Choosing the Proper Fasteners for Installing Plywood Underlayment
July 20th, 2018
Do not glue plywood underlayment panels to the sub-floor. Gluing plywood underlayment panels to the sub-floor can cause problems such as a tack and release floor that crackles when you walk across it. In addition, gluing the underlayment panels to your structural sub-floor will eliminate the opportunity to remove the underlayment for a future floor replacement. Instead, fasten the plywood underlayment panels with staples or screws. In this blog post, we will discuss the proper specifications to follow when selecting the fasteners.
We recommend a pneumatic fastener tool that incorporates an adjustable depth-drive control to prevent fastener “blow-through” or “over-driving.” If this feature is not available, adjust the air pressure on the compressor to an appropriate level to avoid these issues. We recommend that you shoot a few test fasteners once you think you have the compressor at an appropriate level just to make sure.
Fastener choices include the following:
- galvanized coated chisel point staples with a 1/4″ maximum crown
- galvanized coated flathead screws with a minimum 3/16″ diameter head
Do not use drywall screws. You can use decking screws as they are properly coated to prevent rusting. Do not select a fastener that is uncoated, cement or rosin coated, as they may rust and discolor your finished floor.
The length of the selected fastener should be a minimum of 5/8″. It should not be so long that it penetrates the combined thickness of the plywood underlayment and subfloor. The fasteners should not protrude out of the bottom side of the subfloor.
See our complete plywood underlayment installation video at www.InstallSurePly.com.