Installing manufactured stone on the exterior of your home is the latest design rage. It can really add some major flair to an otherwise boring design. But at $18 to $20 per square foot for installation, it’s critical to get done right the first time. So what are the most important points to consider when installing manufactured stone on the exterior of a home?
Water Resistive Barrier
It’s extremely important to install a water resistive barrier between the stone and the face of the home. This barrier will keep moisture from getting into the wall cavity and destroying the structure. One of the simplest vapor barriers is a roofing felt. Typically, two layers of 15 lb. felt paper are used. Several other options are available on the building materials market so check with your architect or local building department for the best choice for your project and location.
These are installed over any openings in the wall to prevent water from getting into the wall cavity. Flashing materials should be installed over all windows and doors. The top of these flashing should terminate up under the water resistive barrier and adhere to the face of the home.
If you are installing manufactured stone over a framed wall, it will be necessary to use a metal lath over top of the vapor barrier. This lath is typically stapled to the front wall of the home and is made of a corrosion resistant material. Galvanized nails or staples should be used to secure the lath to the home.
After the metal lath is installed, a scratch coat of mortar, type N or S, is installed around and over top of the lath. The purpose of this surface is to provide a solid bond between the stone and the house. The scratch coat should be installed at a thickness of about one half inch. Once the mortar thumbprint hard, the surface should be scored to provide a surface to adhere the stone to.
Prior to installing stone, the scratch coat surface and the back of each stone should be moistened. Then, each stone is buttered with one half inch of mortar. The mortar should cover the entire back side of the stone. Then each stone is pressed into place on the wall. Ideally, installation will start at the top of the wall to prevent splatter of mortar droppings on the stone below.
It’s extremely important to read and follow all stone manufacturer recommendations. Each product has specific characteristics that require certain tweaks to the installation.
Installing manufactured stone can be a great way to enhance the look of your home. And with the proper installation techniques, it will stand the test of time.