Q: What are some of the reasons fabricators should seal/impregnate a countertop prior to installation?

By offering an added value service, the fabricator is put into a different light during the sale. Sealing a countertop is adding value to the service.

Countertops are coming under attack all the time. Products such as Silestoneâ„¢ are sold as anti-microbial. Even setting and grout manufacturers are adding components to make the products resist bacteria, fungus and even mold. There is clear independent testing available to show how a tile or granite surface can only effectively repel certain bacteria if the appropriate impregnator is used. In fact, sealing with the appropriate impregnator can be a great selling benefit for the fabricator, particularly when they are selling stone countertops against manufactured surfaces such as Corianâ„¢, Formicaâ„¢ and even steel.

There are some impregnators/sealers that are approved for use on food surfaces by such agencies as the USDA. In addition, many manufacturers have independent testing concerning bacteria as well.

Because of the coverage/spreadage of many impregnators, the cost of application for the fabricator is pennies per square foot. There is no good monetary reason for a fabricator not to seal/impregnate the surface.

Sealing the countertop also opens an opportunity to sell add-on products in the future. Many fabricators even give gift bags and boxes of maintenance products to the owner with a nice note, “When you run out of care products, please come by the showroom for more.” Why should a fabricator's customer go into a hardware store or grocery store to purchase maintenance products, if the fabricator who sold them the counter stocks the appropriate products? And while they are in to buy the maintenance products they are looking at everything in the showroom, not just care products.

Another consideration is the “peace of mind” factor. There is no question that sealing can give the fabricator peace of mind that the installation will be easy to maintain and will ultimately be a better installation because of it being sealed.

Q: What are some of the things a fabricator should know when they are sealing the countertop in the shop?

Know the stone and the product you are using. Read all labels, product data sheets, care guides and material safety data sheets. Conduct several tests to make sure both the sealer/impregnator and the substrate perform to the desired expectation. Know the difference between a water-based sealer and a solvent-based sealer and the issues each has with application, such as surface absorption, temperature of application, product evaporation rate, cure time, residue removal, application techniques, etc.

Q: What methods of application can be used?

Products can be applied in many ways, but usually the best method is using a clean terrycloth, and wet the surface to the eye. Allow the sealer/impregnator to sit 3 to 5 minutes, and wipe all excess off. Allow the sealer to cure 12 to 72 hours before using. If the product dries on the surface, usually buffing with a #0 or #1 steel wool pad will remove the residue.

Q: Should there be a designated area for applying a sealer?

Typically, the products can be applied almost anywhere, but if solvent is being used, then good air ventilation is necessary.

Q: How should the sealing products be stored?

Keep the products capped tightly to avoid contamination. Store them in an upright position in a cool dry area and avoid excessive heat or cold. Some water-based products will freeze, and some solvent-based products are extremely flammable, so know what you are dealing with and store per the manufacturer's instructions.

Q: What is the typical shelf life of a sealer?

Shelf life of a sealer will vary from manufacturer, but 12 months is most common - if stored in a non-contaminated environment.

Q: After installing a sealed/impregnated counter, how should the fabricator convey a maintenance program to the homeowner? What about past and future treatments?

Most every manufacturer of sealers has a specific “Care Guide” for countertops and for the various substrates as well. Typically, all the fabricator has to do is hand the customer some “Care Guide” literature with their gift pack. This literature will refer to re-treatment periods as well as what to use to clean, polish, disinfect and even restore the stone.

Q: Will the color change from the time the homeowner picks a slab to after it has been sealed/impregnated? Will the color of the sealed/impregnated countertop change over time?

Most impregnators will not alter the color appreciably, and if the entire surface were treated, any color change would be slight and very hard to notice. There are many other items that

discolor the surface long before the sealer/impregnator is applied, however, because the sealer/impregnator is usually the last product applied, it gets the lion's share of the blame. Plumbers' putty, adhesive, grout, household chemicals and other products can all contribute to the discoloration of a stone countertop.

The color of the stone will not change over time due to any phenomenon created by the sealer/impregnator. It may change due to the characteristics of the stone, installation, location, maintenance, etc.