Choosing the right landscaping materials to suit your style and budget is often difficult and involves more than just the appearance of the final project. For example, most sloping or otherwise difficult sites need a retaining wall to keep the topsoil from washing downhill during heavy rain and there are several options for this type of construction. Typical choices are timber, brick, concrete or stone and each comes with its own challenges.
Get the Right Approvals for your Retaining Wall
Regardless of what type of material you choose, you may need approval from your local council. Retaining walls, depending on their height and the soil composition they are holding back, are a safety issue if they are not constructed properly. There have been many examples of retaining walls, regardless of the material used to build them, collapsing in extreme weather and becoming a hazard to others.
Need to Know No.1 – Local Authority Approval
Stone retaining walls are a case in point. They are attractive, strong and long-lasting but there are several things you should know before deciding on stone. The first issue is that in Queensland, where we do most of our work, the Building Act requires any retaining wall over 1m in height to have local authority approval. When Dee Gees Bobcats is approached to construct a retaining wall in any material, we check that approvals are in place.
Need to Know No.2 – Design and Certification Costs
The second issue is that again, regardless of the material chosen, local authority approval will require design and certification from a structural engineer. This is regardless of whether the retaining wall is in a garden or part of a structure. From our point of view, cost now becomes a critical factor for clients who have not considered the extra expense involved in this process.
Need to Know No.3 – Importance of Correct Excavation and Drainage
Our major role in the construction of any retaining wall is the excavation and drainage aspects of the job and this is the third thing you need to know. Stone retaining walls require correct drainage as any groundwater behind the wall not properly drained will cause added pressure on the wall’s integrity and make it vulnerable to collapse.
Need to Know No.4 – Stone is Indestructible
One positive aspect of stone is that, if it is installed with all the necessary approvals and certifications, it is almost indestructible. Unlike timber, which is vulnerable to termite infestations and weathering, a stone retaining wall will stand until it is removed by choice.
Need to Know No.5 – Stone Unmatched for Natural Aesthetics
Finally, a well-designed and constructed stone wall will look sensational for many, many years, retaining its shape, appearance and character. It will add natural aesthetic appeal to the accompanying landscaping that is unmatched by any other material.