How to Install Stone Veneer

Now that you know which stone veneer product you want to use, you may be asking yourself: "How do I install stone veneer?" Don't worry! We've got you covered. Below is our step by step guide to help you learn how to install stone veneer.

Stone Wall Installation Guide

Step 1: Surface Preparation

Wood or Metal Frame Construction

- Interior Applications -

Apply rigid backer board (1/2” plywood, drywall or cement board) to frame construction. Then apply weather resistant building paper or equivalent over rigid sheathing. Install from the bottom up ensuring upper layer laps lower at least four inches. Attach 2.5 lb. expanded, galvanized, metal lath to each stud 6” on center-vertically, penetrating the studs at least one inch. Be sure to attach the lath hoizontally. The surface should feel rough as you rub your hand upward. Lap lath 4” at all seams and wrap all inside and outside corners 16”, or attach to stud. Make sure vapor barrier is installed smooth. Lath needs to be tight; any bubbles should be nailed or stapled down to prevent “bounce”. When corners are wrapped it is important to nail into the corner stud from both sides.  

- Exterior Applications -

Exterior plywood is recommended as the rigid backer board. OSB is not recommended as the exterior sheathing. Apply building paper and lath as for the interior application. Check with local building officials on the type, weight and number of layers of weather barrier (building paper or equal) that is required in your area.

Concrete Block, Poured Concrete or Brick Stone

Stone Veneer can be installed directly to clean, unpainted or unsealed brick, concrete block or poured concrete surfaces (interior or exterior) without applying metal lath. On previously coated surfaces, sandblast or waterblast to thoroughly clean. Where thorough cleaning is not possible, install metal lath and apply a scratch coat application.

Step 2: Scratch Coat Application

All lathed surfaces should be covered with a 1/2” to 3/4” coat of mortar and allowed to set approximately 30 minutes prior to installing stones. Then brush with a soft bristled brush (to roughen up surface to ensure a stronger mechanical and chemical bond.) Mortar mix consists of one part type “N” cement and two parts mason sand. (Example: One pail cement to two pails sand.) Mix with enough water to achieve a workable consistency. The same mortar mixture is used for scratch coating, setting the stone and grouting the joints. Dry pre-mixed mortars, especially designed for masonry, may also be used. Ask your Menards representative for specific product recommendations and mixing instructions.

Step 3: Stone Layout and Arrangement

Before stone installation, lay out a quantity near the work area. Blend multiple boxes to ensure a proper mix of size, shape, texture and color of stones allowing you to arrange the stones in the most pleasing design. Then apply stones, mixing colors randomly.

Step 4: Application

“Butter” the stone by applying an even, 1/2 inch thick layer of mortar to the back of the stone. Be sure to cover the entire back of the stone with mortar. Press the stone firmly into place so that the mortar behind the stone squeezes out on all sides. Use a wiggle action while applying the stone to insure a good bond. When applying to clean, concrete and masonry surfaces, dampened the wall prior to installation. This will aid adhesion to the existing surface. Adhesion can also be improved by adding a liquid bonding agent to the mortar mix.

Tip: Install the corner stones first starting at the bottom and working up. Install the balance of the wall from the top down. This aids in keeping the stone face clean of mortar.

Remove mortar from stone face, as necessary, during installation. Allow mortar to become “crumbly”, then remove with a trowel or brush. Do not allow mortar on stone surface to dry overnight.

When necessary, stones can be cut and shaped with a masonry hammer, masonry saw or nippers. Position cut edges away from view when possible. Trimmed edges are easily concealed at grouting.

Step 5: Grouting the Joints

After the stone has been applied to the surface, fill a grout bag with mortar and as in decorating a cake, fill the joints with mortar. Grout bags are available from your supplier. While grouting, be sure to cover any noticeable broken or cut edges with mortar.

Step 6: Striking the Joints

When the mortar joints become firm, use a wood or metal strike tool to push the mortar into any cavities or voids creating a seal around each stone. Any holes, gaps, or voids must be filled in with mortar to prevent water or pests from occupying the space. Use a tuck pointer or similar object to clean the edges of each stone to prevent cracking of the grout. Use pressure to force the mortar into the joints. This will thoroughly seal the joint edges. Be careful not to work the joints too soon. This will cause the mortar joints to smear.

Step 7: Brushing

Brush the mortar joints with a small whisk broom to smooth and clean away any loose mortar.

Do not wash off with clear water. This will result in a milky residue. Brush off any mortar spots from the face of the stone veneer. If desired, use a mild vinegar and water solution to remove any remaining mortar spots. Loose mortar and mortar spots should not be allowed to dry overnight.

Step 8: Completion

When desired, a high quality “breathable” masonry sealer can be applied on any stone veneer, especially on those exposed to severe freezing and thawing, excessive moisture, or conditions which could discolor or stain the veneer. This must be a breathable, masonry sealer. Any other type of sealer voids the warranty. Follow recommended application instructions for your selected sealer. Test several unused pieces before general application. Some sealers may alter the appearance of the masonry.

Step 9: Cleaning

During the stone application remove all mortar on the face of the stone by allowing the mortar to set-up until crumbly, then remove with a dry bristle brush. Do not allow mortar on stone surfaces to dry completely.

To remove dirt, smoke or other stains, use a mild solution of granular detergent and water. Scrub with a bristle brush and rinse with fresh water. Do not use wire brushes. Do not use acid, salt or other “de-icing” materials. They will cause damage to concrete and masonry materials. CAST NATURAL STONE is not warrantied against deterioration or discoloration caused by acid, salt or other chemical or cleaning agents.