Carefully unpack the hearth, header, legs and riser (if applicable) from the box and inspect for damage that may have occurred during shipment. If you find damage to any of the fireplace mantel kits, immediately report the damage to the truck driver and note on your bill of lading and notify Mantels Direct. Set each piece on the floor.
Step 1 – Start with your hearth
When installing your hearth, we recommend the use of Micore board (may be purchased from us) or a similar product to create a buffer between the hearth and floor. This helps in preventing your hearth from breaking once installed, as well as providing additional flame retardance. Carefully place the hearth on the Micore with the face of the marble facing the firebox, polished edge up.(see fig. 1.1) Center it on the Micore so that you will not have to move it any more than possible. Apply the adhesive around the perimeter of the hearth; leaving two places for handholds, then a couple of "squiggly" lines down the center of the hearth. Be very careful not to have any voids around the perimeter that would cause a corner to break if someone stepped on it. Gently but quickly lower the hearth; this is the most critical time of the installation, as the weight of the marble can cause it to crack if held flat for any length of time.
It is not necessary to apply large amounts of adhesive to the hearth, since it is extremely heavy and the weight helps keep the piece in place. If it were to break, it is easier to remove the hearth if only minimal adhesive is used. When installing a hearth over uneven floors, make sure you cover the entire perimeter of the hearth with adhesive; do not round the corners. Use a thin set bed underneath the hearth if the floor is really uneven, so that the substructure is perfectly level before the hearth is installed. If you are using an adhesive that contains a water base, we recommend that you place the glue on the sheet rock, since it will absorb the water. Note: Do not use a water-based adhesive for Verde Oriental Dark or Venatino marble as bleeding or warping may occur. Green marbles will actually produce a white fungus on the surface, in addition to usually warping, when installed with a water-based adhesive. Also avoid petroleum adhesives, which can stain or etch your marble. Liquid Nails is not a recommended adhesive, as it has been known to bleed through your marble. If bleeding occurs, allow time for the adhesive to cure. Most of the time it will cure out. We recommend Leech F-26 Construction Adhesive, which has been tested as safe for all stones, that we sell (may be purchased from us) – You will need 3 10.3 fl. Oz. cartridges for size 1 kits and 2 cartridges for sizes 2-6. Proper curing of 10 days must be allowed with F-26 to prevent potential flammability of the adhesive. Once it is installed, please cover the hearth with some type of protective covering such as carpet or plastic to prevent any scratches, chips or paint splatters if there is other construction in progress.
Step 2 - Prepare and install your facing legs
Measure for the legs, and check both sides of the firebox; it may be necessary to cut the legs two different lengths (Mantels Direct is happy to cut your fireplace surround facing kit for a nominal fee, if one of our standard sizes does not meet your needs) Cut the legs as required. We recommend a PY 007 dry cut marble blade as this will give you the best cut, short of using a wet saw. If you try cutting more than 20" with a dry blade it will overheat and give you a bad cut. Always make your cuts on a level surface; never let the piece you are cutting fall free. Tape the marble with several strips of good masking tape to protect the marble from scratches. Always begin your cut at the polished edge, if there is a chip caused by the blade it will be on the unfinished edge, which is normally hidden by the mantle leg. Cut with the polished side of the marble up.
Apply adhesive on the back of each leg and place into position.
Step 3 – Install your facing header and optional riser
One must use their own judgment at this point, sometimes it may look better on the firebox for the header to follow the box, even if it's not level. Apply adhesive on the back of the header and place into position. Note: It is usually okay if your header extends beyond the outside of each leg – our fireplace mantels are designed to overlap facing material and can accomodate up to 5" on eachside in most cases.
Note: Radiant front metal fireplaces have solid panels horizontally across the top and bottom. Unless the fireplace instructions state otherwise, fixed-position solid panels can be covered by a non-combustible facing. Circulating metal fireplaces have louvered panels with air vents across the top and bottom. These panels cannot be covered by a facing. Do not cover panels that serve as access doors to gas, blower or other controls.