Building a brick stairway is not as easy as it looks. While it appears to be just as easy as assembling building blocks, there is a lot more that must go into building steps than just slapping bricks together with mortar. While it is possible to use an interlocking brick system, they don't always have the desired look people strive for. What most people want is a solid set of steps that they can rely on for years to come.
Measure from the top step to the ground to determine the necessary height for the steps. Clear, level and compact the ground surface of where the steps will go. Surround the cleared area with 2-by-4s to hold the concrete form you will be pouring. Lay rebar out in 1-foot squares that criss-cross each other and fill with concrete to cover. This will create a solid base foundation for the heavy brick steps above. Depth should be 6 to 7 inches of concrete for a sufficient base. Allow to set for 24 hours.
Lay out a base for your steps using concrete brick and block. Think of the outer bricks as a facade. Ideally the depth of the tread when added to riser height should be 25 to 27 inches. You can adjust this as needed, but the riser and tread of each single step should be equal. Make sure the blocks are level with each another, each side lining up to the next. Engineer a tilt into each level at the rear by building up under the rear with a small piece of brick or wood so water will run off each step.
Wet down the outer bricks few hours before using them.
Lay your 1.5-inch-thick paving bricks or class F bricks using a mixture of one part weather resistant cement and three parts fine sand. Lay bricks on the narrow edge to create a flat section for the riser face and with the bottom edge flush with the back of the brick for the tread below it. Between the flat tread brick and the top riser brick leave about a 1/2-inch wide mortar joint. Leave 3/8 inch at the back of the step and 3/8 inch at the base of the riser.
Keep cuts to a minimum by knowing your dimensions ahead of time and purchasing brick to fit those dimensions. A comfortable riser will usually be over 5 inches. Any less and a person's stride will be thrown off.
Do not make your beginning slab less than 6 inches, as this could cause crumbling and your stairs could crack. Water pooling is an enemy to your stairs. Be sure to allow for drainage. Do not use regular brick mortar for stairs, it is intended for wall areas.