If you are using the new ply directly as underlayment i would use 1 1 2 screws to attach to decking.
Recommended screws 3 4 plywood flooring.
Typically the 3 inch variety is used to secure plywood subfloors.
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 a little extra added power is needed.
Conventional wisdom has always been that screws with fine threads are best for hardwoods oak cherry maple birch etc.
The number refers to the thickness of the screw.
Once reserved for subfloors and sheathing construction grade plywood is now making a splash as affordable residential finish flooring.
While coarse threaded screws drive and hold better in softwoods plywood and.
Each is available in lengths from 1 1 4 to 3 inches.
Hey there i m getting read to screw and glue some subfloor in.
A wider gap between clusters of nails may indicate a floor 1 5 inches thick which would require subfloor screws that are 2 to 3 inches long.
If it were me and i was going to put additional underlayment down on top of the new 3 4 ply i would use at least 2 1 2 screws and do my best to find the floor joists below.
Some experts suggest that 15 32 inch plywood should be standard if the underlying floor joists are spaced 16 inches apart or less but slightly thicker 3 4 inch plywood should be used for joists spaced further apart.
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.
Floors with nailheads 16 19 inches apart are likely about 3 4 inch thick which suggests the need for screws at least 1 3 4 inches and possibly up to 2 inches long.
Framing flooring and sub flooring screw pattern and size for 3 4 plywood subfloor.
These sheets install directly over floor joists which cross the floor every 12 to 16 inches to provide the support necessary for the flooring surface.
Three fourth inch sheets are the standard in plywood subfloors.
A thicker subfloor takes a 3 inch screw.
Remove the existing flooring.
Use a heavy duty drill to drive phillips head wood screws through the subfloor into the floor joists.
Once the point has pulled a wood screw down into the material it s up to the threads to continue driving it the rest of the way in.
There are two basic ways to go.
The floor joists beneath a plywood subfloor can be a range of heights but 6 inches is a standard.
The 3 4 inch thick subfloor takes a 2 inch screw.