(OSB subfloor without junk removal)
(advanced Tyroc subfloor over a concrete slab)
Cost to replace subfloor varies greatly by region (and even by zip code).
Get free estimates from flooring contractors in your city.
The average cost to replace subfloor is $1,500 - $1,650.
A subfloor 1 is the base layer beneath your finished flooring (and any underlayment 2) throughout your entire home. It is the part of the floor that you cannot see, attached to the joists, and it is the most important part of your floor since it holds up not only finished flooring, but everything you put in your home, from people to furniture and appliances. Cosmetic finished flooring, or “top flooring” such as carpet, hardwood, tile, or laminate, all sit on top of the subfloor, making it easy to change out your visible floors without changing any infrastructure.
Replacing a subfloor requires all floor layers to be removed first. Since this is the bottom-most layer, it is a labor-intensive job. The average price to replace the subfloor in a 300 square foot room is $1,500-1,650.
After years of wear and tear, a disaster, or any kind of major trauma to your floors, a subfloor can show signs of damage and need to be replaced. You’ll know your subfloor needs to be replaced when you see certain signs of damage such as uneven flooring, sunken areas, loud squeaky floorboards when you apply pressure, or the floor bouncing or shifting as you walk across it. Other signs of damage include hardwood floors cupping or separating from each other, or linoleum 3, often found in kitchens, bubbling or buckling. Any floors showing weak spots or cracks could have damage on the subfloor.
In a bathroom, a loose toilet or cracked tiles is a sign of subfloor damage. Even a room that smells musty could be trying to tell you that your floor boards need to be replaced. Sometimes the joists also need to be replaced with the floorboards, if the damage extends that far.
A subfloor’s main duty is to add support to the main floor material. When this stops happening due to damage, warping, weakening, or softening, it creates a dangerous living situation.
A subfloor needs to be sound and in good shape to hold the weight of everything in your home for a long time. But there are many things that can cause damage to subfloors.
Water damage is one of the biggest disruptors to your subfloor. Water damage occurs if there is a flood, excessive humidity, or leaks in household items like washers, toilets, or sinks. A humid, damp, mildewy basement can also cause damage to the subfloor. When water isn’t cleaned up and dried properly, floor boards can warp and mold or mildew can grow. Both of these issues are dangerous to the people living there.
Leaks in plumbing can either be a large, known leak or a slow, unseen leak that causes damage over time. Both will weaken the subfloor boards and leave room for mold growth and warping. If a heavy item such as a vanity or bathtub sits over this area on the floor it could fall through, leaving you with at least a giant mess, or at the worst a dangerous situation. Make sure to hire the services of a plumber before replacing the subfloor.
On top of water damage and leaks, pests can also cause damage to subfloors. Wood-eating pets such as termites and carpenter ants eat away at the floor leaving holes and soft spots. Powderpost beetles like moist soft wood to bore into. These pets love wood flooring and can cause structural damage to your property.
A crack in the home’s exterior or on the subfloor itself is a sign the floor needs replacing. Cracks weaken the floor and also allow moisture to enter the material. In a new home, settling can also cause damage to a subfloor.
Traditional subfloor materials include wood planks, plywood, oriented strand board (OSB) more commonly known as particle board, and concrete slab 6. Concrete slabs differ from wood subfloors in that they don’t require joists to hold them up as they are one continuous concrete slab.
Wood planks was the traditional subfloor material used before the mid-twentieth century. They are rarely used in subfloor replacements today. Typically made from softwood such as pine or fir, over time nails loosen and floor boards separate, causing squeaky floors. They are also prone to moisture. Occasionally in a remodel other materials are added on top of the plank to strengthen it without removing it. Wood plank flooring can be repaired with plywood, replaced with plywood or OCB, or have plywood installed on top of it leaving it intact.
Material | Characteristics | Price |
---|---|---|
OSB | Similar to plywood, but cheaper Compressed pieces of wood rather than planks Environmentally friendly Prone to moisture Shouldn’t be used in mobile homes or areas without vapor barriers 7 May need replacing more often than concrete or plywood Contains formaldehyde in the glue, which, if not sealed, can cause allergy-like symptoms from exposure. | $0.60-$1.15/sq.ft. |
Plywood | Comes in ½”, ⅝”, and ¾” tongue and groove options Thicker plywood works better for hardwood and tile floors Thinner options are better for linoleum and carpet More expensive than other types Longer lifespan | $1.05-$1.20/sq.ft. |
Concrete Slab | Hard, solid, durable Most common subfloor in basements Smooth flooring that isn’t prone to separating or settling Prone to moisture An underlayment is needed Maintains coldness | $2.50-$4.00/sq.ft. |
Today there is advanced subflooring beyond just plywood and OSB. Engineered subflooring materials are created with your environment in mind. Able to withstand moisture, they have their own moisture barriers built in. They also provide insulation, sometimes eliminating the need for underlayment. Engineered subfloors lay on top of concrete slabs rather than directly on joists. They are designed for high moisture areas such as basements. They look like rubber mats on top of OSB boards or rolls.
Material | Characteristics | Cost |
---|---|---|
Delta-FL | Comes in rolls rather than panels Moisture barrier without particle board attached to it Prevents mold and mildew smell Keeps floors warmer Easier to install than panels | $0.63/sq.ft. |
DRIcore system | ¾” thick, 2’ x 2’ wide panels Perfect for basements or other high moisture areas Easy to install Creates insulation between concrete and the finish flooring Supports up to 3,000 lbs per square foot | $1.75/sq.ft. |
Barricade | 2’ x 2’ panels. Raises finished floor temps by 10 degrees Supports up to 3,000 lbs per square foot Dampens sound making floor quieter | $1.94/sq.ft. |
Tyroc | Subfloor and underlayment combined Recycled rubber bottom layer combined with plastic and Magnesium Oxide top layer board, which prevents mold and mildew growth Use under any finished flooring from tile to laminate to carpet Floating system doesn’t require screws or glue to secure to a concrete slab | $2.70/sq.ft. |
Warmboard | Made with thick aluminum and wood Curved channels in the boards specifically for radiant heat tubing It comes in plywood and OSB options More expensive than other subfloors | $7/sq.ft. |
* We selected a variety of brands to improve and clarify the information contained in this cost guide. We do not receive any monetary compensation from these companies.
Replacing a subfloor is a labor-intensive job that requires special equipment and training. While you may be able to repair sections of a subfloor yourself, when replacing the entire floor, you should hire a professional. A pro does this every day. They know what to look for with damage, how to prevent damage in the future and the right way to install a sound, solid subfloor that will last the lifetime of your house.
Replacing a small portion of subfloor can be quick and easy for a professional, however replacing an entire floor will take much longer, anywhere from 8-24 hours. In order to replace the subfloor, the finished floor needs to be removed first. If there is an underlayment that will also be removed. Once the subfloor is visible, the professional will pull that up. At this time the joists will also be inspected for damage. If any joists are damaged they will be replaced first. Depending on the material used, the professionals will glue or screw down the new subfloor. They will then place down a new underlayment, if necessary (for example, a carpet pad), or a vapor barrier to prevent moisture, before putting back the old or installing a new floor. If any appliances or furniture needed to be moved before starting the project, the professional will put them back.
Labor costs to replace a subfloor vary between $30 and $100 an hour depending on your location and the difficulty of the job. Floor specialists in major cities tend to cost more than those who operate in rural or suburban areas.
If your subfloor only has minimal damage in one area of the floor, rather than throughout the entire room, you can repair it rather than replace it. This requires only taking up that portion of the floor and laying new subfloor underneath. If the finished floor isn’t damaged you can reuse it. If it was also damaged you can replace finished flooring in that section only.
If the damage to your floor is extensive, such as that caused by flooding in a basement or bathroom, then the entire floor will need to be replaced.
Vapor retarders or barriers installed over the subfloor reduce moisture and help keep the subfloor safe from leaks and flooding. A vapor barrier costs about $0.50-$1.00 per square foot and is a good investment when replacing your subfloor.
If your subfloor replacement project also involves installing a new finished surface on top, such as carpet, tile, or linoleum the price will increase. Finish floor costs start at less than $1 per square foot for laminate to upwards of $16 for expensive tile. Carpet costs between $7 and $12 per square foot.
There will be signs of damage including creaking floor boards, warping, musty smells, and separation.
Between $100 and $300 per joist.
First you’ll need to find the source of the damage, repair the area that was damaged by the water, and install a vapor barrier to prevent new damage.
This will require moving the toilet, sink, and/or bathtub, likely new tiles, thick ¾” plywood, and labor. For a 50 square foot bathroom with junk removal, the average cost at $75 an hour is $900.
Installing a subfloor can take anywhere from 8-15 hours or one to two days.
If your home has old wood planks, a new subfloor can be installed on top of the old planks, saving money on disposal. You can also place plywood or OSB subfloor over a concrete slab subfloor.
Plywood, OSB, or concrete can be used for subfloors. New subflooring materials include DRIcore system, Barricade, Delta-FL, Warmboard, and Tyroc which are all viable options
Cost to replace subfloor varies greatly by region (and even by zip code). To get free estimates from local contractors, please indicate yours.