How Much Does Slab Leak Repair Cost?

• Typical Range: $630 to $4,400
• National Average: $2,290

When plumbing leaks happen beneath a home’s concrete slab foundation, it’s important that homeowners address the problem as soon as possible. If the pipes that are running under the foundation corrode or shifting soil makes them leak, significant water damage can occur inside the home. Depending on the type of concrete slab and the location of the slab leak, plumbing leak repairs can be made using various repair methods. According to Angi and HomeAdvisor, the average cost of slab leak repair ranges from $630 to $4,400, with the national average at $2,290. A slab leak that is in a difficult-to-access spot can result in higher costs, since labor rates will be higher for a more complex job. The final cost for slab leak repair depends on the type of repairs that are needed to stop the leak and the type of fix that is needed for the concrete slab after the water leak repair has been made.

Since slab leaks occur under a concrete slab foundation, they are difficult to detect and problematic to prevent. Slab foundations are built on top of a layer of gravel that’s placed on top of piping and sewer lines. Slab leaks can happen in both sewer and water pipes, and the slab leak signs for each type are different. Homeowners who notice an increase in their water bills, wet spots or warm areas on floors, mold growth, or the sound of running water may have a leaking water pipe beneath the slab foundation. If a broken sewer line is to blame, some signs can be soil that is washing away from the foundation, elevated areas on the floor, or cracks in the foundation. Monitoring a home’s foundation and keeping a careful eye on any changes that may occur to the flooring can help homeowners discover slab leaks before they cause significant damage.

This guide will break down the factors that affect slab leak repair cost, the different types of repairs, the signs that repairs are needed, some important questions to ask contractors, and some frequently asked questions about slab leaks and foundation repair.

Factors in Calculating Slab Leak Repair Cost

Calculating slab leak repair costs depends on several important factors. Repair costs can differ from the national average due to method of leak detection, leak location, repair method, local labor costs, leak accessibility, and geographic location.

Leak Detection

Slab leak detection costs $280 on average, but the pricing can range from $150 to $400. If a homeowner thinks they might have a slab leak, it’s recommended they call a plumber as soon as possible. A plumber can look for leaks by testing the water pressure in the area, looking for signs of excess water in the soil and landscaping surrounding the slab foundation, and inspecting the foundation for signs of moisture or cracks. Some slab leak signs may be more obvious, while others require more time-intensive processes, such as drilling into the foundation or inserting a camera into water pipes and drain lines.

Some signs of a slab leak include cracks in the foundation, unpleasant odors, mold and mildew growth, increased water bills, low water pressure, the sound of running water, and the presence of standing water. Each of these red flags is discussed below.

Leak Location

The cost of pipe leak repair is influenced by the leak location. If the leak is difficult to access, it will cost considerably more than an easy-to-reach leak. Professional plumbers know how to find a slab leak. They use special equipment to find exactly where the leak is located and determine the extent of the required repair.

Repair Method

The pricing to repair a slab leak can vary from the national average of $2,290, since there are many different ways to repair a slab leak. Some methods of repair are specific to the type of leak or pipe, while others work better depending on the location of the leak. The cost of each repair method hinges on soil conditions, foundation slab thickness, pipe type, and size of the leak. Some of the common repair methods include total slab replacement; slab sealing, patching, or breaking; under-house tunneling; under-slab plumbing repair; water line or water main repair; broken pipe repair; pipe rerouting; pipe lining; and leaking pipe repair. Each of these repair methods is discussed below.

Labor

Plumbers who repair slab leaks typically charge between $45 and $200 per hour for their services, with the average hourly cost running between $75 and $130. Some repairs can be priced by the foot, which includes the cost of materials and labor. Other types of repairs may have individual material and labor fees. An inspection generally takes 1 to 3 hours, and a slab leak repair can take anywhere from 2 hours to 3 days, depending on the severity, which means the span of labor costs can range from $90 to $4,800.

Accessibility

In some extreme cases, it may be necessary to tear up large sections of the flooring inside the home and dig down into the foundation to make slab leak repairs. Each slab leak is unique and will have its own issues with accessibility. When the leak is difficult to access, the price of repairs will go up due to the extra time needed to fix the leak.

Geographic Location

Concrete slab foundation leaks are more common in areas that experience earthquakes or for those who live near a fault line and experience soil shifts. Homeowners in these areas may be more conscious of foundation problems and slab leaks than those who do not live in earthquake-prone locations. Being knowledgeable about the risks associated with the local geography can tune in homeowners to potential issues. It’s important to note that contractors and plumbers will typically charge more for labor in densely populated urban areas with a higher cost of living, compared to those in more rural locations.

Additional Costs and Considerations

When budgeting for slab leak repair cost, homeowners may find it helpful to have any information regarding additional costs and considerations that can increase the price of the repair project. These can include excavation, foundation repair, water damage repair, subfloor repair or replacement, and permit fees.

Excavation

If excavation is required to remove landscaping and the soil surrounding the foundation, the project will incur additional charges.

Foundation Repair

After the leaks are repaired, the foundation will need to be fixed. Foundation repair can run around $2,100 at the low end to $7,300 or more at the high end. Homeowners will want to keep in mind that slab leaks require that the plumber dig through the foundation to access the issue. Foundation repair cost can be an expensive but necessary part of the process and will increase the overall cost of the repair project.

Water Damage Repair

It’s common for slab leaks to remain unnoticed until there are obvious signs. Leaks that go unobserved for an extended period of time can cause extensive water damage to the concrete slab, subfloor, plumbing, flooring, and walls. Water damage repair can cost from $500 to $15,000, depending on the extent of the damage.

Subfloor Repair or Replacement

If there is a wood subfloor installed over the top of the concrete foundation slab, a leak will likely cause damage to the subfloor. The cost to replace a subfloor due to water damage runs from $500 to $1,000. A wooden subfloor that sustains water damage can rot, warp, or experience mold and mildew growth. Removing the subfloor and ensuring the area is completely dry before installing a new one are the only ways to fix the problem.

Permits

Permits are not typically required for slab leak repairs, but it’s recommended that homeowners check their local regulations and ask the plumber before beginning repairs. A local professional will likely know whether a permit is needed, and if so, how to procure one before starting the repair project.

Types of Slab Leak Repair

Depending on the type of leak, location of the leak, slab thickness, type of pipe, and soil conditions, a plumber may give homeowners a few options for repairs. Some leaks require one specific way to remedy the issue, and each type of slab leak repair has its own costs and considerations. The following are different types of slab leak repairs and their average prices.

Total Slab Replacement

If the concrete foundation slab has extensive damage and is beyond repair, replacing it is the only option. A total slab replacement costs from $3,600 to $8,000, or about $6 per square foot. Sometimes it’s necessary to dig up a large section of the foundation when making a slab leak repair. If only a portion of the foundation needs to be replaced, the overall price of the project will be lower. While not every slab leak repair will require a complete replacement, it’s helpful for many homeowners to know the cost of a new concrete pour.

Slab Sealing

Since concrete is a porous material, it’s important to seal the surface of the foundation slab after the leak repairs. If the concrete absorbs water, the moisture can lead to serious issues, such as cracking, mold growth, and efflorescence, which occurs when vapor travels through the concrete and brings soluble salts to the top of the slab. When the concrete slab is sealed, it blocks the material from absorbing water. Slab sealing costs range from $100 to $200.

Slab Patching

Slab leaks can cause cracks in the concrete foundation; patching can seal the cracks and strengthen the slab. If holes are drilled into the slab to repair a pipe leak, those areas will also need to be patched. Slab patching costs run between $250 and $800.

Slab Breaking

Slab breaking is one way to reach a leaking pipe. If it is not possible to tunnel under the foundation or use a trenchless sleeve to access the leak, breaking the slab may be the only option. The exact amount of slab that needs to be broken is influenced by the size of the leak. The flooring and subflooring on top of the concrete slab will need to be removed before the slab is broken. If the flooring is in good shape and doesn’t have water damage, it can be reused and reinstalled after the concrete slab has been repaired. Breaking a concrete slab costs from $500 to $3,000.

Under-House Tunneling

Under-house tunneling involves excavating the soil from under the concrete foundation slab, removing any water, repairing the pipe, and refilling the tunnel. As one of the most noninvasive repair methods, it’s best used in areas with a stable and supportive soil base and not in locations that experience shifting soil. Under-house tunneling costs between $900 and $2,000.

Under-Slab Plumbing Repair

Under-slab plumbing repair ranges from $500 to $4,000, depending on the degree of the damage, the location, and the type of pipe. If the pipe can be easily bonded together, it will be the most budget-friendly type of repair, but other types of damage require sections of the pipe to be replaced, which leads to higher costs. Under-slab repairs are common with slab leaks. They’re usually caused by improper pipe installation or broken pipes. The price of the repair doesn’t include the cost of accessing the leak, which can be done by opening the slab or tunneling.

Water Line or Water Main Repair

The average cost to repair a leaky water line is $840. The cost to repair a water main can be as low as $150 or as high as $3,000, with the national average ranging between $330 and $1,360.

Broken Pipe Repair

Repairing a broken pipe underneath a foundation slab runs from $200 to $2,000. The large price range is due to leak detection costs, the individual method of repair, the type of pipe, and the extent of the damage.

Pipe Rerouting

How much does a slab leak reroute cost? Pipe rerouting from a concrete slab foundation ranges from $1,500 to $15,000. Rerouting the pipes is a good option when there is more than one problem under the slab. The process involves capping off the damaged pipes and installing new ones. Depending on the damage, homeowners may be advised to have the pipes rerouted through the attic or the walls of the home. Rerouting can provide a permanent solution to recurring pipe issues caused by excessive moisture or shifting soil.

Pipe Lining

Lining a pipe helps fend off water leaks from happening in the future. Depending on the pipe length, pipe lining costs from $500 to $2,000. One of the most cost-effective ways to remedy a slab leak is trenchless pipe lining, or trenchless pipe repair. Trenchless pipe lining involves less digging and less time spent on the repair. Without the large amount of excavation that is typically needed to dig up a pipe, trenchless lining costs less. With this repair method, a liner is inserted into the damaged pipe to restore its strength and prevent leaking. Because this repair method is typically priced by the linear foot, the longer the pipe, the more expensive the repair.

Leaking Pipe Repair

If a leaking pipe needs to be repaired, the cost can range from $150 to $350. If the source of the leak is difficult to locate, the price of the repair can escalate quickly due to the increased labor and need for additional leak detection equipment.

Do I Need Slab Leak Repair?

There are many red flags that indicate there is a slab leak under a home. If homeowners discover any of the following issues, they will want to call a plumber as soon as possible for slab leak detection testing.

Foundation Cracks

Water leaking underneath a concrete foundation slab can cause cracks due to the pressure the excess water creates. Over time, the leaking water can damage the foundation and the interior of the home. While concrete slab foundations may crack for other reasons, it’s always a good idea to get a slab leak assessment from a plumber.

Unpleasant Odor

A slab leak can cause mold and mildew growth under the flooring of a home. If homeowners detect a damp, musty smell in the rooms that are above the foundation slab, there may be a water leak. The absence of a vapor barrier may make the unpleasant odor more apparent.

Mold and Mildew

The more water that seeps through the concrete foundation slab, the more likely the water will absorb into the flooring and the drywall. If there is evidence of mold and mildew growth on the floor or walls above the foundation slab, it could signal a slab leak. Wet spots or soggy, damp areas at the base of the walls or throughout the floor are also signs to call a plumber.

Higher Water Bills

If the water bill is getting higher without increased water usage, it’s a sign that there is a water leak somewhere in the home. If there’s no noticeable leak, homeowners are advised to call in an expert to assess the issue and check for a slab leak.

Low Water Pressure

Pipes in proper working condition will have consistent pressure, but if there’s a leak, the water pressure in the house will drop. Low water pressure accompanied by a higher than usual water bill typically indicates a water leak.

Running Water Sounds

If a water leak under the foundation slab is large, there may be the sound of running water in rooms directly above the concrete slab. Homeowners who hear this sound when no faucets or appliances are in use are advised to call a plumber to investigate.

Standing Water

Water leaking out of pipes under a concrete foundation slab will run to a lower area and pool, typically near the foundation. If there are unexplainable puddles of water around the house or in the lawn, or if landscaping close to the foundation looks as if it’s getting more water than other plants, there could be a water leak.

Slab Leak Repair: DIY vs. Hiring a Professional 

While it may be tempting for a homeowner to tackle a slab leak repair on their own to save money, they could cause more problems in the process. A slab leak repair is a job that requires an experienced professional who has the knowledge and equipment to make the needed repairs, and the cost to hire a plumber or other professional for this project is well worth it. The average homeowner will not have the training or the specialized tools and equipment that are needed to fix an under-slab water leak. Further, some insurance companies will not cover a slab leak repair made by the homeowner, since many DIY repairs cause more damage. For the safest and most cost-effective solution for a slab leak repair, it’s recommended that homeowners call one of the best plumbing services to handle the project.

How to Save Money on Slab Leak Repair Cost

Slab leak repairs are a potential expense for homeowners with a concrete foundation slab, but preparing for the expense can help take the sting out of the project total. Knowing the possible additional costs that can add up during the project can help homeowners budget for a slab repair. While a slab leak repair can be expensive, not fixing it in a timely manner can result in even more expenses. One way to save money is to use the cheapest materials and opt for minimal repairs, but there are other ways to save money without compromising on quality.

• Get multiple estimates. Shop around and get at least three estimates from reputable plumbers in your area to find a price that works with your budget.
• Don’t put it off. Waiting to make repairs on a slab leak will result in even more costs due to the damage a leak can cause.
• Consider the insurance policy. Some insurance companies will not cover slab leaks if the repairs are postponed and further damage the concrete slab foundation.
• Learn about the health impact. Water leaks can cause mold and mildew growth in the home. A mold-infested house can cause respiratory illnesses and trigger debilitating asthma attacks. Quickly addressing a slab leak can save money on health-care costs.
• Recognize the signs. Knowing the signs of a concrete foundation slab leak can help homeowners detect a problem early, before extensive damage is done to the foundation, flooring, and walls of the home. This can help you save money on additional costly repairs.
• Ask about discounts. Some plumbing companies may have seasonal discounts or promotional offers to help you save money on the slab leak repair.

Questions to Ask About Slab Leak Repair

Knowing what to expect during a slab leak repair project can be helpful for many homeowners when the problem arises. Asking an experienced plumber the right questions can minimize miscommunication, save money, and get homeowners the desired results. What follows are some questions to ask about slab leaks and the repair process.

• What is a slab leak?
• How do I know if my home has a foundation slab leak?
• Are you licensed and insured?
• Do you have a service agreement?
• What types of warranties or guarantees do you offer?
• Do you have references?
• How long has your company been in business?
• How much experience do your employees have with slab repairs?
• Do you hire subcontractors for slab leak or foundation repairs?
• Do I need to pay for a permit for a foundation slab leak repair?
• Will you have to dig up the inside of my house or the yard to find a slab leak?
• How do you protect the landscaping around the house during the slab leak repair?
• Does my municipality require an engineer’s report for a slab leak or foundation repair?
• How long will it take to repair a slab leak?
• How much will it cost to repair a concrete foundation slab leak?
• Do you provide free estimates?
• Do you offer any discounts or have promotional offers?
• Will my homeowner’s insurance cover slab leak repairs?
• What type of slab leak repair do you recommend for my home?
• Do you test the plumbing under the home after the repair?
• How do you minimize the risk of the foundation settling after repairs?
• When can you start the repair job?
• How can I leave a review of your services?

FAQs

Before deciding on a plumber for a slab leak repair, homeowners can benefit from having all the information they need regarding the cost of the project. The following are some frequently asked questions about slab leaks and the repair process.

Q. Is a slab leak covered by insurance?

One of the most common questions homeowners ask when they discover they have a concrete foundation slab leak is if it’s covered by their insurance policy. Home warranties typically do not cover water damage, and while many insurance companies may help pay for a foundation slab leak repair, there can be occasions where the slab leak insurance coverage doesn’t protect against the entire cost. If the insurance policy covers wind, fire, falling objects, or explosions, and one of those perils causes plumbing issues that result in a slab leak, the leak repairs will likely be covered. Certain types of insurance coverage, such as dwelling or personal property coverage, will help pay to make the needed repairs to the plumbing, foundation, or home due to a slab leak. Homeowners will want to keep in mind that they will typically need to pay a deductible before the insurance company provides assistance for the needed repairs.

Some causes of a concrete foundation slab leak, such as old plumbing or tree roots inside the pipes, are typically not covered by a homeowner’s insurance policy. There is the option to include service line coverage in a policy, so if that’s available, it may help cover the repair costs. Homeowners can check with their insurance agent and review their policy to see whether slab leak repairs are covered for their home.

Q. Can a cracked slab be repaired?

Yes, cracked foundation slabs can be repaired. Often, people think that filling the surface of a crack with an epoxy-based solution will fix the problem, but that only helps the cosmetic issue. Cracks in a concrete foundation slab can appear for various reasons, such as ground movement, insufficient support, settling, or a bad concrete mix. A more permanent fix to strengthen and reinforce the area surrounding the crack can help against excess moisture or radon gas seepage through the crack. Fixing the crack and any weak spots in the surrounding area can mitigate mold and mildew growth as well as serious health issues from radon gas within the home.

Q. How can you tell where a water leak is coming from?

Since water leaks can quickly damage a home, it’s important to detect a water leak and find out where it’s coming from as soon as possible. The following tips on how to find a water leak will help homeowners determine the source of the leak and ways to stop it.

• Check the water bill. If the bill is higher than normal, it could be a sign of a water leak.
• Look for puddles. If you see patches of standing water in the lawn or notice areas of landscaping that grow at a faster rate than usual, there may be a leak underground that needs to be addressed.
• Monitor the water meter. Many homeowners look at their water meter to determine if they have a water leak. If all appliances are turned off and no faucets are running but the numbers on the water meter are increasing, there’s likely a water leak.
• Check the fixtures and appliances. Look under the sinks, around appliances that use water, and around the toilets and water heater. If you discover standing water, turn off the water supply and call a plumber.
• Pay attention to the signs of water leaks. Do you smell a musty odor, notice wall discoloration, or hear the sound of running water? These can be signs of a water leak.
• Install a leak detector. Water leak detectors will emit a loud alarm when they detect a water leak. These detectors are beneficial in areas of the home that aren’t frequently used, such as an unfinished basement that houses a water heater. Detecting a leak early can save homeowners money on repair costs if the leak goes undetected.

Q. How common are slab leaks?

Slab leaks are common in older homes that are built on a concrete foundation slab. Experienced and trained plumbers can discover slab leaks with their professional assessment of the area.

Q. Can a slab leak cause foundation problems?

A slab leak can cause serious foundation problems if left unrepaired. Water damage can weaken the structural integrity of a concrete foundation slab and cause it to crack, shift, or collapse.

Q. How serious is a slab leak?

A slab leak is a very serious issue and needs to be fixed as soon as possible. In addition to driving up the water bill, a slab leak can damage the concrete foundation slab and cause it to crack, shift, or buckle. Foundation damage can cause issues with the flooring and walls and may even cause parts of the house to collapse.

Sources: Angi (1 and 2), HomeAdvisor, Fixr