Sealants for Formed Stone

Formed Stones

• Both homes and businesses can incorporate formed stone designs. Formed stones — also known as paved stones — consist of natural or manufactured stone materials, such as limestone, flagstone, slate and brick, set inside a sand mix. Stone layouts appear in an assortment of patterns and styles as seen on residential patios, walkways and town square courtyards. The materials that make up formed stones can withstand foot traffic and weather effects much like the natural stone materials found in nature. Sealant applications provide an added layer of protection for stone interior and exterior surfaces.

Topical Sealants

• Topical sealants are a type of sealant application that forms a protective coating on formed stone surfaces. Topical coatings consist of a mixture of plastic materials, acrylic and natural wax. These ingredients form a protective barrier against liquid materials, such as oil and water. In terms of durability, topical sealants come in two categories, known as strippable and permanent. Strippable sealants contain water-based compounds, such as styrene and acrylics, that allow for easy removal, or stripping. Permanent sealants — also water-based in content — may consist of polyurethane or epoxies, which make for a permanent coating on stone surfaces.

Impregnators

• Sealants capable of repelling liquid materials fall within the impregnator category of formed stone coatings. These sealants penetrate below stone surfaces, allowing them to repel liquids as opposed to the barrier effect created by topical sealant coatings. Impregnators use a solvent- or water-based polymer solution that allows stone surfaces to breathe and release vapor buildup. Different formulas work to repel either water-based liquids, such as sodas and coffee, or oil-based materials, such as grease and body oils. Sealants designed to repel oily materials can also repel water-based materials. As formed stone designs can decorate kitchen countertops and cooking surfaces, impregnator sealants help to protect stone surfaces from cooking splatters and food spills.

Considerations

• As topical and impregnator sealants serve different purposes, one may be more suitable than the other depending on the location of a formed stone layout. Since topical sealants form a protective coating on stone surfaces, these sealants can cause damage to exterior stone work when moisture gets trapped inside the stone. Topical sealants also tend to scratch and scuff more easily than impregnators, so frequent applications may be necessary.

  In the case of impregnator sealants, their strong repellent properties can produce flammable vapors when applying sealant to stone surfaces. Once dried, these sealant types also release environmental pollutants — known as volatile organic compounds — into the air. As a result, some state laws have restricted the use of impregnator sealants.