Retaining Wall Cost Guide
Filed under Retaining Walls
A retaining wall is a great way to keep the land from washing and eroding. In addition, you will add beauty and value to your landscape. Building one of these structures takes careful planning and most walls should be done by a retaining wall contractor. It is important to have a general idea of what the cost will be so you will know whether you can afford it or not. This retaining wall cost guide will cover contractors, different materials used for retaining walls and help you create an estimate of the costs involved.
Before Calling a Contractor
When you call out a contractor he will want to check out the land first, so you are not likely to receive an accurate estimate over the phone. Here are steps you can take to start your own cost estimate.
What Size Wall Do You Need?
Go out in your yard and measure where you want to build the wall. It's best to have someone help you measure and if the wall is very long, you may want to use strings and wooden pegs. This will help you envision your new wall.
Are there any special problems you will encounter? In other words, does a tree need to be removed or is a lot of digging involved. This will add to the total labour costs. Also, if the wall is going to be on a property line, you may need special permission from local authorities.
The height of your wall is very important. If it is over a certain height you will need to hire a structural engineer. In most states, any wall one metre or more in height must have the approval of a qualified structural engineer. In some areas, the height limits may be as low as 600 millimetres. But what is a structural engineer?
Structural engineers specialize in foundations, walls, structural beams, posts and footings. Any component which supports a building or structure is part of their concern. Your engineer works in a consultant capacity to your contractor, to make sure the integrity of your wall is built to proper specifications. Even though this adds to the total costs, it is a good way to ensure your wall will last for many years without any problems.
Here are some of the things structural engineers do:
- Supervise construction projects
- Design framework and foundations
- Work with landscape services, architects and many professionals in the building industry
- Design structures to withstand natural forces
- Work with builders on design issues
When you know how long you wall will be, multiply your length times the height. For example, a wall four metres long and 500 centimetres high would be 4 X .5 or 2 square metres. Now, you'll need to choose the materials for your wall and this will have a big influence on the total cost.
This is the cheapest selection for retaining walls. There are three basic timber options:
- Soft woods - pine is one of the least expensive choices and it is
treated to resist moisture and rot. However, soft wood will give you the
shortest lifespan because it will eventually give way to the elements and
time. In fact, you may only receive a 7 year guarantee.
The average installation cost for a pine wall is about $250 per square metre. - Hard wood - treated hard wood is more expensive than soft wood and
it will also last longer. Hard wood is harder to cut and work with than
soft wood and this adds to the cost.
Hard wood averages around $300 per square metre. - Railway sleepers - they make good landscape walls and many people use them for terracing sloping land. You can choose hard wood or soft wood sleepers. Most people choose sleepers for timber retaining walls and the average cost is between $200 and $300 depending on the kind of wood you choose.
Remember, wood comes with a downside. It will not be permanent and will eventually need replacement or repairs.
If you want something impervious to insects and rot,
concrete block is an excellent choice. However, it does not give you the
aesthetics of wood.
When you need one of the sturdiest possible walls,
reinforced concrete is the best (and most expensive option). This is more
labour intensive as a footing needs to be placed and extensive excavation and
planning may also be needed.
Concrete sleepers give you the chance to add beauty to a concrete wall as a number of colours and textures are available. Costs average about $400 per square metre.
This may require the work of a stone mason and takes a great deal of skill to properly lay the materials for your wall. Brick costs average $450 and stone may be cheaper depending on the grade you choose.
If you want a small wall (which is not very high) you may be able to tackle the job yourself. In fact, many home improvement centres provide all the materials you need for the project.
Your contractor will depend on the kind of materials you require. Remember, you may need a structural engineer too. Most retaining walls in Australia can be built by reputable landscape services. They should be able to handle any kind of timber wall, stone and concrete walls for your property.
If you need a reinforced concrete wall, you may need to contact a concretor or building contractor for the job. It might be best to start with landscape professionals and if the job is beyond their expertise, they will recommend the right professionals for the work.
All figures in this article are meant to simply be guidelines to help you get a better understanding of the costs. You actual costs for building your retaining wall can vary significantly depending on the materials and type of labour needed for the job.