Concealed Screw Attachment of Stone Panels

Concealed Screw Attachment of Stone Panels

Learn how to install StonePly using concealed screw attachment of panels. Get a list of materials and tools needed plus instructions in a printable PDF manual.

Download Concealed Screw Attachment PDF


Installers should be craftsmen with construction experience. Installers should read the instructions. Follow all OSHA and other safety requirements. StonePly panels are a finished natural stone product. Use care to protect them during installation.

Installation Supplies and Tools

Installation Supplies

  • Plastic glazier shims: U shaped shims 1/16", 1/8", and 1/4" thick x 2 1/2" long minimum
  • No. 8 Tek Screws, Philips Head
  • Masking Tape
  • Structural Silicone: Dow Corning 795 or equal

Installation Tools

  • Screw Guns
  • Locking C-Clamps (Vise Grips)
  • Drill and bits
  • 48" Level and 24" Level
  • Circular Saw with dry cut diamond tipped blade (Use a smooth rim blade for smooth cuts)
  • Glaziers pry bar to pry stone panels when shimming (a screw driver can be used)
  • Suction cups for handling polished or honed stone panels

Framing Construction

Steel stud or furring should

  • be true and plumb
  • must have a maximum deflection limited to L/240, not to exceed allowable stresses

Lateral support and bridging should be installed. Do not rely on StonePly stone panels to provide lateral support for wall framing.

The steel stud framing should have a maximum variation from a true plan of 1/8 inch in 10 feet. Correct any defects prior to proceeding with stone panel installation. Framing studs must be located with studs at panel joint locations.

Panel Storage and Staging

Stone panels should be stored in a clean, dry area. While StonePly panels are strong and impact resistant, keep in mind that they are a finished product. The natural stone facing can be chipped at the edges and softer stones can be scratched. Limestone, marble, travertine, and other softer stones can be stained by dirt, mud, or construction materials. As they are removed from their crates, StonePly stone panels should be placed on carpet, foam, or other padded surface to protect the stone edges. Also consider laying the uncrated stone panels out in the order they are to be installed to speed up the process and minimize mistakes.


  1. Use the shop drawings, tape, and a laser level to mark the exact positions of panels on the wall.
  2. Check to ensure that each panel edge will have framing support. 
  3. Using a laser, find the most outward point of the framing. This will be the installing "plane", as all other panels will need to be shimmed out to that level.
  4. Using string lines or a rotating laser, set at least two inches from the most outward point of the framing as a reference line to establish the plane for all of the StonePly stone panel faces.
  5. Lay panel facedown and attach the anchor plates to the back of the panel with screws.
  6. Set stone panel in place, lean it forward and apply a walnut sized glob of structural silicone, 24" on center to the framing members at the center of the stone panel.
  7. Hold the stone panel in place, and clamp to the framing with the padded C-clamps. Shim as needed.
  8. Screw the anchor plates to the framing.


  • Start with the bottom row of stone panels and work up.
  • Installation can progress vertically or horizontally depending on how the stone panels are lain out.
  • Use care when aligning stone panel joints, shimming as necessary to maintain the installing plane.
  • Use the C-clamp to hold the StonePly stone panel in place while screwing the anchors to the framing.

Disclaimer and Warning

These are general guidelines, not full instructions. Every job is different, and a competent, experienced professional, skilled in construction, carpentry, safety and proper use of tools should direct the work. Consult with a professional engineer to produce calculation and recommendations for fastener spacing to meet wind loading and anchor spacing.