If you think you need foundation repairs completed and have been doing research on the different repair methods, you’ve probably come across helical piers. Installing helical piers — a form of underpinning — is a popular and often permanent foundation repair solution for a variety of issues. It can be quite expensive, but it’s considered cost-effective due to its permanence.
In this guide to helical piers, we’ll be discussing what these piers are, how much they cost, and some factors that affect the price of the repair. We’ll also explain how helical piers differ from other foundation supports and when these piers are the best option for your home.
What Are Helical Piers?
Helical piers — also called helical piles or screw piles — are aform of foundation underpinning, meaning they are supports that get installed beneath a foundation to provide additional support.
Helical piers are usually shorter than other types of foundation piers, and they have helices on them, making each resemble a large screw.
The installation process involves either excavating around the foundation or drilling through it in the case of aconcrete slab foundation, screwing the helix into the ground, and affixing it to the foundation to provide support. The helices add surface area that rests on load-bearing soil to prevent it from sinking into the ground.
Since the helices grip the ground under your foundation, they don’t need to be terribly long — like steel piers that can reach down to bedrock up to around 200 feet. However, they are usually more expensive than other supports.
How Much Do Helical Piers Cost?
The average cost for a helical pier and professional installation is around $3,000. Most homeowners need between five and ten piers installed, although this number can increase dramatically based on the square footage of your home.
At an average cost of $3,000 per pier, the total average cost for helical pier installation is between $15,000 and $30,000.
The table below provides a quick look at the cost of helical piers based on the square footage of your home.
|500 to 1,000 sq ft||1,000 to 1,500 sq ft||1,500 to 2,000 sq ft||2,000 to 2,500 sq ft||2,500 to 3,000 sq ft||3,000+ sq ft|
|Expected # of Piers Needed||3||5||7||9||10 to 12||12+|
|Expected Cost||$9,000||$15,000||$21,000||$28,000||$30,000 to $3,6000||$36,000+|
Helical Pier Parts Cost
While the total cost to install a helical pier hovers around $3,000, only about half of that total is for the helical pier itself.
The piers are usually around 20 feet long to extend below the frost line and the area of the soil where moisture content changes rapidly in response to the weather. At a typical cost of around $75 to $100 per linear foot, that brings the total material cost per pier to between $1,500 and $2,000.
Helical Pier Installation Cost
The remainder of the $3,000 per pier is for the installation and labor. The process of installing a helical pier depends on your foundation style and a few other factors, but the house is usually supported using hydraulic jacks while the piers are driven into the ground. The tops of the piers are then affixed to the foundation using structural bolts.
Since the process involves excavation and the use of heavy machinery to drive in the piers, you’re looking at anywhere between $1,000 and $1,500 per pier for the labor.
Cost Factors to Consider
The total cost to install helical piers varies so much for a few reasons. The table below provides a quick look at some of the things that can affect your pricing and how the cost is determined. We’ll discuss these cost factors in greater detail in the sections below.
|Number of Piers Needed||Average Total Project Cost|
|Extent of the Damage||Average Total Project Cost|
|Soil Conditions||Average Total Project Cost|
|Landscaping Features Nearby||Average Total Project Cost|
Number of Piers Needed
Helical pier installation is almost always billed based on the number of piers you need, with an average cost of around $3,000 per pier. Therefore, each additional pier you need — whether it’s needed because of the extent of the damage, the size of the structure, or the weight of the structure above — will add around $3,000 to your total. As you can imagine, the total costs can quickly add up.
Extent of the Damage
The number of piers you need is often based on the extent of the damage. Minor damage to just a portion of your foundation may only require a few piers to prevent further foundation movement or settling. Moderate damage that needs structural stabilization will require more, and severe damage that puts your entire structure in danger will need the most.
If you’ve noticedfoundation damage warning signsthat suggest severe damage, you can expect your costs to be closer to the $30,000 mark.
The soil conditions can affect the cost of helical pier installation in two ways.
First, the issues with the soil movement are usually what require underpinning in the first place. Since sandy soil doesn’t expand or contract much, the risk of ongoing issues is likely low unless you have drainage problems that are causing erosion under your home. Loamy soil is a bit more expansive and might need additional piers.Clayey soil is the most expansiveand will often need the most piers to fix the issue and prevent future foundation problems from occurring.
Second, clayey soil is significantly harder to drill piers into, so your foundation repair professionals might need additional equipment or more time to get the piers into the ground. This should only have a marginal effect on your total foundation repair costs.
Finally, helical piers often require excavation around your home where the foundation settling has taken place. This process is expensive as it is, but it can be complicated by landscaping features, including decks, patios, pergolas, and walkways. If your repair specialist needs to remove the landscaping feature to access the area and reinstall it afterward, this will usually add to your total price.
Helical Piers vs Other Foundation Supports
Helical piers are a popular foundation solution for certain design loads, but they are far from the only option. In the table below and the following sections, we’ll discuss how installing helical piers compares to placing other foundational supports in price, effectiveness, and the situation in which each is used.
|Helical Piers||Steel Piers||Concrete Piers||Straight-Shaft End-Bearing Piers|
|Average Installation Cost Per Pier||$3,000||$1,500||$1,000||$2,000|
|Average Total Installation Cost||$30,000||$10,000||$5,000||$20,000|
|Best For||Areas where the bedrock is deeper than 200 feet; areas with sandy soil||Areas where the bedrock is within 200 feet of the surface||Lightweight applications, like patios and garage floors||For homes where unstable soil is found directly underneath|
Helical Piers vs Steel Piers
Helical piers differ from steel push piers in two main ways.
First, helical piles are much shorter — usually around 20 feet long — while push piers can be up to 200 feet long. The length difference is due to where these piers divert loads. Helical piers add support via the helices on the steel shaft, while push piers reach down to the bedrock to provide support.
Second, helical piers are best for areas where the bedrock is very deep — deeper than 200 feet — or where the soil is sandy and friction piers cannot be used. Push piers are best for areas where the bedrock is close to the surface.
Both piers provide a permanent solution to a sinking foundation system.
Helical Piers vs Concrete Piers
Helical piers are used more often for structural support — for an entire home — than concrete piers — which are more commonly used for lightweight applications, like patios and garage floors.
Concrete piers and helical piers both provide permanent solutions to sinking concrete, but helical piers can support far more weight than concrete piles. Due to the difference in the quality of these options, helical piers are significantly more expensive in most cases.
Helical Piers vs Straight-Shaft End-Bearing Piers
Helical piers are usually used in areas where the soil is supportive but has issues with erosion or expansion and contraction. Straight-shaft end-bearing piers are more often used when the soil below an existing foundation — or below new construction — will not provide the support needed for the structure above.
Frequently Asked Questions
How much do helical piers cost to install?
The average installation cost per helical pier is around $3,000, which includes materials and labor costs. Most homeowners need between eight and ten helical piers, which brings the average total installation cost to between $24,000 and $30,000.
Are helical piers expensive?
Helical piers are the most complicated type of foundation pier to manufacture and install, so they come with the highest per-pier cost of any of the options. However, helical piers work in most situations, and they provide a permanent solution for many foundation issues. They are sometimes the only option available, depending on the type of soil on your property.
In addition to the cost of helical pier installation, you might need to pay for a structural engineer’s inspection or a geotechnical report to confirm a helical pier system will suffice.
Are helical piers cheaper than concrete?
Helical piers are more expensive than concrete piers, and they’re used for different purposes. Helical piers are mostly used to provide support for entire structures, while concrete piers are used for things like patios and walkways that don’t have significant weight above.
Helical piles are also usually more expensive thanlifting your hometo pour a new foundation, but they often provide a more permanent solution.
How much do helical piers weigh?
A typical 20-foot helical pier will weigh approximately 130 pounds. Each pier is usually rated with a load capacity ofaround 500 tons or more.