal in life is to tip over, and they are damn good at it.
Blocks work because they are tied to very solid, heavy things at the top and bottom that run the length of the wall, and have regular supports at a right angle to the length of the brick.
A 1' deep pile of soil, behind a 4' block wall, 1 block long, weighs 500 pounds.
The path of least resistance is to knock over the wall.
Blocks, attached with mortar, to the soil behind the wall about as strong as a 2x10 resting on its edge.
The question is more one of how many yards of concrete will you need to build the footing.
Those pier blocks or deck blocks are a waste of money. It's not going to be as difficult to dig a few holes and install some real posts now as it will be after the deck is complete and has sunken (unevenly). They might be okay for a light duty shed or dog house, but nothing significant, like a deck.
Edit based on comment:
Best Answer
Finally found an obscure article that confirmed my calculation is correct. The Concrete Masonry Unit (CMU) defines the various sizes of blocks used in US construction. They are each given a nominal size but the actual size is slightly smaller and accounts for 3/8" mortar joints. So when building lets say a retaining wall out of 16x8x8" "cinder" blocks your step rise should be 8" which is the nominal height of the "cinder" block but the blocks actual height is 7 5/8" to allow for a standard 3/8 mortar joint.