Fasteners with Stainless Steel (SS) wings are typically installed into 5⁄8″ drywall with tile. Only fasteners with Stainless Steel (SS) wings are acceptable for acrylic/fiberglass surrounds and plaster. For these fasteners, the acceptable wall substrates (which exceed all building codes for grab bars) are: 5⁄8″ Drywall—Painted or Wallpapered 5⁄8” Drywall with Tub Surrounds 1⁄2″ or 5⁄8″ Drywall with Tile, Marble & all Stone substrates 1⁄2″ or 5⁄8″ Drywall with any Panel type, including Fiberglass, Faux Marble, Acrylic, and Plastics Multiple layers of Drywall, Plaster, and Lath 1⁄4″ Acrylic/Fiberglass Tub Surrounds Most Wall Panels, All Masonry type boards—with or without decorative panels For fasteners with Fire-Retardant Plastic (FRP) wings, the acceptable wall substrates are: 5⁄8″ Drywall—Painted or Wallpapered 5⁄8″ Drywall with Tub Surrounds 1⁄2″ or 5⁄8″ Drywall with Tile, Marble and All Stone substrates Multiple layers of Drywall, Plaster, and Lath Most Wall Panels, All Masonry type boards—with or without decorative panels