Frequently asked questions

This is where you will find most answers. If there should still be any questions left, don't hesitate to contact us.


General

DO I NEED AN ENGINEER FOR MY RETAINING WALL?

See why there is more to it than you think.

In Australia council regulations may vary. For example in SA a retaining wall over 1000mm high needs council approval. Other states stipulate 600mm as the limit but in all states in order to get council permission the retaining wall needs to be designed by an engineer. The higher the wall the higher the risk of danger. Simple when you know how. That brings us to the next logical scenario the DIY. Before going ahead with anything check with your local council.
Here are some points to remember.
• If the wall collapsed would it endanger property or more importantly persons?
• If my wall collapsed would it cause surrounding soil erosion?
• What impact would it have on properties around me?
• If my wall didn’t hold would it affect my own property?
The position of a retaining wall can be an important factor, too. If you want to build one on or near your boundary, you may need to get council permission regardless of its height. In rural areas, other factors such as nearby water catchments or the potential for soil erosion may be issues with council.

Take a look at some situations that you may not be allowed to construct a wall or you need an engineers report and council consent.
• In SA most councils require approval for a wall and fence combined height over 2.1m
• Retaining walls to be built over easements need council approval from the easement owner eg. SA Water
• In most cases Walls must be away from easements by at least a metre away this includes sewerage pipes and water mains
• No wall can cause water to flow into a neighbours property
So here is where common sense prevails. If you are not sure its best to seek the services of an engineer. So what if you have a wall to build that is less than a metre in height and doesnt need an engineer? In some areas the regulations may be different where 600mm or 800mm is the limit and some restrictions may apply there. This is where an engineer may help. We can arrange this service. 

If in doubt call us we have engineers we have worked with and trust every day and can help you with any building, design approvals you may need. 8395 0300

WHY GOOD DRAINAGE IS IMPORTANT

When it comes to retaining walls we tend to think of the material and how it will be constructed..

See why there is more to it than you think.

GRANULAR SOLUTION.
Drainage of rainwater or other wet conditions is important in the stability of a retaining wall. The backfill can be saturated which then increase the pressure on the structure and making it less effective retaining the backfill of the wall. This can lead to sliding and ultimately destabilising the wall. Granular backfill is a solution that helps with the drainage adding easy compaction and increased sliding resistance.

WEEPHOLES AND DRAINAGE LINES.
Weepholes are used to run through the wall and provide drainage behind the wall. Minimum diameter usually for most walls. Larger walls can use 10 cm weepholes with adequate spacing between the holes allows uniform drainage. A filter should always be used between the wall and backfill to avoid clogging and loss of backfill.
Perforated drainage holes wrapped with geotextile or buried in a granular filter bed carry water to the weepholes from deep within the back of the wall.

Dont take any chances call us to make a time to assess your wall needs and how best to begin your project.

 

 

 

WHO PAYS FOR MY RETAINING WALL?

When it comes to retaining wall costs it is the most heated and emotionally argued subject between property owners.

Where do the retaining wall posts go? Is a retaining wall the shared cost and responsibility if it's built on the boundary? The most critical thing to keep in mind is the lay of the land. Where does it slope? How steep is the angle? How will this affect my and my neighbours retaining wall drainage? All these points are of importance when a properties natural lay and fill is altered. In most cases and generally speaking, each individual owner is under obligation to keep their soil retained when they have excavated or added to the natural soil level.

A little cooperation can go a long way for both parties.
This will save you money on the cost of retaining wall construction individually. Things to discuss would be types of retaining walls whether it will be a sleeper retaining wall, gabion retaining walls ? etc. So to answer the question if you fill and your neighbour excavates you are both responsible for the amount you either support or fill. So if for example, you set up a sleeper retaining wall to fill above the ground level of around 300mm and your neighbour digs 700mm below the ground level. You pay for 30% of the wall and your neighbour for 70% of the cost.

As always when thinking of retaining walls its better to be safe than sorry. 
Get qualified help as in a licensed retaining wall builder. They are skilled and experienced in how to build retaining walls with proper insurance and cover for construction during and after the project.

Call us as we have the experience in the Adelaide landscaping scene to help with any disputes or questions before you start building. We’ll assist in costing the project and the individual retaining wall cost for each parties.

CAN I BUILD MY WALL ON MY PROPERTY BOUNDARY?

Yes, you can. But check the Development Act of 1993. Here are some things to think about.

There it states that included in the design is the allowance for future work below the wall to a maximum depth of 600mm.

So check your local requirements before you start to build anything. A few things to keep in mind. Building retaining walls near common boundaries. So where exactly are your boundaries? Check first where your property lines lay. Sometimes the best way is to check the house plans. Unless a survey has been taken or a fence put up recently with the boundary markings in place you won't know exactly where these are. You need to make sure their exact position before any construction begins. On the other hand building, for example, a sandstone retaining wall away from the common boundaries by several metres may not need the exact location of these markings. Keep in mind if it’s in the vicinity of the property lines that your local councils or regulations may need you to get a building permit.
This is where we can help in getting the permit and assisting you with the finer details of the construction of the wall. For example, in some places in Australia, a retaining wall cannot be closer than 600mm to the boundary. In other states retaining walls should be no closer than 900mm to the boundary.
There are differing regulations so make sure you check with an expert wall builder like us and we can organise a surveyor to ensure exactly where your property lines are.
check with an expert wall builder like us and we can organise a surveyor to ensure exactly where your property lines are.
Also, if you’re planning to build a sleeper retaining wall near your front road boundary there are more things to consider and applications to think about. For instance, if your property is larger than 450 square metres your wall should not be higher than a metre within 6 metres from the road.
If you definitely want to build a retaining wall on an existing boundary line then you need to be working together with your adjoining neighbour or owner of the property to obtain the correct approvals and relevant permits before you start any work.

These regulations and approvals are there to protect both interested parties from damage.

If you’re the sole party that will gain benefits from building retaining walls on your boundary, then council will need to be convinced:
• that your retaining wall will not impact the stability of the soil on the adjoining property;
• Sufficient retaining wall drainage. No water running off the wall will damage other property; or
• The retaining wall you construct will support the natural lay of your land.
If you and your neighbour agree to build a sleeper retaining wall on your common boundary then building approval and permits will be needed. Payment of the wall may be shared by both parties. Depending on the various cases council may require one party to pay more for the concrete sleepers price if they benefit more from the wall.
Retaining wall regulations may vary and get complicated for lots of reasons. Local council can help you navigate through various approvals, permits.

For quotes on a concrete sleeper retaining, sleeper retaining wall or gabion retaining walls check with us a professional wall builder we have the expertise and knowledge make sure things go smoothly and complies with all the requirements for you to enjoy your retaining wall.

CAN I DO MY OWN COUNCIL APPROVAL?

Retaining walls purpose whether a sleeper retaining wall, gabion retaining wall, sandstone retaining wall is to support soil that is not naturally retained.

Because we need to produce a structure to allow us to retain this soil it can have an effect on surrounding areas and the retaining wall cost. There is also the safety issue here that is vitally important. A wall built incorrectly is in danger of collapse. Council approval is often needed before you start building a retaining wall. So keeping in mind the above. Yes! you can do your own council approval you will however require;

• Two sets of Engineering
• A Certificate of title from the Lands Title Office.
• Two sets of your Builders site plans highlighting wall heights and positions.
• The provision of a building certifier to make inspections during the build to ensure correct specs.
• Council applications fee, approval should take around 10 weeks on average.
• Different councils require additional information. Check with us or local council first. 

Structures like a flower bed raised in the garden away from the boundaries or a vegetable bed probably don't generally cause severe damage or threaten safety. Below are a few points to remember for getting council approval for your retaining walls.
• In areas of Australia, the height of a wall before council approval is 1 metre some are 60cm or 80cm
• Some states require council approval when a wall is less than 1.5 metres away from another wall or structure.
• Walls must be usually away from easements by at least a metre away this includes sewerage pipes and water mains.
• No wall can cause water to flow into a neighbours property.
Remember that personal safety is the key here as well as the integrity of surrounding structures.

Always check with experienced retaining wall builders and your local council before you think about building. So if in doubt make sure you get your professional retaining wall builder to go through your requirements and advise on retaining wall cost and get you started with the process. We’re here to help.

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