Every 6 to 8 inches along the edges and every 12 inches in the center of the plywood. I always screw mine every 6 inches along the edges and every 6 inches in the center. And you want to ensure that you are hitting the floor joists below it.
Panels should be fastened securely to each joist at 300mm centres. This will generally equate to 25 – 36 fasteners per 1.2 x 2.4m board. The minimum edge distance for nails or fasteners should be at least 8mm and fixings should be installed into every joist.
(3) Fasteners for 5-ply plywood Underlayment panels, and for panels greater than 1/2 inch thick, may be spaced 6 inches on center at edges and 12 inches on center each way intermediate.
The general rule of thumb for standard deck fasteners is 350 screws for every 100 square feet of decking, which is based on standard 6" wide boards (5-1/2" actual), and 16" joist spacing.
"When fastening the upper layer of plywood, OSB, or 2x4s above the rigid foam, use the same number of screws that you would use for furring strips installed on walls—basically, one screw every 24 inches along each rafter, with a minimum penetration into solid wood of 1½ inch.
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%.
Environmental Impact: OSB's manufacturing process utilises smaller, fast-growing trees, which could be considered more sustainable. Ease of Installation: Both materials are relatively easy to install, with plywood being slightly more forgiving due to its ability to hold screws along the edges better.
Because of their structure, screws can penetrate plywood more easily and improve the connection, whereas nails can weaken the plywood. The main categories of screws designed for subfloors include galvanized screws, steel screws and cement board screws.
The standard nailing pattern for sheathing depends on the type of sheathing material and the local building codes. However, a common nailing pattern for wood structural panels (plywood or OSB) is to place nails every 6 inches along panel edges and every 12 inches along intermediate supports (studs, joists, rafters).
While there is no fixed rule, a general guideline is to use at least two screws per joist per deck board. This ensures sufficient attachment and minimizes the risk of sagging or warping over time. For narrower deck boards (less than 6 inches wide), it is recommended to use three screws per joist, evenly spaced.
Screws, if driven properly, prevent creaking floors. A screw firmly holds the subfloor in place, which ensures a squeak-less floor for years to come.
Determining the Ideal Screw Length in Woodworking
For most woodworking projects, the rule of thumb is that your screw should be at least twice the thickness of the thinnest piece being joined. For example, if you're fastening a 1/2‑inch thick board, you would ideally use a 1‑inch long screw.
Improper Spacing Between Panels
Like any wood product, OSB will expand and contract after installation; without a small gap between panel ends, the expansion could cause buckling. Most manufacturers recommend 1/8 inch at panel ends and edges.
Many home walls end up with over 100 holds per sheet of plywood. For now, don't worry too much about the specific hold shapes, just make sure you have the right mix of hold types.
While installing panels too tightly or without any gaps won't allow the material to expand and contract, leaving too much gap can cause excessive movement and noises. To avoid this, you must leave a proper expansion gap of 1/8” to 1/16” between the subfloor panels.
Generally, nails (6d ring or screw shank, or 8d common) should be spaced 6 inches on center along supported panel edges and 12 inches on center on the panels' interior supports, or as specified on the construction drawings. Many manufacturers print a fastener template directly on the panel face.
Because the wood expands and contracts as a reaction to moisture, nails provide a more flexible fastening job.
Pockethole Screws work well in traditional cabinetry using 3/4 in. to 1-1/4in. material and allow the user to create miter joints and piece joints quickly and easily without clamps.
Subfloor and Structural Plywood
For traditional plywood flooring installations, where the plywood is directly attached to the subfloor, the recommended thickness typically ranges from 5/8-inch (15mm) to 3/4-inch (19mm) plywood.
PAMFast AutoFeed Screws are the preferred choice for interior and exterior subfloor. They provide a firm grip between connecting lumber, which makes them perfect for subfloor. They have a head that works with a variety of bits, including Phillips and torque-head screws.
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.
OSB can be manufactured into panels that are larger than plywood. OSB is more uniform, so there are fewer soft spots, such as those that can occur in plywood. OSB is less expensive than plywood. To build a typical 2,400-square foot home, OSB may cost $700 less than plywood.
Use 1-1/4-inch screws for basic tasks where strength is less of an issue or when attaching two 3/4-inch-thick boards across the grain. Keep some 2-1/2-inch deck screws for screwing into end grain, plus some stronger 3-inch screws for attaching into end-grained boards or when you need a little extra power.