Bring Your Home Exterior Design Dreams to Life
With the weather warming up and the days growing longer, it’s the perfect time to spruce up your home exterior! Whether you’re building a backyard retreat (complete with firepit!) or looking to give your home exterior a new look, one product stands out. Cultured Stone veneers are a stylish and versatile option that are great for many projects. What’s more, they’re the right tool for anybody – DIY or contractor, for jobs big and small. The installation process is simple and can be completed in just a few days.
Materials Needed
Before you begin the exterior installation process, make sure you have the following tools and materials on hand:
• Cultured Stone manufactured stone veneers
• Safety equipment (N95 mask, safety glasses, work boots, etc.)
• Flashing
• Rain screen
• Jointing tool
• Masonry brush
• Spacers
• Water resistant barrier (WRB)
• Grout sealer
• Pointing trowel
• Notched trowel
• Welded wire lath complying with ASTM C933
• Corrosion resistant fasteners (staples, roofing nails, etc.)
• Mortar (scratch coat, setting bed, and pointing)
• Drop cloths and cleanup supplies
Job Site Setup
Before beginning your project, start by storing all your materials out of the way, but still convenient to application. Be sure to eliminate any trip hazards and keep your Cultured Stone veneers protected from any worksite dust or inclement weather. Use your drop cloths to protect any landscaping.
Wall Prep
If your home exterior project has metal or wood framing, begin by applying two layers of WRB as independent layers, lapped in “shingle” fashion. Evenly install your flashings across the primary layer. Make sure that your primary WRB meets all building codes and manufacturer requirements, depending on your project.
After installing the primary layer, apply the second “sacrificial” layer of WRB, to allow incidental water to drain down and out. Lap each material 2” horizontally and 6” vertically, fasten with WRB-approved fasteners.
Make sure that any contact with doors or windows are flashed properly. Head flashings and drip screen will help resist water damage.
Adding Your Rain Screen
For any home exterior projects that involve adding Cultured Stone veneers to your walls, adding rain screens adds an extra layer of protection against water damage. This physical airspace behind the cladding provides a larger path for drainage, using a ventilation drying effect. Standard building codes allow for just a single layer of rain screen, but be sure that it is at least 60 minute building paper or equivalent.
Lath Application
Depending on whether you use expanded metal, woven wire, welded wire, or alternative lath, it needs to transfer cladding load to your framing. Make sure your fasteners penetrate the framing and are spaced evenly. Typical applications would have fasteners 16” on center, spaced a maximum of 7” vertically.
When placing lath, always end lap joints over framing and fasten them there. Any that does not land on framing will need to be wire laced. For all overlaps, use at least 0.5” horizontally and 1” vertically and at end laps. NEVER end your laps at a corner, as this creates sharp edges and breaks in the barrier.
Mortar Application
Once the lath is installed, check for roughness. This will tell you the direction of the cups and determine which direction to apply the mortar. Follow the same path as the cups, using consistent pressure with your trowel to ensure mortar completely fills the lath. Whether your mortar is pre-blended or created on-site, make sure it meets NCMA standards.
Aim for at least a 0.5” to 0.75” layer of mortar, as anything less than 0.5” inches is too thin and runs the risk of cracking. Cover all lath at your target thickness, keeping at eye out for thin spots. You may need to apply a second layer to achieve desired thickness and levelness.
After letting the mortar cure for a few hours, it’s time to texture the surface with a scratch coat. Use your notched trowel in even, horizontal strokes across the mortar. This will allow your Cultured Stone to connect easier to the walls or surfaces. Allow at least 24-48 hours for the mortar to cure completely.
In warmer weather, remember to lightly mist your scratch coat and stone units to keep them properly hydrated.
Setting the Stones
Before installing the stones, check the back of each and remove any dust or debris. Then, gently dampen the scratch coat and stone units with clean water. Make sure both look saturated, but not shiny with water.
Apply your setting bed mortar onto a few square feet of the prepared surface with your trowel. Then apply a thin “back butter” of mortar to the entire back of the stone unit. Press the stone into the setting bed mortar on the wall. Leave enough space for joint gaps, and then leave the stone be.
Clean out mortar droppings as you go along and check stone bonding periodically. If a stone needs to be re-mortared, remove all original mortar first before re-applying and re-setting.
Be aware that if you’re setting stones in corner layouts, that flat stones can be nested and alternated to create a uniform look.
Large Format Stones
For large firepits or radical home exterior redesigns, large format stones are a viable option. The key to proper bonding is achieving a full setting bed of quality mortar, with ample spacing between units. You should also take time to ensure your scratch coat is level and straight, adding another coat if necessary. Many of these large format stones are fitted with mortar joints, but you may need to use a larger 3/8” inch joint to make filling with mortar easier. Use spacers on all four sides of each unit to maintain uniform mortar joint gap, and remove carefully after the mortar has cured.
Joint Treatment & Wrap-Up
With your stones placed and spaced appropriately, you’re now ready to fill in your joint gaps. Make sure the mortar you use is smooth enough to flow easily through a grout bag. Carefully remove any excess setting board mortar from the joints before filling.
Fill in each joint gap evenly with mortar, being careful not to disturb the stones as you go along. Once filled in, wait until the mortar is thumbprint hard, then you can tool the joints as needed. Depending on your desired look, use either a tooling joint or a wooden stick to shape them.
After the mortar has had time to set, be sure to go over it with a masonry brush to remove any additional debris.
From here, it’s just a matter of cleaning up your worksite and letting your new wall or outdoor feature set. For more information on installing Cultured Stone outside your home, be sure to contact our talented design team!