A retaining wall is a structure designed and constructed to resist the lateral pressure of soil, when there is a desired change in ground elevation that exceeds the angle of repose of the soil. Commonly used materials for retaining walls include timber, treated timber, concrete blocks, steel, stone, brick, and various other materials.
Timber retaining walls are usually made of pressure-treated walls, which are treated with chemical preservatives such as copper-coated chromated copper arsenate (CCA) to protect the wood from rot, decay and termites.
Pressure-treated walls can be left untreated, stained or painted.
Concrete block retaining walls are made of masonry or reinforced concrete blocks and can be mortared or dry laid. They are a common choice and are perfect for areas that are prone to flooding or high levels of moisture.
Reinforced concrete block retaining walls can withstand heavier loads and provide extra stability against lateral pressure.
A steel retaining wall is a versatile and durable choice suitable for all types of landscaping project. Made of corrugated steel panels that are strengthened with angled supports, they are extremely strong, low maintenance and less expensive than conventional block retaining walls.
Stone walls are one of the most attractive and longest-lasting materials used for retaining walls and are perfect for use in natural and rustic settings. They are composed of various types of stone and rock, including granite, limestone, flagstone and sandstone.
Brick and block retaining walls are also popular for their ease of construction and varied design and aesthetic. Common types of brick used for retaining walls are clay, sand-lime and concrete, fired clay and fly ash bricks.
Regardless of the type of material chosen for your retaining wall, be sure to consult with a qualified structural engineer or a local licensed contractor to ensure that your wall is constructed correctly and safely.
What type of retaining wall lasts the longest?
The type of retaining wall that lasts the longest is a gravity wall. Gravity walls are constructed of concrete or masonry and lean back towards the soil they are holding back. They are very strong and effective because they rely on their own weight to resist the pressure of the soil behind them.
They do not require additional reinforcement in the form of ties, anchors, or piles. Furthermore, gravity walls can last for decades if they are built properly and with quality materials. They are also more affordable than other types of retaining walls and can be built with environmentally friendly materials.
In addition, a gravity wall is a very durable option and can handle large amounts of pressure from the soil. It usually does not require as much maintenance as other types of retaining walls and its life expectancy can be extended by reinforcing it with steel rods.
Gravity walls also do not suffer from significant environmental damage, such as erosion or root infestation, that can affect other types of retaining walls over time.
How do you save money on a retaining wall?
One option is to use inexpensive materials, such as railroad ties or concrete blocks, rather than more expensive alternatives like brick or stone. Installing a wall yourself using DIY kits is another way to keep costs down.
If your retaining wall is on a slope, consider building a terraced wall to reduce the height and length, cutting the cost of materials and the amount of labor needed. Utilizing the natural terrain and integrating the wall with the landscape can also help keep costs down.
If using concrete, be sure to use a coarse mix rather than finer to save money. Additionally, opt for less expensive finishes, such as broom-swept concrete, or forgo a finish altogether for a more rustic look.
You may also be able to rent tools and equipment to keep costs down. Ultimately, the best way to save money on a retaining wall is to shop around for materials and compare prices, as costs can vary significantly from one supplier to the next.
Do you need drainage behind a retaining wall?
Yes, it is necessary to have some form of drainage system behind a retaining wall. Properly installed drainage can help to ensure that the wall stands up to the elements and does not become overwhelmed by water pressure.
The system should be designed based on the characteristics of the soil, the amount of water present, and the size of the wall. A helpful first step is to dig a drainage trench behind the wall, which helps to divert water away.
Another solution is to install a geotextile fabric, used to keep soil particles from entering the wall and clogging the drainage system. After this, gravel and perforated drain pipes should be installed to allow water to pass through and away from the wall.
Finally, the drainage trench should be covered with soil and gravel to protect the pipes and provide additional drainage. Doing this will reduce water pressure against the wall, ensuring that it will remain stable and secure.
How long will a pressure treated retaining wall last?
The lifespan of a pressure treated retaining wall will largely depend on the environment its in and how much upkeep it receives. It also depends on the longevity of the wood used for the construction.
Generally, pressure treated wood has been treated to resist rot and decay, so it should last for many years. If the retaining wall is made from a high-quality wood such as cedar, it can last for decades.
On the other hand, if the wood is of a lower quality, it may start to degrade and need repairs or replacement more quickly. Regular maintenance such as periodic staining can also help extend the life of a pressure treated retaining wall.
In a general sense, a well-built and properly maintained pressure treated retaining wall should last anywhere from 20 years to as long as 50 years or more.
How thick does my retaining wall need to be?
The thickness of your retaining wall will ultimately depend on the height of the wall and the soil conditions behind your wall. For non-engineered retaining walls, which are typically up to 4 feet high, a minimum thickness of 6 inches is recommended.
This can be increased to 8 inches to add additional strength. However, if your wall is higher than 4 feet, an engineered retaining wall may be necessary. The thickness of engineered retaining walls will be determined by a structural engineer depending on the site and soil conditions.
Can you DIY a retaining wall?
Yes, you can absolutely DIY a retaining wall. Before you start, however, it is important to make sure you not only have the right tools for the job but also the right materials and the proper permits, especially when working in your own backyard.
Once you have made sure you have everything you need, it is time to begin. Start by preparing the area where you will build the wall by removing any grass and weeds, then you’ll have to dig down a few inches to create a level base for the stones or blocks that you will use to build your retaining wall.
You’ll also need to place and pack gravel along the area in order to provide drainage and to help keep the stones or blocks secure.
When your base is ready, you can begin to arrange your stones or blocks in the desired pattern and secure them with mortar. Using a level and trowel is important for a straight and secure build. As you are going up the wall, make sure to create a few layers that overlap by about one-third so each layer builds upon the strength of the one beneath it.
Once you are done, you’ll need to backfill with soil to secure the wall in place. After you have finished the backfilling, give the wall a final pass with the level to ensure it is level and secure.
DIY-ing a retaining wall is possible with some planning and the right steps. With the right tools, materials, and permits, you will be able to create and secure a wall that not only looks good but will last a long time.
Can cinder blocks be used for retaining wall?
Yes, cinder blocks can be used for retaining wall purposes. Cinder blocks are often used for retaining wall projects due to their low cost, their ease of installation, and their durability. When building a retaining wall, it is important to ensure that the cinder blocks are laid in a secure and stable pattern, as well as using mortar in between the blocks.
This will help to ensure long-term stability and strength. Additionally, soil should be placed behind the wall and then backfilled to provide additional durability and support. Properly installed, cinder blocks can provide a very effective retaining wall.
Does a 3 foot retaining wall need drainage?
Yes, a 3-foot retaining wall should have drainage. Without proper drainage, rainwater and other runoff can collect behind the wall and create excessive pressure, which can cause the wall to collapse.
Installing a drainage system can help prevent this by allowing any excess water to escape. There are two primary types of drainage systems used in retaining walls: perimeter drain and blanket drain. A perimeter drain consists of a pipe that runs around the base of the wall, collecting runoff water and directing it away from the wall.
A blanket drain is an aggregate material (i. e. gravel) which is placed between the soil and the wall, and forms a blanket which collects and carries excess water away from the wall. Both systems are important for maintaining the integrity of the wall and should therefore be taken into consideration when planning a 3-foot wall.
