25 Quick Tips for Installing Adhered Masonry Veneers
A long-lasting end result is an achievable goal when you follow a few simple tips.
Installation methods for adhered masonry veneers vary among installers, but the goal is the same: a long-lasting end result. I have seen tricks and techniques that make sense – some that make a real difference in the end result. Here are a few lessons you can implement for success:
- Know how square your work area is. When laying out for corners, the time to make adjustments is when you are installing the lath and before you begin veneer installation.
- If working on an exterior veneer against a sidewalk or a patio that slopes, always level your work. When possible, install from the top of the wall, down, to place the veneer cuts at the floor level.
- When installing lath against framing, mark your stud locations to ensure that the person anchoring the lath can attach the anchors directly into the structural member.
- When installing adhered masonry veneers over sheets of plywood or oriented strand board (OSB), assure a minimum 1/8-inch gap exists between the sheet edges to allow thermal and moisture material dimension changes. If installed with the edges touching, the sheets can buckle and pop the veneer off later.
- Always inspect the WRB and weep screed prior to beginning your work, and repair any loose edges or penetrations before you mix your mortar.
- When applying the base coat on lath that has been in direct sunlight and is hot to the touch, use a spray bottle to cool the metal before applying the mortar.
- Spot measure the depth or thickness of your base coat and assure it is ½ inch thick or slightly greater.
- If you complete your base coat application on windy days, cover your work with plastic to slow evaporation and allow the mortar to dry properly.
- On high-temperature days, mist the base coat during drying to reduce cracking and help the mortar cure to the proper strength.
- Scratch level horizontal and plumb vertical lines in your base coat. Even though the lines will be covered by the top coat, they can serve as a reference for aligning the application of veneer material in areas where the top coat has not yet been applied.
- When mixing the base or top coat of mortar, mix mortar for three minutes, let it sit for about three minutes, and then continuing mixing for an additional three minutes to allow the mortar to become more workable and exhibit a longer board life.
- Admixtures need to be kept from freezing and out of direct sunlight prior to use for best performance.
- Install your corners as early in the installation as possible. If you have to cut the veneer to make bond, install the cut pieces as far from the corners as possible within the veneer to hide the cuts.
- Lay out your veneer from several boxes of material before you begin installation. Blending materials from several boxes will minimize any color variances in the manufactured veneer.
- There are two ways of setting veneer units. You can apply a thin layer of topcoat over the base coat and place a ½-inch back-butter on each individual unit prior to placing. The other option is to back-butter only with a ½-inch-thick spread on individual units.
- Total base coat and top coat must be a minimum of one inch thick from the outer surface of the WRB to the back of the veneer unit.
- Push and slightly rotate each veneer unit back and forth to create a secure bond between the unit and the substrate.
- When possible, install units from the top of your work to the bottom, which will reduce mortar droppings on finished work and make clean up faster and easier.
- Install cut and smaller sized units at the weep screed, where they will be less visible.
- Never mess with wet mortar droppings. Let them dry out before removing them with a horse hair brush.
- Never use masonry cleaners, wire brushes or pressure washers when cleaning adhered masonry walls.
- Always turn your scaffold walk boards up at night to avoid staining from rain shower splatter.
- Grout your joints once initial setting has occurred, using a tuck pointer and hawk or a half-filled grout bag. You will achieve more with less, and it is easier to control in tighter applications.
- In areas where snow from parking lot plowing accumulates against a veneer installation, protect the adhered veneers from contacting the snow. Deicing salts can quickly damage the appearance of the veneer units.
- Adjust water sprinklers so they do not spray the veneers.