Ever since humans started walking the planet, they felt the desire to gather around a focal point to relax, negotiate and entertain each other, while sitting down. Today, these practical seating structures are still very popular, while the method of construction has become more user-friendly and building materials more varied and versatile.
The 4×4™ Step block, developed by Terraforce, a local concrete product licensor with manufacturing outlets all over the world, is one such versatile segmental seating block that lends itself perfectly to the installation of linear or curved seating. Most often the block is used with the standard L range retaining block to build up each step but can also be used as a standalone product to create seating arenas that are hard-wearing and attractive.
Guidelines for installing a 4×4 Step block seating arrangement
Note! Local statutory requirements or site conditions may dictate variations of the below recommendations.
- Excavate and trim to lines and grades as shown on the plan or as directed. Alternatively, the bench to the required inclination as shown on the plan to allow for placement of cement stabilized backfill foundation for seating installation.
- Stockpile sandy backfill material as directed.
- Compact profiled slope as specified by engineer.
- Excavate at the toe of installation for the casting of the foundation to engineer’s detail, with 20 MPa concrete.
- Set out and place the first row of Terraforce blocks to lines, levels and radii as shown on the plan. Fill blocks as specified with concrete or cement-stabilised sand.
- Place cement stabilized (Min 3%) sand backfill and compact as instructed by the engineer. Repeatedly check levels, longitudinally and across.
- Install the first row of Terraforce 4×4 step blocks on a thin mortar bed. Install in groups of 4, filled with wet concrete to allow for insertion of 10/12mm reinforcing bars with overlapping lengths. Refer to the engineer’s specifications and plan.
- Place and compact cement stabilized backfill as before. Repeat progressively row by row as work progresses.
- Cut blocks to required angles for a neat match at corners or at sharp bends (see sample illustration and photos.)
- Place 50mm screed in matching colour (or paving stones) behind the front row of 4×4 blocks of the seating area as shown on the plan. Note this step may be undertaken once all the block rows have been installed.
- Install lines of access stairs with 4×4 step blocks as shown on the plan and section.
- All visible in situ concrete for screeds, wedge fillers etc, to be in matching colour and with a neat, brushed, non-slip finish.
- Supply and install subsoil drainage system where and when specified by the engineer.
- Install a new rainwater channel along the top edge of the installation as per plan.
- For best results, all work should be executed by an experienced contractor. Consult terraforce.com for a list of recommended Terraforce contractors in various regions.
General Notes
Cement slurry completes seating arrangements with matching colours for a uniform finish. Supply and fit railings, screen or wing walls, complementary paving, or landscaping, as shown on the plan.
Make good in matching colour, any blocks that were chipped during transport and installation. Refer to Question 30 of the Question-and-Answer section.
Notes and details shown are selected from a variety of existing installations. Ultimately the designer and his supervising agent will make the final choice. For more information on the 4×4 Step block.