Installing a plywood subfloor costs between $4.50 and $10 per square foot, including material and labor fees.
Subfloor replacement typically costs about $3 to $10 per square foot. This range can vary based on labor costs, which will add $25 to $30 per hour, and the type of subflooring you choose.
To avoid buckling, subfloor panels should be spaced with a 1/8-inch gap at all edges and ends to provide room for naturally occurring expansion. Tongue-and-groove edges on many premium floor panels, such as Weyerhaeuser's Edge Gold® OSB panels, are designed to self-gap.
The long beams that provide the main structural support for the floor can cost $200 to $500 per room or $10 to $67 per square foot to repair. A full replacement costs $5,000 to $20,000. If you're only repairing individual joists, expect to pay $100 to $300 per joist.
When a subfloor starts to creak and the nearby floors are uneven, sunken, or sagging, it's likely time for a replacement. Repairing a damaged subfloor has a typical price range of $300 to $2,500.
Rather than nails, screws are best to use for subfloors — these fasteners are convenient, easy to remove and capable of providing torque that nails lack. Because of their structure, screws can penetrate plywood more easily and improve the connection, whereas nails can weaken the plywood.
It might sound counter intuitive at first to leave space between your floor and your wall, but you should always leave a ½ inch to ⅝ inch gap between drywall and the floor. There are several reasons for this: Drywall absorbs moisture.
Subflooring can last a very long time. Under normal conditions, a subfloor can last as long as the house itself. However, should a subfloor be damaged or defective, it may only last 20 to 30 years. Should this be the case, a homeowner might need to peel back the layers of flooring and get to work.
A flooring contractor can replace subfloor.
Contractors partially can replace subfloor from underneath if there is access; they'll need to inspect the joists and loosen screws, and then the main job of repairing and replacing subfloor is done from on top.
Floating Plywood Subfloor
As the least-expensive subflooring option, floating plywood's only barrier between the concrete and the plywood is plastic sheeting. The advantage of this type of basement subfloor is that it is thin and easy to install. Air and water cannot flow underneath this type of basement subfloor.
Average material cost of flooring at Lowe's is about $1.95 to $6.75 per square foot, and installation will cost around $2.25 to $8.50 per sq. ft.
The average cost of installing hardwood floors is $3–$10 per square foot for materials and $3–$8 per square foot for labor, totaling $6–$18 per square foot.
What are the costs to fix sagging floors and subfloors? The typical costs for repairing sagging floors start at $1000 and can go up to $10,000, with the average rate being around $300 per square foot. But this can vary depending on the extent of the damage and materials needed to get the job done.
Installing Plywood Underlayment
You can cut sheets with a circular saw, jigsaw, table saw, or handsaw, just like any wood sheet material. While underlayment traditionally was glued down to wood subflooring, most manufacturers today recommend installing it without glue, which greatly simplifies the installation.
Wooden floors on floor joists can be done with a single layer, but for best results, you will want to use tongue and groove 3/4 inch thick “AC” labeled plywood. Ceramic tile fairs better on cement board over plywood, and with a crack relief/prevention membrane.
Underlayment panels should be installed with the long direction, or strength axis, perpendicular to floor joists, never parallel to the subfloor seams. All panel edges should be staggered at least 2 inches to the subfloor seams for increased stability.
Both plywood and OSB are effective choices for your subfloor needs, but OSB may be a better option for a garage than plywood. Plywood is a better option for projects that require a lot of cutting and molding, while OSB is a good option for those who need to cover areas where moisture exposure may be an issue.
Subfloor. Screw spacing should be 6" o.c. at the boundaries and 12" o.c. in the field, assuming an unblocked diaphragm. For blocked diaphragms increase the numbers of screws by 15%.
No subfloor is perfectly level, but any signs of unevenness and high or low spots must be remedied. Please follow these requirements: Subfloor unevenness cannot be greater than 3/16 of an inch over a 10-foot span or 1/8 inch over a 6-foot span. Subfloors must not slope more than ½ inch per 6 feet (25 mm per 1.8 m)
Plywood is considered the most popular material used for subflooring, it has been used since the 1950s and remains one of the top choices for contractors. Standard plywood works perfectly fine as a subflooring material, but the best option is ¾” tongue-and-groove plywood subflooring.
Moisture Issues
Moisture can also cause floors to become uneven. If there is excessive moisture in the ground underneath your home, it can cause the soil to expand and contract, leading to uneven floors. This is particularly common in areas with high humidity or frequent rainfall.