You can fasten your plywood underlayment using one of the following: galvanized, coated chisel-point staples with a 1/4" maximum crown; galvanized, coated ring shank underlayment nails with a 3/16" diameter head; or flathead wood screws treated with a moisture-resistant coating (such as galvanized or zinc).
It needs to be stapled or it will shift under carpet. Staples allow it a little give without shifting too much. Glue it and the underlay will wear out far faster than the carpet.
Fasten the underlayment with either staples or nails. Start on one corner of the panel and fasten the 8' edge first, spacing 2” along the entire edge. Make sure the fastener is around 1/2” from panel edge. Go back to the starting corner and repeat the process along the 4' edge.
Secure rows by taping them together, this will keep your underlayment in place.
screws are better for the subfloor but will take much longer, nailing is fine along with the adhesive.
Underlayment screws are specifically designed for fastening wood underlayment to wood subflooring. These screws have an intricate thread pattern that tightly holds the two flooring layers together to prevent squeaking, which is one of their advantages over nails and staples.
Many roofers will tell you that staples are fine for installing the synthetic underlayment. Others will tell you that cap nails are more effective. Both options often depend on the slope of the roof itself. Cap nails are typically made of steel and feature a plastic cap to prevent roof leaks, hence their name.
Start in a corner and roll out your underlayment. Trim the roll so that two inches of the underlayment run up the wall. Move onto the next row and continue across the subfloor until the room is covered. You can use duct tape or seam tape to secure the edges and the sections where the underlayment connects.
Stick your underlay to your subfloor – use adhesive glue or staples to make sure that your underlay is firmly attached to your subfloor. Lay your carpet on top – Now you can have your carpet fitted on top. Remember that caring for your carpet is the most important way to look after your flooring and your underlay.
Very often, particularly in a below-grade installation on a concrete basement floor, a vapor barrier is recommended in addition to the underlayment. That vapor barrier would go between the subfloor and the underlayment.
Yes, you must put a staple or screw in every “X”. The minimum spacing requirement is every 4” on center in the body of the panel and every 2” along the panel perimeter to properly secure SurePly® panels to the subfloor.
To ensure that the underlay is secure and stays in place, you should staple down the underlay or use an adhesive to glue it down into place.
Grip-Rite 114ATUL1 1-1/4 in. x 12-1/2-Gauge Bright Steel Broad Head Ring Shank Underlayment Nails are designed for indoor use where corrosion isn't a concern. Thin, broad head ensures a smooth finished surface and strong grip when attaching plywood or subfloor materials.
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.
Floating Underlayment
Most flooring underlayment is installed floating on top of your subfloor. Installers usually lay the underlayment on the floor and start installing the laminate flooring on top. There is no fastening the underlayment to the subfloor.
Each piece of underlay should be laid side by side, with the edges butting up against each other but without overlapping, as this can create an uneven surface for the laminate. Remember to tape the seams together with underlay tape to keep the pieces securely in place and prevent any moisture from seeping through.
It's important to ensure the underlay is rubber or foam-side down. Try to keep the underlay as straight (and bump-free!) as possible and secure in place – either by stapling inside the gripper or by using an effective adhesive. Each roll of underlay should be laid in the same way.
Use a good spray adhesive to stick the edges down and then go over with a staple gun to secure. If you're dealing with a concrete subfloor, use your adhesive instead. Once laid, tape up any joints using duct tape or similar to prevent the paper from moving or sliding out of place.
If you are looking for a subfloor adhesive with a powerful, permanent bond, try Loctite PL 400 VOC Subfloor & Deck Adhesive. It sets quickly and is ideal for heavy-duty interior or exterior subfloor installation in all types of environmental conditions. That means it even bonds wet and frozen lumber!
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)
Staples Size 8mm pack of 5,000 to fit most Tacwise rapid staplers, commonly used to secure underlay to wood substrates.
To nail down the plywood, use underlayment nails, which have a smaller head and rings on the nail shank that prevent them from working loose. Drive nails throughout the entire sheet of plywood, every 6 to 8 inches (see illustration on next page), to ensure the floor is down solidly.