Stairs

Stairs

The steps shown here are general guidelines for building stairways. By understanding the basic installation elements, stairways can be easily incorporated into the retaining wall installation. Always check local code requirements before building any type of stair application.

Allan Block Wall Systems offer a variety of options for stairways

Stairs can be designed with flowing curves or straight lines. Curved sidewalls create a softer, natural look. Straight sidewalls and corners offer a crisp, traditional style; however they require AB Corner Blocks and take more time and custom cutting to build.

How Many Steps Do I Need?

Before excavation can begin, the rise and run of the stair treads must be determined and code requirements must be met. To find the number of steps needed, measure the total rise of your slope in inches and divide by 8 in. (200 mm) - the approximate height of a block.

With that information, the entire base trench can then be excavated.

Tackle Your Slope

Match your stairway design to the natural grade of your slope.

• On steep slopes, keep the blocks tight together. With Allan Block, you get an 8 in. rise and a 12 in. run. (200 mm rise and a 300 mm run).
• On gentle slopes, add pavers or other materials to increase the depth of the tread and length of the run.
• Landings can soften a long stairway and provide an easy way to tie sets of steps together.

Take Time to Build in Quality

Building stairs and steps requires careful planning, flexibility on the job site and an eye for detail. Be sure to allow adequate time for layout and building of stairs.

Basic Stair Construction

Our example here uses a base trench of 6 in. (150 mm) and a stair tread of AB Capstones and pavers.

For information on basic installation practices, see gravity retaining wall installation or reinfroced retaining wall installation for more details

• Excavate to the necessary depth and width for each stair riser and thoroughly compact the entire area to 95% Standard Proctor with a mechanical plate compactor.
• Check for level.
• Starting at the first step, fill the base trench with 6 in. (150 mm) of wall rock. Rake smooth.
• Compact and check for level. Stairs need extra compaction to avoid any settling later. Better compaction is achieved by backfilling and compacting in 4 in. lifts (100 mm) or less when able.
• Install blocks on the base material. Allow for a space of at least 6 in. (150 mm) behind the blocks for wall rock
• Adjust for level and alignment of each block as it’s installed.
• Install wall rock in the block cores, fill any space in front of and behind the block. When backfilling behind the blocks, fill the entire area that was earlier excavated to create the base for the next stair riser. This should produce a level base for the next set of risers. We recommend backfilling and compacting behind the block in 4 in. lifts (100 mm) to achieve better compaction when able.
• Rake wall rock smooth and compact with the first pass of the compactor directly on the tops of the block and then working in a path that runs parallel to the block. Compact to 95% Standard Proctor.
• Repeat this process for each additional course of steps needed.

Salt for Ice Removal

In colder climates, saltCANNOT be used on the blocks or AB Capstones as it will cause them to deteriorate. Use sand instead.