Nail Down Application Installation Requirement Installation Requirement: For nail down applications, it is necessary to use a glue-assist method for The Storehouse Plank Collection of solid, prefinished flooring. A PVA type adhesive shall be applied as a “glue-assist” to flooring boards that are being nailed or stapled down. (Option 1) A 1/4″ bead of adhesive may be applied directly to the subfloor 1/2″ away from the tongue of the previously installed row of flooring. (Option 2) Alternatively, adhesive may be applied in a 1/4” bead in a serpentine pattern to the underneath side of the board before nailing or stapling down. If a glue-assist method is used, underlayment should not be applied to the subfloor. Adhesive should be in direct contact with both the flooring and subfloor.