Wrap a sheet of medium-grit sandpaper around a sanding block. Smooth any part of the drywall that is not level or is rough to the touch. Wipe away any sanding dust with a moist towel.
Clean the drywall bonding surface of all dirt, dust and residue using a hand vacuum, hand brush or moist towel. Also check that the bonding surfaces of the FRP panels are completely clean. Any debris on either bonding surface can compromise the strength of the adhesive.
Don your safety goggles and mouth mask. Ensure that your area is well ventilated. FRP adhesive can emit harmful fumes and should never be used in a small, contained area.
Open your container of FRP adhesive and mix if the manufacturer's instructions require it. Dip your trowel into the adhesive and wipe any excess on the inside lip of the can. Apply the adhesive smoothly in a cross-hatch pattern across the entire panel, re-dipping the trowel as needed. Once applied, the coat should be even and uniform across the entire panel.
Fit the panel onto your drywall, pressing either corner on first. As the panel begins to adhere to the drywall, use a laminate roller to help flatten out any air bubbles that may occur. Roll the entire panel once it has been set in place on the drywall.
Perform adhesive application, mounting and rolling for each additional piece of FRP. If you will be arranging the panels right next to each other, leave as small a seam as possible. There should be no noticeable gap between each panel once you finish.
Allow the adhesive to cure for the time recommended by the manufacturer's instructions. Moisten a rag with mineral spirits and wipe up any excess adhesive on the top of the panels.