Marble Mantel Installation Instructions
Use these instructions as a guideline only. Check local codes for fire safety. A general knowledge of construction and stone experience is assumed. Have a minimum of one assistant during installation.
– Wet Saw or Diamond Blade (Hand grinder also an option for smaller pieces)
– Tape Measure
– Liquid Nails heavy duty construction adhesive or thinset mortar
– Shims (may be useful)
Step 1: Uncrating and unpacking
Please use caution when uncrating and unpacking the mantel. Be sure that when one piece is being removed, someone is holding the individual components in the crate so there is no shifting of the pieces inside the crate. Safety should be a top priority when handling large and heavy sections.
Step 2: Planning installation and measuring
To begin, lay out all of the mantel components (Make sure not to step on any of the pieces while they are laying on the ground). Arrange the components in the position appropriate for installation. You will need to plan your installation based on the layout of the mantel legs. Make sure you collect all portions of the legs including outside return, inside return (closest to firebox), and leg front.
Mark the center of the firebox on the wall with a pencil.
Step 3: Lay down Hearth
The first step is laying down the hearth on the subfloor or finished flooring. **Make sure the subfloor is completely level before laying down the hearth. Measure and mark the center of the hearth and mark the location on the top surface so it can be easily aligned with the center line on the back wall. Dry fit all pieces before applying any adhesive to the hearth. Apply thinset mortar to the subfloor and bottom and back edge of the hearth. Carefully place the hearth into position and push it back against the installing wall. You will need to make sure the center of the hearth lines up with the center of the firebox. Make sure the hearth is level before continuing on with the installation. Allow hearth to set before placing pieces on top of it. If floor is level, heavy-duty construction adhesive may be used.
Step 4: Assemble legs and returns
Before continuing with the installation, we recommend dry-fitting the mantel into position (with at least one assistant) by carefully positing the leg portion of the fireplace before installing with glue. Align all portions of the legs (outside return panel, front leg, and inside return) and mark reference lines on the wall and hearth/floor with a pencil. Additional framing may be necessary to hold up the legs or face of the fireplace.
Inner Panels/Return panels: You will need to plan return panel/surround panel installation if needed during this first phase. For some fireplace models, these panels can be installed first or last. It all depends on the model profile around the firebox and whether or not the shape of the fireplace allows the panels to be installed later in the process.
If your fireplace legs to not adhere directly to the back wall and there is space behind the face of the leg, it is recommended that a base of thinset be placed inside to act as a footer. The idea is that the thinset will adhere to the hearth, inner and outer leg and wall. Allow to set before placing mantel shelf on top. Some shelves are very heavy and in large block pieces. Make sure legs are sturdy before placing the heavy shelf on top.
Step 5. Install mantel face
The mantel face/freize will rest on the legs or inner panels of the fireplace. Apply a small amount of construction adhesive to the ends of the header/frieze that will join with the legs and position the header into place. Immediately wipe any excess adhesive that is exposed before it dries. Make sure that previously installed portions of the fireplace are held while new portions are being installed.
**Do not step on the hearth during the first 24 hours after installation to allow it to cure evenly.
Step 6: Install Mantel Shelf
Apply glue to all contact surfaces and the back of the shelf and wall. Push against the wall to ensure proper adhesion for all shelf pieces.
Some fireplace shelves come in two or more pieces (ie tiered shelves, decorative frieze) and will need to be assembled in portions. Mantel shelf installation may require additional support with “L” brackets secure to wall frame. This is for cases involving multiple tiered shelves depending on the overall mass and weight. Many of our fireplaces are self supporting
**Make sure there are several hands handling heavy items such as the marble shelf. We recommend one person holding each leg and mantel face while two people lift the shelf into place.
Once installation of the fireplace has been complete, allow the glue to dry for at least 24 hours. Temporary bracing may need to be set up (ie propped by a 2×4) to ensure mantel does not shift while drying.
-Do not use harsh abrasive chemical cleaners such as Comet or Ajax to clean marble fireplace surfaces.
-Wipe off excess glue while you are working
-Wipe up all spills immediately. To clean marble fireplace, use warm water with a soft cloth and mild soap
-Do not use petroleum based polishes or waxes on marble