Installing Natural Thin Veneer Stone
What’s the difference between traditional ‘full thickness’ stone and thin stone veneer?
Traditionally, stone veneer installed on the outside of a structure is 3-5” thick with an average weight of 45-50 lbs/sqft. The first (lowest) course rests on the brick ledge, with subsequent courses each resting on the one below. Masonry ties are used to secure the stone veneer to the wall. This method has a long and distinguished history as a strong, time-tested method of installation. However, in the past, there have been some limitations regarding the ability to use natural stone such as narrow or no ledge, possible weight restrictions, or height restrictions to name a few.
Natural thin stone veneer is created using the same high quality, full thickness stone and processed through special diamond-bladed saws to cut off the outside layer. This produces veneers with nominal thicknesses of 1 1/4 to 1 ½ inches at an average weight of 10 to 15 lbs/sqft (depending on stone selection). Recent breakthroughs in stone manufacturing technology also enable us to create 90-degree corner pieces. Using these pieces gives you the benefit of using real natural thin stone, while the appearance of full thickness veneer.
Why use natural thin stone veneer instead of traditional full thickness veneer?
A narrow ledge or no ledge, or construction or code restrictions relating to weight or height could be reasons to consider thin veneer. Interior applications using thin stone give back more usable space by reducing the thickness of the walls. Thin stone can also be installed over many existing rigid building materials to transform brick, wood, concrete, or other surfaces into beautiful stone finishes. Thin veneer is an outstanding choice when trying to achieve a ‘dry stack’ look. In addition to its aesthetic properties, natural thin stone veneer can also be cost effective for many applications because of typically lower transportation costs (per sq/ft installed) and in many applications, a quicker installation.
Building Stone Institute recommended installation procedures
Type N or S mortar is used for installing Natural Thin Stone Veneer depending upon the type of stone being installed. Check with a producer for a recommendation.
The use of a bonding admixture with the mortar may be recommended to add bonding strength (check with your stone dealer for the recommendation). Please refer to the selected bonding agent instructions for recommended mixture quantities. Extra care should be taken when using bonding agents since dropping can be difficult to remove once they cure. The use of an epoxy, thin set and/or construction adhesives should only be used in interior applications. Admixtures are necessary for all soffit or overhead conditions.
Setting Natural Thin Stone Veneer
Now that the metal lath and the scratch coat have been applied, installation of the natural thin stone can proceed.
- If corner pieces are required for the application it will be best to start with the corners first. This will provide a better guide for your pattern to continue around the corner.
- Most corner pieces will have a long end and a short end. These pieces should alternate in opposite directions, as they are stacked, one upon the other.
- The back of each stone should be covered 100% with a thickness of at least ½” of mortar. A bit more mortar can be added towards the center of the back of each stone.
- The stone should be pressed firmly against the scratch coat wall to ensure a sound bond.
- Extra mortar will ooze out around the edges as each stone is set in place. This extra mortar will fill in around the stone creating your grout joints.
- If you choose not to use this method to fill the joints, then the joints can be filled with grout using a grout bag and/or a tuck pointing tool.
- Make sure to create control and movement joints in the veneer in the same places that they exist in the structure. These control and movement joints serve to allow for the movement of the structure as it settles and moves from environmental changes. Consult a local contractor, your builder, or structural engineering professional to determine the need for these special joints.