Professional Guidance on How to Install Stone Veneer

 Start by making sure you have the right area, and you have a layout of the stone. Stone Veneer can be applied almost on any masonry surface and even over wood surfaces. There are multiple types of stone veneer so the preparation will vary depending on the application.

Manufactured veneer stone could be found in various sizes and patterns depending on where you will be installing it and has great advantages over natural stone because it is lighter and built to fit. 

Vapor Barrier and Install Metal Lath

Vapor barrier
Vapor barrier. Photo mtacc-esa

If the stone veneer is installed on both interior and exterior surfaces, apply a water vapor barrier before installing it. Install the metal lath to create a barrier. The metal lath is installed using 1" roofing nails approximately every 6" and make sure that the studs are penetrated at least one inch. If metal lath is going to be placed over an existing wood surface, place nails six inches apart in every direction.

How to Apply the Scratch Coat

Scratch coat
Scratch coat. Photo elzey flickr

Prepare a scratch coat and cover the entire lath surface with the mixture. The mixture should be about ½ inch thick and when possible use S type Cement or N mortar with a bonding agent. Depending on the layout, you might want to add some tint to the coat; because it can be visible once the stone veneer installation is completed. Scrape horizontal grooves into the coat, using a metal scraper. The scratch coat should be allowed to dry, at least 24 hours,  before applying the stone veneer.

Prepare Mortar Mix

Stucco Mix
Stucco Mixing. Photo StillWorksImagery

Prepare the stone veneer mortar mix. The mix should be a mix of 2 parts (some other would say that 2.25 parts are needed) sand and 1 part cement. Mix thoroughly until a paste consistency is obtained. Make sure there is enough water in the mix to achieve a workable consistency.

Prep the Area and the Stones

Stone Veneer layout
Stone Veneer layout. Photo

Start by washing all the stone, then layout the pieces. Trim the edges using a trowel edge and cut or shape the stones using a circular saw equipped with a masonry blade, a wet saw, maul, and chisel, or using wide mouth nippers.  Remember that trimmed edges will be covered later by using grout. It is important to maintain the stones damp to minimize the possibility or absorbing moisture from the mortar.

Apply Mortar Mix

Mortar mix on stone veneer
Mortar mix on stone veneer. Photo

Apply a ½ inch thick mortar layer onto the wall and to the back of the stone. The mix should be mixed with enough water so it will not dry and at the same time, will allow you to level the surface where the stone will be installed.

Install the Stone Veneer

Stone Veneer
Photo by Armchair Builder

The stone veneer shall be installed first around corners, pressing the stone firmly into the mortar. To install the stone, hold it against the wall surface for about 10 seconds, rotating slowly, allowing some of the mortar to squeeze out. If the stone slides or slips, then the mortar layer might be too thin. Continue with the flat stone installing them into the corners. Stone trimmed edges shall be carefully places in areas where they will not receive that much focal attention. Always start at the bottom and work your way up.

Finishing Joints on Stone Veneer

Veneer joints using bag
Veneer joints using bag. photo Youtube

For better results, keep the joints narrow and consistent. Stone veneer joints shall be filled with a grout mixed, using a grout bag. Make sure all trimmed edges and pieces are covered with mortar. Joint depth shall be uniform and narrow joints will provide a nicer appearance. When the mortar mix starts to dry, use a pointing tool to push the mortar into the joints.

Clean and Seal

Stone veneer sealed
Stone veneer sealed. Photo glomarble

Remove any excess dirt or mortar excess using a mix of vinegar and clear water. It is important to clean stone veneer within 30 minutes. Otherwise, the mortar will be impossible to remove. Use a steel brush and rub the cement off the stone surface.

Seal the veneer stone following manufacturer’s instructions. Re-seal them every other year or when required to maintain aesthetics. Sealed stone may be easier to clean than unsealed stone, and certain sealers also repel stains.