New 4x4 Step Block caps add a clean finish

NEW 4X4 STEP BLOCK CAPS

The new 4×4 Step Block cap

The 4×4 Step Block caps installed at the ends of the terraced seating sections Curved seating at Durbanville Preparatory School

add a clean finish

The interlocking nature of concrete retaining blocks provides limitless scope for amphitheatre and landscaped seating, along with access stairways. A prime example is a project completed for Durbanville Preparatory School in the Western Cape constructed using Terraforce’s 4x4 Step Block™ system.

Early in 2022, Durbanville Preparatory School elected to upgrade its sports facilities by reorganising one large field on a slope into a sports facility with two new AstroTurf and two grassed fields. These are terraced on different slope levels.

The client had seen similar school projects using the Terraforce 4x4 Step Block and had used other Terraforce block options for retaining and access stairs previously. This led to the decision to go the 4x4 Step Block route – a block that was originally designed by Terraforce as a supplementary accessory for their range of products.

“When used for retaining, the 4x4 Step Block has a unique design that allows you to simply stack up the units with or without mortar, and the corner interlock gently handles convex and concave curves to create single or multiple stairways, seating arenas and ramps,” explains Holger Rust, head and founder of Terraforce. Four 4x4 Step Blocks in a row will result in a flight 800 mm wide.

“The wall angle can vary from vertical to shallow slopes, and steps can be created by turning the block on its side. These blocks can also be rotated for four different elevation choices, and the design allows you to make plants part of your wall,” he continues. He adds that depending on local conditions and the finish required, it may be advantageous to grout the joints with sand/cement slurry.

Durbanville installation

Decorton Retaining Systems, with many years of experience in installing 4x4 Step Block stairs and seating applications, was appointed for the Durbanville Preparatory School project. Together with Klamputs Concrete, a licensed Terraforce block manufacturer based in the Western Cape, they produced a Terraforce precast cap for the L12 retaining wall block units employed as part of the integrated

QUALITY CONTROL

Terraforce retaining wall blocks adhere to local and international standards, having undergone extensive laboratory testing according to SANS 207, BS 8006 and ASTM-D6916-18.

structures, as well as a custom cap for the 4x4 Step Blocks following a special request from the client. Both cap designs were firsttime applications.

“We are thus proud to present the L12 cap and the 4x4 Step Block cap, which are now available as an add-on to finish top row block segments and the ends of stairs rows and seating, where necessary,” says Rust.

An example of a 4x4 Step Block design for a seating arena

Project participants: Durbanville Preparatory School Engineer: Lyners Consulting Engineers Main contractor: DP2 Construction Subcontractor: Decorton Retaining Systems

Design and installation challenges

During the installation phases at Durbanville Preparatory School, the 4x4 Step Block seating configuration required precise cutting of specified units to match the angles of the curved seating sections, as well as the fitment of the 4x4 Step Block end caps. Overall, 10 000 4x4 Step Blocks, 3 200 L12 blocks and approximately 150 caps were used on-site. "Key challenges encountered included the extremely long seating levels, as these needed to drop considerably,” Rust adds, noting that the 4x4 Step Blocks were filled with a dry concrete mix for additional reinforcement.

As a finishing touch, the seating is slightly sloped to allow water run-off over the different levels of the sports fields, promoting efficient drainage and adding to the overall efficiency of the installation.

L12 caps for a neater look