Underlayment Nails

How far apart should underlayment nails be placed?

These nails should be driven over the entire surface plywood sheet, at intervals of 6 to 8 inches.

What should the ideal thickness of underlayment be?

Ideally, the underlayment should be approximately 1/4 to 1/2 inches thick, to provide a flat & smooth surface for the floor.

What strategies ensure the smooth installation of underlayment?

• In order to prevent workers from scratching and denting the smooth surface, install the underlayment as late in the construction process as possible.
• The underlayment may have two sides, so It should be installed with the better side up. If it is made of A/C plywood, the 'A' side should be facing upwards.
• Place the underlayment parallel to the floor joists. Never align the seams of the underlayment with those of the subfloor. Instead, space them apart by at least 2 inches. This improves the floor's stability and lessens the spread of lines through resilient floors.
• Keep a gap of 1/32 inches at the underlayment edges to accommodate natural swelling.
• Avoid sitting on hand tools or stepping on loose nails.