Retaining Wall Cost Guide & Construction Tips
In our retaining wall cost guide, we discuss all the cost, materials, construction tips to build a retaining wall. Contractor VS professional tips included.
Retaining walls have had a place in lan for several decades now. They are quite useful when it comes to protecting an area from sliding soil, or holding a foundation in place. Also, they are quite efficient when it comes to holding back water. However, gone are the days when retaining walls had to be blunt, dull, and unattractive. With the likes of gabion cages, timber retaining walls, and natural stone blocks, constructing a retaining wall is an opportunity to improve the visual appeal of an outdoor area.
Other than the visual appeal, these walls have a couple of benefits that you should consider before construction. Though we briefly discussed some benefits, let’s explore more of what retaining walls have to offer.
Stopping soil erosion and solving planting difficulties – In mountainous regions, you are guaranteed to face problems from steep slopes and demanding soil grades. These steep slopes are susceptible to soil erosion and make planting difficult. However, retaining walls allow you to level the ground, reduce the effect of stormwater thus decreasing erosion which in turn lets for landscaping.
Holding a foundation in place – Another critical reason why you should consider a retaining wall is to keep a foundation in place. This is often the case where homeowners are forced to build on slopes where bases are susceptible to shifting and falling. Also, you can use the walls where the home lies several feet over the street, or the lawn borders the road.
To separate the yard from the garden or flower bed– Retaining walls are a top way to separate your yard. They are not only useful when it comes to separating the flower beds or vegetable gardens from the rest of the yard but are also excellent when it comes to providing a permanent property line.
Privacy – There are instances where retaining walls will provide better privacy than a typical fence. Obviously, this depends on the height of the wall. Otherwise, they are a top way to prevent your children and pets from leaving the yard.
Dramatic entrance – This is often the case for commercial properties than it is for residential buildings. Most commercial buildings boast robust landscaping and signage. However, this can be challenging in mountainous regions. In some of these areas, it’s not uncommon to have the entrance at the top or bottom of a slope. Retaining walls give you an opportunity to create a high-impact entry.
Mull over these benefits when considering to put in a retaining wall. Also, like any other construction project, there is no one size fits all, and there are several factors that will influence the amount you incur.
What is being retained – There are various reasons why as a homeowner, you might want to put in a retaining wall. Could be that you want to prevent foundation failure, a driveway, a swimming pool or a garden. The various uses will impact the price amount you pay. For most of these engineering is required and this only increases the cost. Walls retaining a garden and are less than 1.5 meters high don’t need consent or design, but any wall irrespective of the height but is bearing an additional weight such as a pool, or a foundation requires engineering and approval.
Location – Like any other construction project, your distance from suppliers will determine the amount you incur. The farther you are, the more you will pay as owing to the higher transportation costs. However, when it comes to retaining walls the climatic conditions of your locale will determine the amount you spend. Some localities experience severe climatic conditions from earthquakes to tropical storms. If you are in such areas, unfortunately, you will have to incur more seeing as your retaining wall require more strengthening, waterproofing, and drainage systems for it to stand a chance against the climatic conditions.
Excavation – First, the excavation required depends on the height of the wall you are constructing, the length, and the gradient of the slope. However, it goes without saying that the more excavation required, the more you will have to pay.
Type of soil – This often boils down to the soils water retention capabilities. Grounds aren’t the same, and some hold water longer than others which is the case with clay soils. Your retaining wall will need more structural reinforcement to be able to withstand the weight of wet soil. These conditions will increase the cost.
Accessibility – Accessibility influences the amount you pay on labor. If the contractor can transport the boulders and bags to the specific location, the cost reduces drastically. If not, expect to pay more as you will have to engage more employees.
Materials used and retaining wall – Materials used for the construction, and the wall design are some other vital factors that will influence the amount you pay. Wood retaining walls are going to be cheaper than concrete retaining walls the same way interlocking walls will be less expensive than rammed earth walls.
Steps – Finally, we have the levels. Some homeowners prefer installing steps either as a precaution against the dangers posed by a high wall, or to increase the appeal. However, expect to pay more for this retaining wall requires more time, and materials.
Retaining Wall Cost
Regarding the fee involved with putting up a retaining wall, they will often vary according to the materials and the design. Nonetheless, most homeowners report paying between $2,800 and $7,700 with the national average being $5,300. There are instances where the price will be as high as $13,000 or as low as $500.
Costs According to Materials
As a homeowner, this is where you have most control on the type of wall you desire. However, you still have to choose the best combination of appeal and functionality. Case in point, it’s probably unwise to use timber where there are soil moisture issues. Your contractor can help you find proper designs and functionality walls.
Cinder Block Retaining Wall
If you are looking for a wall that can withstand the pressure of a wall, building, or carport, and one that is affordable, then you should consider putting in a cinder block retaining wall for only $10 to $15 per square foot. Also, cinder blocks are ideal for homeowners who are looking to put in curves without having to stretch their budgets. It’s quite versatile and easy to put in.
Other than that, it’s long-lasting and isn’t affected by rot and fire. However, there is a downside to these blocks. Seeing as they are secured using footings in the ground, they shouldn’t be constructed higher than 4 ft. owing to stability.
Most homeowners report spending between $475 and $655 to put in cinder block retaining walls. The national average is $565 making it one of the most affordable options. Most blocks don’t vary much regarding price, though the styling can increase the cost. Nevertheless, expect to pay between $1 and $3 for most blocks. At the same time don’t confuse cinder blocks and concrete blocks though they are often used interchangeably.
Though both have a base of 60% to 75% cement, cinder blocks use coal cinders or ash while concrete blocks use fine crushed stone or sand.
Timber Retaining Walls
If you are looking for retaining walls that are low-cost, but attractive, you should consider putting in timber retaining walls. Though it lacks the durability of stone or concrete, you can rest assured that it will serve you for several years before any issues arise. Of the wood option available, it’s best you use pine wood if your budget is tight. However, these lack the longevity and will only last for 7 to 10 years. If you are looking for timber that will serve you for several decades, we advise that you use hardwood which has a lifetime of about 25 years and is resistant to termites. The only shortcoming of hardwood is it’s bit expensive. Otherwise, consider durability class 1 timber or wood treated with a preservative to the H5 rating. Consider these guidelines when purchasing your lumber.
First, if you are looking to use pine logs, you should know that they will last you for only 7 to 10 years which is the same time treated hardwood sleepers will serve you. However, if you are looking for longevity, consider HR5 treated pine sleepers which are highly water and pest resistant and are viable for 20 years or more. However, the most reliable option is railway sleepers. These are planks of wood that were part of railroad systems, but contractors use them for construction. Treated with creosote, these can last up to 100 years. However, this is subject to the time they had been under use.
As for the price, expect to pay between $50 and $350 for treated pine for every square meter, $300 to $450 for hardwood sleepers per square meter and $75 for one railway sleeper, though they are subject to availability.
Also, remember that the integrity of the wall will depend on the piles/posts you use. Often, the piles should be as deep as the wall, but the dimensions will change once the wall exceeds 1.5 meters. By and large, the amount you pay will depend on the complexity of the task, the size of boards used, and the spacing of the posts.
Poured Concrete Retaining Wall
Though not a low-cost option like cinder-block or timber, you should consider poured concrete retaining wall for the durability. Unlike wood, poured concrete has a long-life, and isn’t susceptible to most elements. The pouring makes for a smooth modern finish which is cohesive with the aesthetic of your home. As for the price, expect to pay between $20 and $40 per square foot for a rudimentary retaining wall. If you are looking for a decorative finish say curves, lighting or steps, then prepare to pay more. On the whole, most homeowners report spending about $5,200 to construct a poured concrete retaining wall.
Some factors that influence the price are:
Curves – Curves are always the first consideration when one is looking for a more stylish finish with poured concrete retaining walls. However, they increase the total cost owing to the complexity of the work. More complexity calls for more labor and materials resulting in higher prices.
Reinforcements – There are instances where you will be forced to reinforce your wall against some elements. Despite it being one of the stronger options available, odds are it cannot withstand earthquakes without reinforcement.
Decorative finishes – If you are operating on a tight budget, then an unfinished wall is the most affordable option. Conversely, if you are thinking of adding texture, or color, you will have to incur more.
Engineering – Finally, you should consider the costs involved in hiring a structural engineer. Regulations require you to hire an expert if your wall supports a structure.
In conclusion, we have the shortcomings associated with a poured concrete wall. First, the integrity of the structure is susceptible to harsh climatic conditions. For example, the entire structure can be compromised by a single crack. Also, they might be a hindrance to planting owing to the massive footings these walls require.
Brick Retaining Walls
Brick retaining walls have been an all-time favorite with homeowners owing to the incredulous traditional aesthetic. Also, they are a low-cost option and will set between $14 and $15 for every square foot which is a fantastic price given the aesthetic value, reliability, strength, and durability of brick walls.
Other than the cost per square foot, most homeowners report spending between $2,850 and $7,500 to install a brick wall. Of the requirements, labor is going to be the most expensive at $40 an hour as laying of bricks requires proficient persons and involved labor. There are also some extra considerations you should factor in your retaining wall budget. First, we have the drainage. When constructing your wall, ensure you have drainage options for stability and longevity of the structure. Also, budget for the extra materials such as mortar and the additional person-hours. Were it not for these, brick retaining walls would be the cheapest retaining wall option.
Corten Steel/Metal Retaining Walls
Corten steel/metal retaining wall option is the cheapest you will come across costing between $3 and $4 per square foot. However, this is if you are okay with an unnatural look on your yard. However, other than the lack of appeal, metal retaining walls will serve you for a lifetime. They are long-lasting and quite efficient at holding back water. When considering metal retaining walls, there are various options available. You can install steel walls, use corten steel, or aluminum. The three options are all strong, though steel is stronger than aluminum.
Corten Steel – If you consider putting in corten steel walls, expect a price between $2.50 and $3 for every square foot. Other than the low cost, another reason why you should consider corten steel is because it’s long-lasting and doesn’t rust owing to the steel properties.
Steel – You can also put in steel walls at the cost of $10 per panel or $3 per square foot. It’s low maintenance, and quite lightweight when in galvanized form. Also, it is not susceptible to pests or water.
Aluminum – Though aluminum is a bit weaker than steel, it will still serve the purpose. Expect a price of $10 per panel. The only shortcoming of using aluminum is that it’s susceptible to rust. However, you can coat it to prevent it from rusting.
Though the cost of natural stone is one of the more affordable materials, don’t take this to be an indication of installation cost. Yes, natural stones are cheap to acquire costing between $8 and $12 per square foot, but the construction is anything but cheap. Most homeowners report spending between $25 and $40 to construct one square foot. This price often boils down to the difficulty of working with rocks which increases the labor cost. Expect to incur a minimum of $65 an hour on labor when working with boulders compared to a maximum of $40 when working with bricks. Otherwise, if you are looking for a unique retaining wall and a natural option, then look no further than natural stones. Also, with favorable site conditions, expect to pay between $4,600 and $6,800 for 220 feet of natural stone. However, despite being a green option, natural stone walls have a shortcoming when it comes to retaining water. They are susceptible to massive flows of water, but there are several ways you can construct them such that water flows freely through.
Another benefit of using natural stones for retaining walls other than the natural look is that you can use them for walls 50 feet high. Also, there are various options for you to choose from.
Dry stone – Perhaps one of the low-cost options natural rocks seeing as it doesn’t need mortar. The rocks are stacked up in a way that they are secure and will hold the soil. Also, these design leaves space between the stones that allow water to flow through such that it doesn’t damage the wall.
Sandstone – You should consider working with sandstone if you are looking for a variety of colors and a material that is easy to work with. Sandstone is soft, but durable which makes it more appealing. One weakness of this stuff is that it’s susceptible to moisture.
Limestone – If you are looking for a boulder that is easy to stack, then your best bet is to use limestone boulders. Seeing as they are quarried, they are available in uniform size which makes them easy to work with. Also, they are durable and quite sturdy despite them being lighter than most stones.
Keystone – Keystone has been around for around three decades now and is one of the more trusted brands available. The benefit of using these rocks is that they can easily be stacked over each other with their pin system and are very stable. They are also available in many colors for homeowners looking for a bit of diversity.
Gabion Retaining Walls
If you are looking for retaining walls that can shift with the environment, then you should consider erecting gabion walls. These are a gravity wall system (more on this later) built from galvanized mesh and filled with various material such as stone, concrete or wood. Gabions are designed to be flexible but durable meaning that the structure will shift as the environment shifts and thus not susceptible to severe weather.
As for the cost, gabion walls will compete with most other available options. Expect a price tag between $10 and $15 a square foot. However, you can reduce this price if you have access to free or cheap stones. Gabions can be practical or as pretty as you would love them to be. You can select various colored rocks to fill the gabion and incorporate wood to create steps and sitting areas. Also, the weight of the gabion is enough to hold back the soil, and you don’t have to dig more than 100mm to secure the gabion, unlike concrete or timber where you have to excavate several feet into the ground. As a result, the labor rates will be low as there is little excavation required.
Stone Veneer Retaining Wall
If you want a natural look but at half the price, then you should consider installing veneer retaining wall as these are designed to mimic the look of natural stone. They are also quite affordable which is a plus and will set you back only $3 to $12 per square foot. However, despite being this affordable, they are also quite resistant and can withstand severe weather and other elements such as pests, and rot. Finally, they are low maintenance, lightweight, and the color options are endless.
Other than the materials, you will need a landscaping architect who will set you back between $70 and $150 an hour.
|Retaining Wall Costs||$2,800||$7,700||$5,300|
|Cinder Block Retaining Wall||1 Sq. Ft.||$10||$15|
|Timber Retaining Wall|
|Treated Pine||1 Sq. M||$50||$350|
|Hardwood Sleeper||1 Sq. M||$400||$450|
|Poured Concrete||1 Sq. Ft.||$20||$40|
|Brick Wall||1 Sq. Ft.||$14||$15|
|Corten Steel||1 Sq. Ft.||$2.50||$3|
|Steel||1 Sq. Ft.||$3|
|Natural Stone||1 Sq. Ft.||$25||$40|
|Natural Stone||220 Ft.||$4,600||$6,800|
|Gabion Walls||1 Sq. Ft.||$10||$15|
|Stone Veneer||1 Sq. Ft.||$3||$12|
Retaining Wall Designs
Other than the materials used for construction, you can choose your wall based on the design and functionality of a wall.
Gravity Retaining Walls
A gravity retaining wall banks on its weight to be able to bear the burden of the soil it is maintaining. They are designed to be more prominent at the bottom, and thinner at the top leaning against the surface. This is because the base has to withstand more pressure than the top, and using leverage, setback and total mass, you can design a highly efficient gravity wall. A great example is a gabion wall. Combined with its ability to move with the environment, there is probably no better gravity retaining wall option.
Cantilever Retaining Walls
If your budget is limited, or you have limited space, then you should consider erecting a cantilever retaining wall. A cantilever wall is relatively low-cost seeing as it requires much less concrete compared to semi-gravity, or counterfort walls. A cantilever is a reinforced wall with a relatively thin stem and base. The reinforcement allows the wall to withstand the pressure from the material it’s holding back. The base is split into two parts namely the toe and the heel. Of the two, the heel is more massive and is the part underneath the backfill while the heel is the other part. The general idea here is that the weight the landfill applies on the heel will be enough to hold the wall in place.
The only limitation of erecting cantilever retaining walls is that they require careful construction which means hiring a structural engineer, which only increases the amount you will incur. Also, they are just suitable for walls under 25 ft.
Counterfort Retaining Walls
If you are looking for walls that are similar to cantilever retaining walls in that they are affordable, and require little space but can support walls of more than 25 ft. then you can consider counterfort retaining walls. Counterfort walls use the same tenets of cantilever walls in that they have a thinner stem, but a broad base with a heel and a toe. However, these incorporate counterforts at regular intervals. Counterforts are concrete webs that secure the top of the wall to the bottom of the wall. Together with the wall, the counterforts serve to reduce the pressure on the wall, while the extra concrete increases the weight of the wall.
If you are looking for a wall that requires very little space and can go beyond 25 ft., then counterfort wall is your best bet.
Sheet Pile Retaining Walls
Finally, we have sheet pile retaining walls which are even better for tight spaces than counterfort or cantilever walls. They are also best in areas with soft soil.
That’s it for the available designs. When constructing a retaining wall, ensure it meets your needs first before thinking about the plan. However, most of these will leave you room for design.
DIY vs. Hiring a Pro for Retaining Wall Construction
With the requisite skills and tools, you can erect your wall over the weekend. However, the walls you can construct are limited to below six ft., and walls that aren’t intended to support any structure such as a driveway, carport, or foundation. Retaining walls designed to prop a structure should only be constructed by a professional. You don’t want to risk ruining your property or worse still, that of your neighbor. Therefore, despite the many available DIY kits available for retaining walls, make sure you consult a contractor before work begins.
When it comes to the cost, your investment will depend on the type of wall you are looking to construct.
Concrete Retaining Wall – As for the tools, you will need a level for $12, a caulking gun ($15), a shovel ($15), a measuring tape ($12), a wheelbarrow ($30), rubber mallet ($9), and rakes ($25). Also, you will have to consider the materials, self-stacking blocks, a drainage pipe, and drainage sleeve.
Timber retaining wall – Other than the requisite skills, you will require several tools to erect a timber wall. First, you will need a level that will set you back $12, a utility knife for around $10, a 2-pound sledgehammer to drive the posts into the ground for $15, and a hand tamper for $24. Of course, you will need the essential equipment such as a wheelbarrow for $30, a measuring tape for $12 and a shovel which will set you back $15. Don’t forget the materials, i.e., stakes, the treated posts (6*6 recommended), a drainage pipe to direct water away from your wall, compactable gravel, drainage gravel, and landscape fabric.
One of the top reasons why you should consider DIYing is the money you will save. Constructing a retaining wall is not exactly a cheap affair, and most of the money goes to labor. Get labor out of the equation, and you can halve the cost. Take for instance the labor costs involved with erecting a natural stone retaining wall. At $65 an hour, you will spend around $1040 assuming the task takes two days to complete.
On the other hand, if you DIY, you end up saving $1040. However, there are also downsides to doing it yourself. First, odds are you lack the requisite skills to set up a sound retaining wall. You might end up incurring more on repairs, and reinforcements than you would have spent had you engaged the services of a professional. Also, building a retaining wall is engaging. Not only will you need two days to set up the wall, but you will also have to put in additional hours to educate yourself on the different retaining walls, how to erect them, and still spend time shopping around for equipment, and materials.
Make sure that this is time you have.
However, there is a middle ground here. Other than engaging a landscaping company or doing it yourself, you can work alongside your contractor for the best of both worlds. You will benefit from the expertise the contractor brings, and still get the benefits of doing it yourself. First, you can provide your labor, to divest yourself of the extra cost, or ask to do the final finishes such as cleaning up, disposal, painting, etc.
Tips for Hiring a Professional Wall Contractor
When looking for a sound retaining wall, the first step is to hire a professional installation company. For a more realistic picture of how vital hiring a retaining wall contractor is, in the last ten years retaining wall failure has increased by four hundred percent leading to massive losses and even death.
Licenses, Insurance, and Experience
When looking for a retaining wall contractor, the first thing you should do is ensure they are licensed and have at least ten years’ experience building retaining walls. You obviously need to know the papers the builder should have and therefore consult with your local authorities beforehand. Also, you will need to see the company’s insurance papers. First, the organization should carry general insurance cause only then can they protect your investment and their workers, a workers compensation insurance should one of their employees get injured, and an errors and omission insurance to protect you against professional acts. General liability insurance does not cover damage as a result of professional actions.
Nothing beats referrals when it comes to getting a credible contractor. Ask your friends, family or neighbors who have erected retaining walls. Best if you ask those who have put on walls in the last six to twelve months. Also, talk to homeowners who hired fraudulent contractors to find out what they did wrong or did not do. There is a lot you can acquire from their experiences and perhaps avoid hiring a crook.
Better Business Bureau
Before you ask for estimates, check your shortlisted company’s reputation on the Better Business Bureau (BBB) or Angie’s list. These institutions are designed to help homeowners find proficient builders. Check to see if the contractor has any unanswered complaint, or how satisfied previous clients were. Read any negative reviews as these might point out potential pitfalls.
Once you have narrowed down to several credible contractors, ask them for bids/estimates. Only work with contractors who are willing to provide estimates after an in-person evaluation. Though appraisals are free owing to increased competition and economic conditions, don’t reject contractors who will charge for the assessment. Matter of fact, engage them as this shows they value their time. Expect the prices to vary from company to company as different institutions have different overheads and expenses.
And though you might be driven to pick the cheapest offer, this isn’t necessarily the best choice. Most homeowners who have reported retaining wall failure fault going for the least expensive contractor as the number one reason for the failure.
Tips to Avoid Retaining Wall Contractor Scams
As pointed out earlier, homeowners have lost millions in property damages and even lost lives owing to failure in retaining walls. Also, millions have disappeared with fraudulent contractors who fail to finish the job once payment is made. The good thing is, there are a couple of ways you can avoid falling into the traps of these swindlers. The first and most obvious one is to take a look at their insurance coverage and licenses. We will not delve too much into these. Other means to ensure you are dealing with reputable companies are:
The goal for any fraudulent business is to take money from you for little or no cost, and therefore the best way to avoid scams is to agree on a payment schedule with your contractor. First, never make the entire payment at the beginning as there is no guarantee that the organization will come back to complete the job. Also, only make the last payment once you are satisfied with the work. Though most companies will ask for a deposit to secure the construction materials, it should not exceed 20% of the entire budget and should only be paid once the elements are on site. Most contractors will agree to this.
Another common scam with materials and payment is whereby as a homeowner you pay for top grade items, only for the company to purchase lower quality materials and pocket the rest of the money. Check the materials once they are delivered to warrant you get what you paid for.
Most fly-by-night contractors don’t take the time to set up a working space. By verifying whether the companies you are considering have an address, you separate the credible ones from the swindlers. First, avoid companies which are from out of state. Odds are you will not be in a position to verify their address. Also, don’t take the institutions word for it, and make an effort to visit them and get a feel of what they are about.
Avoid special offers
As pointed out earlier, the top reason why most homeowners end up with failed retaining walls is that they opted for the cheapest option. Special offers and today-only discounts are another common retaining wall scam. Most swindlers use this to get you to sign the contract where they will change the terms later. You will end up paying more than you had anticipated. Also, there instances where contractors want to lure you into signing a contract without considering other bids. Often their proposals are higher, and their special discounts are a ploy.
So to prevent the organization from changing the terms without your consent, ensure you get a provision that warrants you are informed of any cost changes ahead of time.
Get it in writing
Finally, sign a contract. A contact safeguards you and the contractor. Therefore, ensure you sign one before work starts.
10 Questions to Ask your Retaining Wall Contractor
1. What is the projected cost?
It’s not unheard of for contractors to change the cost of a project halfway through. It’s best you have clear communication regarding the estimated value and your budget before work begins.
2. Are you certified as a segmental retaining wall installer?
The idea here is to ensure the company you hire is capable of professionally handling the task. Certified employees shows that they are dedicated to quality and education.
3. How long will the project take?
The idea here is to establish deadlines. You don’t want to have strangers on your property for awfully too long. Ensure you have set reasonable deadlines with your and put in measures to ensure that the contractor meets them. You can do this by charging him/her for every day the project is late.
4. Are you okay if I hire inspectors to check the wall as it proceeds?
The idea here is to ensure you get only quality work. Most homeowners report retaining walls failure despite paying top-dollar for the job. Monitoring and evaluation will ensure that wall is constructed appropriately at every stage.
5. Who is responsible for work permits?
Establishing who is responsible for the work permits is paramount. Most retaining walls will require construction permits more so if you are working close to the property boundary. Establish who will get the permits to avoid conflict with the authorities.
6. Can I see some of your work?
The idea here is to get a feel of the contractor’s work. Ask for references too that you can follow up. Ask why they hired the contractor and if they can hire her/him again.
7. For how may years have you been operational?
The number of years a company has been erecting retaining walls is a testament to their skills and experience. Many years in the industry doesn’t assure you of quality work, but you can be sure of streamlined services if you work with older companies.
8. Do you have any legal complaints filed against you?
The idea here is to establish how forthcoming the company is. An institution willing to be honest with their clients is one you can trust. Avoid businesses that are hesitant to provide this information.
9. Can you provide any guarantees?
If constructed appropriately, retaining walls shouldn’t last you less than seven years, and these are timber walls which are susceptible to rot and weather elements. Work only with contractors who are willing to guarantee their work.
10. Who will be my contact person?
Establish who will be you should reach out to in case of any concerns with the wall. Preferably the contact person should be the lead on your project.
We hope we have given you enough information to make an informed decision about your retaining wall. If you have any thoughts leave a comment below.