Maintenance Issues With Stone Veneer

Base Wall Conditions

• The wall on which stone veneer will be applied must be clean and have no paint or finish. Otherwise, mortar will not adhere to the stone finish. Placing mortar on a wall not prepared properly provides a substandard hold for the stone. A metal lath should be applied to a wall that is painted or has a finish. Then mortar is applied directly to the lath. Sometimes homeowners or amateur installers skip the lath step and apply mortar to a painted wall, causing poor adhesion and a shorter life for the stone veneer.

Mortars

• Often stone veneer includes specially made mortar. In some cases, homeowners use a more generic mortar to hold the stones. That can be acceptable, but some mortars are better than other mortars. The veneer usually is made from cements and natural materials such as wood. The mortar used must be specified for those materials. Bonding to real rock or brick is not the same as bonding to a synthetic compound such as stone veneer. Poor mortar leads to a wall that lacks structural integrity. Even if the mortar is up-to-grade, manipulating, moving or cutting the set stones before the mortar dries can lead to structural problems later. After the stones are set, they needs to sit still. When the mortar dries, it can be shaped and excess mortar cleaned away.

Sealants

• Applying a waterproof sealant after installation protects stone veneer walls, and maintenance problems result from sealants that are not designed to adhere to synthetic rock. Silane- and siloxane-based concrete sealers are examples of sufficient sealers. Without a sealer, water, smoke or other damage could occur. Regularly applied coats of high-quality silane sealant is necessary for outdoor stone veneer in cold regions. It should be retouched every few years to prevent frost damage.

Weather

• Weather is the most important non-installation issue for faux stone. Problems increase for outdoor stone veneer walls in cold regions, particularly those with a wide gap between summer and winter average temperatures. Exterior stone veneer in areas that range from freezing in winter to sweltering in summer needs sealing every year, or at least in accordance with its manufacturer's instructions. The sealant instructions differ among manufacturers because they use different compounds.

  Using particular products on stone veneer, such as certain chemical ice removers, may void its manufacturer's warranty. Nearly all stone veneer manufacturers warn customers against using chemical cleaners on their product.