How much does it cost to repair a subfloor?

Reviewed by Adam Graham remodeling expert. Written by Fixr.com.

Subflooring is the layer of flooring under the surface level, providing extra support to the structure and an even flat surface to place your top-level flooring materials like vinyl, tiles, or wood planks. Subfloors are usually made of plywood, MDF, or another sheeted wood material, meaning that they can be damaged from various factors, including age, water exposure, and termite infestations. When this happens, it is recommended to fix them as soon as possible, which is best done by a professional.

The national average cost of professional subfloor repairs is between $250 and $750. Most homeowners pay around $500 to fix a 150 sq.ft. water-damaged section of plywood subflooring. At the low end, some people spend just $150 to patch a small hole in the subfloor. At the high end of the spectrum, it can cost as much as $2,000 to repair and reinforce large sections of a sagging subfloor.

Subfloor Repair Price

Subfloor Repair Cost per Square Foot

The average subfloor repair cost per square foot ranges between $2 and $10, with labor and materials included. The cost depends on the type of subfloor, the repair needed, and the solution required. For example, it may cost much more to repair a concrete subfloor and a simple plywood subfloor because the process of fixing and/or replacing concrete is much more labor-intensive than laying a sheet of new plywood.

Cost to Repair a Subfloor by Material

Subfloors can be made from a wide range of materials. Plywood and OSB are the most common subfloor materials and are usually the most affordable to repair. The materials are cheap, and most repairs are simple. Even replacing an entire sheet of subflooring (usually 4 x 8 feet) will be much cheaper than other materials. Some people choose new high-performance subfloor panels that offer premium comfort and stability but incur a higher repair cost because of the materials involved. In some instances, these panels may need to be replaced entirely instead of repaired. Concrete subflooring will usually be more costly to repair. Even simple cracks or concrete chipping could signify more serious damage or a need for more than simple crack repair. The table below lists the average cost per sq.ft. for subfloor repair based on the material, including all parts and labor.

Cost to Fix a Subfloor by Location

Subfloors are found in various locations, including the living room, bedroom, bathroom, and kitchen. The average price for fixing subfloors is between $250 and $8,000, but the prices are higher if it is hard-to-access, which often happens in rooms like bathrooms and kitchens. The table below shows common locations and the average repair prices for each.

Mobile Home Subfloor Repair

Homeowners pay between $250 and $900 to fix a mobile home subfloor. They can be difficult to access, and you have to be careful when removing flooring sections due to plumbing pipes and electricity wires. They are at risk of various issues like water damage and rot. Mobile home subfloors are the cheapest to repair because the space is smaller, and the materials are usually cheaper. It is best to work with a specialist who handles mobile home flooring.

Repair a Bedroom Subfloor

The cost to repair a bedroom subfloor is $300 to $700. The cost depends on the size of the repair, what needs to be fixed, and what material is used for the subflooring. If the top flooring has to be removed and/or replaced after the subfloor is repaired, this can increase the costs. Bedroom floors are less prone to regular damage, but things can still come up that require attention and repair. For example, there may be cracks or separation of the floor boards over time as the house settles, creating creaky spots and leaving the subfloors more exposed to potential danger. Buckling and warping of the subfloor may also occur over time and require repairs.

Repair a Bathroom Subfloor

The cost to fix a bathroom subfloor ranges between $300 and $950. Bathroom floors can have tiles and different materials and piping underneath the floor, so great levels of care and attention are required when making adjustments and repairs. There is also a high risk of water damage in the bathroom from the high moisture levels and possible leaks. You may also pay more if waterproof subflooring or other premium materials are installed to prevent future issues.

Kitchen Subfloor Repair

Fixing a kitchen subfloor averages $350 to $1,200. Like bathrooms, kitchens can have different flooring materials that may make it hard to access, leading to higher labor prices and more time required to fix common problems. There is also a higher-than-average risk of water damage in kitchens. Since many kitchens are tiled, if the seams are not secure or the grout is not properly installed, water can seep through the cracks or gaps and damage the subfloor, often unnoticed until the damage is severe.

Living Room Subfloor Repair

Repairing the subfloor in a living room costs $500 to $3,000. The cost depends on the flooring materials that need to be removed or replaced when accessing the subfloor damage and what damage is present. Subfloors in the living room are prone to sagging and sloping over time as the house settles. This may also be due to joists that are old and beginning to deteriorate, which could increase the repair cost. The size and nature of the repair determine the total cost. If the damage is severe enough, a section of flooring or the entire floor may need to be replaced, which will have an additional cost.

Basement Subfloor Repair

The average cost to repair a basement subfloor ranges from $1,000 to $8,000. This is usually more expensive because basement floors are typically made of concrete and require more extensive work to repair, depending on the type of damage. The cost depends on the size of the basement and whether the repairs are localized or cover the entire floor surface. Small repairs may be more affordable if addressed before they become too severe. The most common issue in basements is water damage, with cracks from settling and foundation issues coming in second. Water damage needs to be addressed immediately, and cracks can usually be filled for a simple repair. In some instances, cracks may signify bigger structural issues, so it is important to let the professionals assist with diagnosis and repair.

Cost to Repair a Subfloor by Problem

The cost to repair a subfloor ranges from $150 to $10,000, depending on its problem. Various issues can arise with subfloors. For example, it might develop holes that need to be patched or start sagging in certain areas. It might also suffer from joist problems, water damage, rot, or termites. The problem type impacts the repair prices because some issues are cheaper and easier to fix. The table below shows examples and average repair prices for each.

Repair a Hole in a Subfloor

Homeowners pay between $150 and $600 to professionally fix a small to medium-sized hole in the subfloor. Holes may appear from rot or impacts and accidents on the floor. The price mostly depends on the hole size and accessibility. Small holes can be filled or patched with putty or patching materials, but the damaged section may need to be removed and replaced for larger holes, including any flooring (tile, carpet, wood planks, etc).

Crack in a Subfloor

Expect to pay between $150 and $600 to fix a mid-size superficial crack in the subfloor. The prices are usually lower if you spot and fix cracks early. Cracks can appear from water damage, swelling, and changing temperatures. A contractor usually fills or patches cracks with putty or filler material to fix them. If the cracks are no longer superficial and have become structural, they may require more extensive repair at a higher cost.

Fix a Squeaky Subfloor

The price to fix a squeaky subfloor is between $200 and $1,000. There can be many causes for this. Some are cheaper to fix than others. Squeaky floors could be caused by uneven sections or water damage from spillage or excess humidity. The repair type depends on the problem’s cause. Fixing a squeaky subfloor can be as simple as putting shims in the gaps between the subfloor and the joists or beams. Suppose the squeaks are due to improper main floor installation. In that case, it may be necessary to remove and replace the entire floor to level and secure the materials to prevent future issues. Squeaks are just a symptom of a more serious problem and should be addressed promptly.

Repair Water-Damaged Subfloors

Water-damaged subfloors average $250 to $750 for fixes. Water can damage subfloors when left unchecked, so act fast if you spot signs of water damage. Usually, a contractor removes the damaged sections and replaces them with new ones. A sealant may also be needed to prevent future damage.

Rotted Subfloor Repair

It costs $250 to $1,000 to professionally fix a rotted section of the subfloor. The prices can be higher, depending on the extent of the rot and if it spread to surrounding areas. When rot is spotted early, it is cheaper to fix by removing the rotted sections, installing new materials, and applying a sealant to prevent further water damage.

Moldy Subfloor Repair

Homeowners pay between $350 and $1,300 to treat and remove mold in their subfloor, but prices can be significantly higher if it affects a large area. Mold can be a problem on subflooring layers exposed to excess moisture and heat, such as in bathrooms and kitchens. The flooring must be removed, and mold treatment solutions applied to the area to fix the issue.

Sagging Subfloor Repair

Fixing a sagging subfloor ranges from $400 to $2,000. The final price mostly depends on the size of the sagging issue. Sagging often occurs from weaknesses in the joists or damages from moisture. The joists may need to be reinforced, support columns or steel jacks might need to be installed, or other measures may be taken to lift the sagging subfloor.

Fix an Uneven Subfloor

Prices average $400 to $2,000 to fix an uneven subfloor. This problem is easy to identify because the floor does not feel straight or balanced in areas, and it may seem to dip or sag randomly. This may be solved by sistering or reinforcing the joints or installing supporting structures like jacks and columns to even it.

Termite Damage Subfloor Repair

Homeowners pay between $500 and $700 to fix subfloor termite damage. This can be one of the more expensive repair jobs for subfloors. Act fast if you notice signs of termite damage to prevent the issue from becoming worse. An exterminator must remove the termites, and a termite treatment is applied to prevent them from coming back. Damaged sections also need patching.

Subfloor Joist Damage Repair

You can expect to spend between $1,000 and $10,000 to repair damaged joists in your subfloor. The cost depends on what damage exists and how extensive it is. It will also depend on how many joists are affected. The joists run along the length of the floor to support the weight of the floor above, furniture, and people. These are essential to the integrity of the floor. When they are damaged from pressure or moisture exposure, they need to be repaired immediately to prevent further issues. A common repair method is sistering, which is when joists are reinforced with extra materials to enhance their support capabilities without the need for total replacement.

Cost to Repair a Subfloor by Solution

It costs between $150 and $1,200 to repair a subfloor based on the solution required. Professional contractors and specialists might use various methods to fix your subfloor. They might patch the affected areas for holes and cracks, while other types of damage might require other solutions, such as sealing or reinforcement. The table below shows common solutions and average prices for each.

Subfloor Patch

The average cost to patch a subfloor ranges from $150 to $600. Patching is a common repair method when it develops holes or gaps. Patching materials and kits can patch these holes to prevent water or dirt from entering and causing extra damage. This can be a very efficient method when dealing with minor superficial damages.

Subfloor Crack Filler

Homeowners pay $150 to $600 to fill cracks in their subfloor. When it develops a crack, a professional contractor usually uses filler material to fill in the crack and sand it down to be in line with the level. This is often a cheaper alternative to replacing the damaged section. Small cracks could become much more serious if they are not addressed immediately, so it is best to contact a professional as soon as cracks are noticed.

Subfloor Section Replacement

You will spend between $150 and $1,200 on replacing a section of subflooring, depending on the materials and what is being replaced as part of the damage repair. In some instances, a repair involves replacing a section of the subfloor and its related parts, such as if water damage is too extensive and cannot be simply cleaned up and fixed. This is an alternative to replacing the entire subfloor when only a part of it needs to be repaired or replaced.

Subfloor Sealing

To seal your subfloor, expect to pay between $250 and $700. Sealing is best done during the installation process, but it can be done afterward by removing the top layers of flooring to access it. It is helpful for protecting your subfloor from moisture damage and reducing the risk of expensive rot and water damage repair. This is typically seen in basements and with other concrete subfloor installations.

Reinforce a Subfloor

Subfloor reinforcement averages $300 to $1,000. Also known as “sistering,” reinforcement can be useful when the subfloor structure has been weakened from damaged joists or sagging sections. There are various methods of reinforcement, including sistering damaged joists or the installation of steel jacks to provide extra support underneath it. Additional plywood materials can also be attached around the joists to provide extra strength.

Subfloor Termite Treatment

If termites cause subfloor damage, you may spend between $300 and $1,200 on termite treatment to eradicate the infestation. After all, if you repair the damage but do not get rid of the pests, the damage will happen again and can quickly become more extensive than people realize. It is always best to consult a pest control expert when you find termite damage in the home.

Labor Cost to Repair a Subfloor

Labor costs for subfloor repairs typically range from $25 to $45 per hour. A wide range of factors impact the labor costs, such as the problem, repair method, time spent on the job, and accessibility. Jobs take from a few hours to several days, depending on the problem size and scale. Some contractors charge call-out fees of around $50 to visit your property and assess the damage. Others have minimum fees of $100 to $150 for repair jobs. They may also charge extra for travel fees if you live in a remote location.

It is best to have professionals perform any subfloor repairs that are needed. The floors of your home need to be in good working order, level, and installed correctly. Even if it seems like a small patch or crack repair that can be handled as a DIY project, it could be a sign of bigger issues and should always be inspected and repaired by someone experienced with subflooring repair and replacement.

Subfloor Inspection Cost

A subfloor inspection ranges between $100 and $400, depending on the property size. Since they can be difficult to access and hidden by other layers of flooring, most professionals do not offer specific inspections. Instead, they offer a general flooring inspection to look for signs of damage, such as uneven or sunken areas, strange smells, and squeaking sounds. They provide you with a full report of their findings and more closely investigate problem areas. This can spot problems early and have them fixed before they become more serious.

In some instances, the inspection fee may be waived if the same professional performs the repair work. An inspection is usually only required if you suspect that there are problems with your subfloor. However, a subfloor inspection may also be performed as part of an appraisal for refinancing or selling a home, in which case the owner of the home would pay all inspection costs. Ask about the fees and how they factor into your total repair cost.

Cost to Repair vs Replace Subfloor

You will spend $250 to $750 on repairing a subfloor. However, it can cost $600 to $2,400 to replace it completely. Subfloors do not often need replacing and last for decades without major problems, but it might be better to replace them if they are seriously damaged, very old, or defective. If the subfloor has been subject to water damage, mold and mildew growth, or related issues, a replacement might be the better option to remove the potential hazards completely. If your subfloor is heavily damaged, you might hesitate between fixing or replacing it. Talk to a professional to determine the best course of action for the integrity of the floor, the safety of your family, and your budget. The table below shows a comparison of the costs for each project.

Enhancement and Improvement Costs

Clean a Subfloor

Cleaning subfloors usually ranges between $100 and $500, depending on the flooring size. This can be an important process when installing new top layers of flooring, and it can be a good idea to check and clean the subfloor before adding a new layer to prevent dust and dirt build-up. Homeowners can also save money by cleaning subfloors with vacuum cleaners and homemade cleaning solutions.

Additional Considerations and Costs

• Permit. Permits are not usually required for subfloor repairs and replacements, but it is still wise to check with your local building authority.
• DIY. You can carry out some basic maintenance and repairs if you have experience working with floors, but most jobs should be left to the pros.
• Added value. Subfloors in good condition do not necessarily add value to a property but can be mentioned as an extra incentive for prospective buyers.
• Lifespan. Subfloors can last as long as a house with regular maintenance and care, but they might only last around 30 years if they are defective or damaged.
• RV subfloor repair. If you have sagging floors or other damage in your RV, you may need to contact an RV specialist to handle the subfloor repair. This typically costs between $600 and $6,000, depending on whether repairs are possible or if a full replacement is needed.