Top 6 Retaining Wall Defects that could save you big money when buying a home in Livingstone
Buying an existing home? Don't miss out on a prime opportunity to negotiate a potential $10,000 plus on the list price, saving you money on the purchase, to put towards improving the property or preventing potential building hazards.
Whether required by your financier or not, you must ensure that you have money available to perform a building inspection.
Besides educating yourself on the basic standards of retaining building code and your local Councils laws, a professional building inspectors report and the cost associated with the service can be invaluable to your investment and save you a lot of financial strain in the future.
Here are our top 6 defects to look for in an existing retaining wall structure:
Termites: don't be fooled, these little buggers don't discriminate between types of timber. Whether hardwood or pine timber is used, they will make a meal out of any timber retaining wall, and once they've started, it's only a matter of time until they compromise the structural integrity. Yes, timber can be treated with chemicals to prevent termite inundation, but this is merely a delaying process as these chemicals don't last forever.
Weather damage: although weather damage can be obvious to even the untrained eye it can also be hidden from sight. Be sure to check for gaps between the timber post and concrete footing. These gaps can act as a reservoir for water. Once water trickles down into the gap it will remain there for some time as its not subject to sunlight and doesn't evaporate as quickly. This over time can cause the retaining wall posts to rot and eventually fail.
The direction in which it's leaning: a retaining wall should lean, but not just in any direction. Your wall should lean into the side of the hill it is being built against. Australian Building Code requires a retaining wall to have a 30mm lean back towards the cut land. This prevents bulging and cracking of the structure, and subsequent failure should the drainage behind the retaining wall be inundated with water.
Drainage: No matter what material is used to build a retaining wall the drainage system installed behind the wall is the most important aspect to the entire structure. This is also the most overlooked aspect. Because you cannot see the amount of drainage gravel, geo-textile fabric or type of drainage pipe installed often contractors will skimp on these to save a buck. The law states that despite the height of the retaining wall it should as a minimum have behind it a 65mm slotted agi-pipe running the full length of the wall and protruding 300mm out each exposed side. It also must have geo-fabric laid along the entire length and height of the wall to prevent seepage between the sleepers or boulders and finally the drainage gravel must be 20mm in size and be installed at a depth of 200mm from the top of the retaining wall and at a width of 300mm.
Is the retaining wall engineered, certified, and approved by your local Council: It is across all Council's in Queensland including Livingstone that any retaining wall, tiered or not, that exceeds a ground to top sleeper height of 1 metre must be engineered, certified and have Council Building Approval. Furthermore, if the retaining wall is located on a boundary line, doesn't exceed 1 metre in height but has a fence attached to the top that exceeds 2 metres in combined height then it also must be engineered, certified, and approved by Council. We highly recommend before signing any new home contract that you request a copy of the current building approval for that structure. Should the structure not be approved by Council then it is an illegal structure and must be replaced immediately or you risk being fined by Council and given 30 days to rectify the defect.
And finally: if only one or a few retaining wall posts are failing/leaning in the wrong direction, it's not a matter of just replacing those posts or bays. This is a major indicator that the retaining wall is on its last legs. Yes, you can patch the problem by replacing those parts, like so many contractors do, but you are merely delaying the soon to be failure of the rest of the structure. You are far better off financially, replacing the entire retaining wall all at one time than having trades come back time and time again. Which is why Livingstone contractors are quite happy to perform a repair job.
As a fully licenced QBCC retaining wall builder, Rycan Retaining and Earthworks have performed hundreds of earthmoving and retaining wall projects for residents of the Brisbane West and Ipswich region for over 10 years. We've seen it all. 70% of all inquiries we receive is to replace existing retaining walls that have failed. Unfortunately, most people underestimate the cost, value a retaining wall adds to their property and risks associated with a failed retaining wall until it's too late.