Retaining wall blocks are modular concrete units that are placed in a specific arrangement to create a retaining wall. The blocks are laid at angles ranging between 69 and 91 degrees to create strong structures. Applications range from cut slopes to attenuation ponds and embankments. Due to the blocks manufactured beforehand, installation is economical and rather quick compared to the construction of alternative structures.
The prices for concrete blocks depend on various factors, such as:
- Product choice.
- Block colour, as the coloured ones are more expensive than the grey ones.
- Construction angle.
- Wall height.
- Work face accessibility.
- Whether it is a close-face or open-face installation.
Pricing matters, of course, but if the retaining wall blocks and the construction approach are selected based on price rather than function, durability, and strength, then the risks must be considered. As with any kind of construction project, quality should always be more important than price.
True, over-priced products for the sake of a brand name are not worth the consideration. However, installation of a retaining wall is normally where soil must be kept at bay, erosion controlled, and landslides prevented. It is also for aesthetic purposes, but as the name suggests, it keeps the soil from a higher surface area from falling or sliding onto the lower surface area. The retaining wall must thus be able to bear considerable weight and keep the weight behind it in place. The types of materials used determine the strength, the appearance, the drainage ability, and safety of the structure.
Although contractors compete for projects and thus offer exceptionally competitive prices, do not compromise on the quality of the products. The engineering integrity of any such a construction project must be the first and foremost consideration. Structural failures have increased over the years because of sub-standard products and construction. The money spent beforehand to ensure superior quality is worth every cent.
A life lost because of a structural failure cannot be valued in money. Likewise, the cost involved to rebuild such a structure after failure and the expenses regarding rehabilitation of the area where soil and concrete have spilt over after a landslide can run into hundreds of thousands of rands.
Apart from the client that commissions a project, the contractor should consider how project failure can affect his company’s reputation. Factors that must be considered when quoting the price for installation of a retaining wall include, but are not limited to:
- Provision for unknown seismic events.
- Provision for flood conditions due to heavy rains.
- Total dry weight to carry and keep back.
- Total wet weight to carry and keep back.
A structure that is compromised due to the materials used or the way it is constructed is unacceptable. Even if the part that is non-compliant with regulations makes up less than 10% of the overall compliance, it is already an extremely big risk. That non-compliance or compromise eventually causes extra pressure on the entire structure. The durability of the structure is thus compromised. Any retaining wall above 2,5 metres must be designed according to the results of the geotechnical report. Any wall above 2 metres in height must be designed by a relevant engineer.
When it comes to product integrity, only buy from trusted suppliers. A cheaper block made from sub-standard cement is simply not strong enough to carry the soil weight. It is imperative to buy products that are SABS approved as available from MVA Bricks.
As with any construction project, the materials used, compliance with building regulations, and the construction expertise must be factored in when comparing prices of retaining walls. Don’t compromise on the quality of materials and project management. Work with the best materials and teams. Get in touch for product selection help and more information on our project expertise.