How to Choose a Retaining Wall Contractor
Retaining wall contractors are like all tradies, there are some good ones, some bad ones, some you would trust, and some you wouldn’t. Here is a checklist of what to look for when obtaining quotes for your retaining wall project so you don't get caught out:
10 Point Checklist
Engineering - All walls over 1m high or within 1.5m of a load bearing structure must be designed by an engineer. Don’t take the risk. Make sure your contractor knows the obligations. See our guide to engineering for more information.
Deposit - As per QBCC regulations, any residential works valued over $3,300 require a contract. The QBCC also state rules regarding deposits which are as follows: If the value of the works is less than $20,000, the deposit amount is 10%. If the works are valued more than $20,000, the deposit amount is 5%.
QBCC Insurance - QBCC Home Warranty Insurance is now compulsory. The amount is determined by the value of the works to be completed. The customer must pay the contractor the required sum. The contractor will then take out the insurance policy on behalf of the customer.
Sleeper Materials - Any contractor who offers timber as an alternative to concrete does not have your best interests in mind. Concrete sleepers are the best option on the market for longevity and sustainability. They have a design life of 30+ years. We offer timber sleepers for smaller walls and garden beds, however the better option is always concrete.
Drainage - Adequate 100mm socked agg drainage pipe needs to be installed behind retaining walls to allow water to pass along the wall into the nearest stormwater connection (if engineered) and not through it. Always check this is included within quotations.
Geo-Fabric - Geo-fabric material prevents soil seepage onto the retaining wall which can cause staining and erosion over time. Check this is included.
Free Draining Aggregate - 20-40mm drainage gravel should be installed behind the wall. It should be installed to a minimum height of one sleeper below the height of the wall and it should be wrapped within the geo-fabric. This is essential to allow water to travel down to the drainage pipe. The pressure of water against walls due to lack of adequate drainage is the main reason for retaining walls failing over time.
Rock - Know where you stand with regards to in-ground obstructions. Quotations should clearly state who takes responsibility for this and also what costs are included.
9. Reviews - Check their reviews online to see what other customers thought of them. If they don’t have many reviews or are anything less than 4 stars, don’t take the risk!
10. License - Ask your contractor to prove they have the correct licensing to carry out your work. You can always check their license number on the QBCC website.
Ensure you check all of the 10 points above before moving forward with a retaining wall contractor. A poor decision can have very bad consequences!
See this example of a collapsed wall below:
Here at RBP, all of our walls are built to engineers specifications, and we have heaps of 5 star reviews! Ask your estimator for more information.
Don’t get it wrong! Go with the experts! Choose RBP :) We look forward to working with you on your next project!
