Author Archive | Johnny Caststone

How To Stop Efflorescence

The acid in rain will eventually dissipate a case of mild to medium efflorescence over time. Depending on climatic conditions, this can take anywhere from a couple months to a year. In cases of heavy efflorescence, or if the client cannot wait, the following remedy will work for an extra fee:

• Wait for 2 weeks of dry weather to ensure the stone is dried out. This could be longer in the Winter.

• Apply 2 coats of siloxane sealer.

• Wait another dry week.

• Wash down with Vanatrol, or any light acid masonry cleaner, per the manufacturer’s recommendations.

• Do not powerwash!!!

Fireplace Installation

Installation Standards

(Applicable for Fireplace and most customized entry installations)
Part I: Hearth Installation

The installation of the hearth is the first step in bringing together your fireplace assembly. (Please note: if your fireplace does not include a hearth continue on to Part II)  Each of the hearth pieces must be firmly secured to the sub floor.  The hearth sections can be set by applying a layer of thinset mortar (commonly used for standard tile adhesion) to the concrete subfloor and to the bottom of each hearth piece.  Carefully position the pieces in the same manner that tile would be set.  The space between each hearth piece must be ¼” to ensure the proper size of the grout joint.  If desired use ¼” shims to ensure this joint spacing.  To ensure that the hearth items are level and plumb, a layer of brick mortar may be required to correct any imperfections of the floor.  If the subfloor is anything other than concrete, we recommend that a layer of tile backerboard be attached to the subfloor. (without mortar)  Once the backer has been installed the hearth can be installed in the same manor as mentioned in the previous paragraph.
Raised Hearth Applications:
North American Stone normally provides special blocks that act as supports for the raised hearth above. These are installed to the subfloor in the same manor as standard hearth pieces. If so desired the void created by these special blocks can be filled with mortar or other masonry waste (i.e. bricks, or CMU block). After the void has been filled and leveled the hearth pieces can simply be installed on top in the same manor as regular hearth installation. (Note: to ensure that the joint space between the special blocks and heart above maintains ¼” use shims if necessary)

Part II: Mantel Leg Installation

After the hearth has been properly secured, the legs can be installed. ¼” shims must be placed under the footprint of each leg.
Apply thinset mortar to the back of each leg piece and set them into proper position, as shown in your layout drawing (provided). Shim the legs as necessary to insure that they are plumb and level.
The legs must then be secured to the 2×4 studs imbedded in the wall. There are two methods to achieve this requirement.
Option 1: The leg piece can be tied to the stud behind the wall by using a masonry tie or L-bracket. Attach the tie or bracket to the wall using a regular wood screw of appropriate thickness. Making sure that the leg is level and plumb, attach the bracket or tie to the stone using Tapcon masonry screws.
Option 2: you can attach the legs by using the “toe in” method. Simply attach the stone to the wall by using Tapcon masonry screws. The screws are drilled into the stone at a 45-degree angle, and then into the wall. This method will require longer screws, make sure that the screws used are long enough to grab the 2×4 embedded in the wall. Take care in keeping the screw hole at least two inches from any edge. Any closer and the stone will run the risk of breaking.
If the legs of your fireplace consist of more than one piece, simply follow the same instructions for the installation of each piece.

Part III: Installation of Mantel Header

After the legs have been properly secured, the legs can be installed. ¼” shims must be placed on top of each leg.
Apply thinset mortar to the wall and back of the header. Carefully lift and set the mantel header on the spacers. Due to the weight of some headers, mechanical lifting equipment may be needed.


Do not use crowbars or similar tools to position the header. This method will chip and possibly break the stone.
Shim as necessary to insure that the header is plumb and level. Next, locate the studs behind the header and mechanically tie it to the wall.
Alternate Header Installation:
Some Fireplace Headers are a complete shelf/header combination. If this is the case the standard masonry tie or “toe in” methods cannot be used. For these instances, a special installation method must be used.
Locate two or more studs behind where the header will be placed. Drill lag bolts into the studs, leaving approximately 1½” of the lag bolt exposed.
Place ¼” shims on top of each leg (as mentioned before). Locate the corresponding position on the back of the header and drill oversized holes or cut slots with a saw and masonry blade to receive 1½” of exposed lag bolt the lag screws. Fill the holes with thinset mortar or epoxy, apply thinset mortar to the wall and back of the header, and carefully set the header on the ¼” spacers that were placed on top of the legs.
Due to the weight of some headers, mechanical lifting equipment may be needed. (See cautions listed above.)

Part IV: Installation of Mantel Shelf

Some Fireplaces have mantle shelves that go on top of the header itself. After the header has been properly secured, the mantelshelf can be installed. ¼” shims must be placed on top of the header. Use thinset mortar to attach the shelf to the top of the header and the wall. For most styles, it is not necessary to mechanically tie the shelf to the wall. (Note: Ensure that the joint spacing is maintained at ¼”)

Part V: Installation of Filler Panels

Some fireplace assemblies require filler panels to finish out the area between the legs, header, hearth, and the firebox itself. Filler panels are installed in the same fashion as regular ceramic tile using only thinset mortar. Use ¼” shims to ensure proper spacing at all joints. With Filler panels take care that their installation will not prevent the proper use of the firebox, do not cover any vents, louvers, or any moving or mechanical items.
Thinset does not hold well when applied to metal. If the filler panels are to be applied to metal only, use a construction adhesive (such as “Liquid Nails”) instead of thinset mortar.
Be careful not to attach any stone to metal that will heat up when a fire is started. Thermal expansion of the metal may break the joint and possibly the stone. Nor should the stone ever be directly in contact with the flame itself.

Part VI: Grouting

Grout and point all the joints. (Caulk is often used in the joints between the mantel and the wall to prevent cracking caused by wall movement.) It is best to soak the stone with water prior to installing grout; this will help prevent the stone from absorbing any mortar and staining. Use a sponge and water to clean all exposed surfaces during the grouting process to ensure that mortar does not dry on the mantel face.
The sand and white cement that has been provided should be mixed with water until it is the consistency of potting soil. The Sand / Cement grout mixture provided will match the color of stone ordered for each particular fireplace.

Part VII: Sealing

After the installation, and if so desired, the stone can be sealed. Ask our customer service or your sales representative for further information.
If you have any other questions you can contact customer service during normal business hours at (972) 562-9992.

Cast Stone Patching Procedure


• Damage that can be seen easily from 20 feet away should be patched. Any corner chips that are ¼” or less in width do not require patching, normally.
• Air & stone temperatures should be greater than 40°F during & 24 hours after patching. Patch during the morning hours on hot days. Avoid patching when the temperature is above 90°F.


• Patching material – The best method is to grind up some leftover stone material from the same jobsite, especially for small chips or cracks. We can supply you with matching sand if this is not feasible.
• White acrylic liquid bonding agent. Available from any local building materials store.
• Mixing containers.
• Water
• 2 spray bottles
• Wood, stainless steel or plastic wedges, or trowels
• Sponge
• Damp rag
• Blue tape & plastic


1. Test patch a piece of leftover stone material & get approval before continuing on the rest of the job.
2. Mix a small amount of patching material (3 parts sand to 1 part mix) with only enough water to make a zero slump mix, or about the same moisture as potting soil.
3. Add a small amount (approx. 1 tablespoon) of the bonding agent. Do not use as a substitute for water. This mix should be as dry as possible. It should have just enough water so it can be compacted in your hand like a dirt clod. Mix thoroughly for 4 or 5 minutes.
4. At this time, the color of the patch mix should be close to the color of the stone when wet.
5. Drench the patch area & surrounding stone surfaces with water from a spray bottle.
6. Spray some bonding agent on the patch area & let stand for 5 minutes.
7. Press the patching mix into the damaged area with a wooden, plastic or stainless steel tool or trowel. For large holes, compress the patch mix onto the wooden tool prior to applying. When the patch mix is over 20 minutes old, replace with fresh mix.
8. Smooth the patch with a wooden tool. Use the least amount of strokes as possible. Too much tooling will create a slick surface. Leave a little extra material on the patch.
9. After initial set, burnish the patch with a sponge, sandpaper, piece of carpet or anything that will create a sugarcube finish. Some trial and error may be required.
10. Cover the patch with a damp cloth or piece of plastic for 24 hours.
11. Wait 5 days & wash down with a masonry stone cleaner.
12. A good patch will not match in color right away & will usually appear lighter. Over the next 3 to 12 months, depending on the climate, curing, weathering & ultraviolet bleaching will blend the color of the patch into the surrounding area.

Architectural Cast Stone

The ideal accessory for your Stone Veneer…

  1. Window Sills
  2. Window Surrounds
  3. Entry Systems
  4. Columns & Capitals
  5. Fireplace Mantels
  6. Balustrade Systems
  7. Watertables
  8. String Course & Banding
  9. Corbels
  10. Finials
  11. Planters
  12. Custom Signage

For detailed information about our entire line on Architectural Cast Stone features and Fireplace Mantels, and to request a catalog, please contact us!