Cultured stone. Manufactured stone. Real Stone. There are a lot of options when it comes to using stone as an exterior cladding. For this article, we are going to concentrate on manufactured or “cultured” stone.
Installation: Manufactured Stone Veneer, (MSV), is a man-made product that is available in a variety of sizes, styles and colors. MSV is one of the most aesthetically pleasing exteriors. It can be used with stucco, brick or cement board siding as an accent, complete wall or, if the budget allows, can be used clad the entire home.
As with stucco, manufactured stone is not without its issues. It is installed in the same manner that a stucco system is installed.
Layer 1: There must be proper plywood or OSB sheathing over 2X4 or 2X6 framing.
Layer 2: There must be a weather barrier. This barrier SHOULD be a liquid applied waterproofing membrane. We use StoGuard. This is far superior to Tyvek or building paper.
Layer 3: After the waterproofing is applied, we install a slip sheet of building paper. This protects the waterproofing from being scratched when the metal lath and accessories are installed.
Layer 4: Then comes the metal lath and the cementitious scratch coat.
This is the exact same procedure for stucco and stone. After the scratch coat we then begin to install the stones. They are light weight and come in different shapes and sizes OR panels that give an appearance for a specific type of stone lay. There are stones to form sills, trim pieces, borders, grouted stone, stacked stone, ledge stone, cobblestone. They are “kiln dried” after coloring and easily breakable. To install this product, it is very time-consuming and the product itself is extremely expensive.
MSV is now becoming front and center with moisture intrusion issues and is installed exactly the same as a stucco system. This means that installation errors, improper flashing, lack of weather barrier, sealants that are not maintained, cracking or missing stones can all be a contributor to water getting to the substrate.
Maintenance: Proper maintenance will be required and includes inspecting sealants wherever the stone terminates to windows, door, and penetrations. Penetrations are outlets, hose bibs, flashings, number plates, etc.... If water gets in, there is a potential for intrusion issues.
Check to see stone has not fallen off. This is a typical occurrence with a stacked-type MSV. If there are stones that release from the wall, it is important to get those reapplied. Check for excessive cracking to maintain waterproofing and structural integrity.
When purchasing a home with MSV, it is extremely important to have the stucco inspector do a moisture inspection of the MSV and verify that they will conduct the probe behind the stone. If the inspector tells you that he cannot test, call another inspector!
Repairing and Reinstalling MSV: this is very important to understand, if we must remove MSV to conduct a repair, there is a good chance that we will not be able to salvage all the pieces. Since the stone is man-made and it has been cementitiously attached to the wall, breakage is typical and expected. Knowing the manufacturer and style of MSV will help in targeting a replacement stone.
MSV is very expensive and when we order stone, we are limited to the quantities that we can buy, meaning, we can’t simply buy two or three pieces. There are minimum quantities that are required. In addition, we are reliant on the manufacturer in what types of stones are in the lots that we purchase. Unfortunately, we cannot specify colors, shapes, or sizes, but we will do our best to get as close as possible to the stone that exists on your home.
Regarding the above paragraphs, it may be necessary to remove a larger section of stone to make the match look better, and to also make the pattern look more pleasing.
Step 1: The stone comes off the wall and we will salvage as much as we can. From this point we treat the wall as we would with a stucco repair. Using a diamond cutting blade, we will cut through the cement to expose the substrate underneath. Care must be taken to ensure that we do not damage any surrounding stones that have been left in place. Vibrations can be detrimental to the stones in place.
Step 2: When the wall is exposed, we will simply follow normal protocol and remove and replace all the plywood and framing that has been damaged by water. We will then apply our StoGuard, liquid-applied waterproofing membrane, all it to dry, protect it with a slip sheet of building paper and attach the metal lath, (the chicken wire that holds the cement to the wall). After the lath is installed, we will apply the scratch coat of cement, (the only coat of cement). Typically, we will use a fast-setting base coat to not delay your project.
Step 3: Installation is time-consuming and requires much thought. Putting stones on the wall is like doing a puzzle, sometimes you must work through many pieces to find the one that fits perfectly. Sometimes we lay the pattern out on the ground before putting it on the wall. Every stone has its place, and our expertise allows us to provide the outcome our customers are looking for.
Step 4: Once the stones have been attached, they must dry properly before we can finalize the project. We need to ensure that there are no loose stones, especially if this is a stacked stone. If your stones require grouting, we will conduct the grouting process and then move to cleaning up the job site.