From deck stain, house paint and hiking boots to car wax, catfish, nail polish, filet mignon and masonry buildings, we apply coatings and sealants to myriad products for many reasons. Some are protective. Others are for achieving a desired aesthetic or strengthening the underlying material. Many preserve and strengthen a product and enhance the appearance. Coating catfish in cornmeal and spices is all about taste, and brushing mayonnaise on a fine cut of steak, along with quick high temp browning, is reputed to seal in flavor.
In the world of masonry, nail polish and mayonnaise will never work to seal against moisture or protect bricks, stucco and concrete masonry units (CMUs) from deterioration or graffiti. Brilliant minds in scientific laboratories have developed a variety of protective products which combine polymers, silicone and other things. Early silicone elastomerswere developed by chemists seeking improved insulation materials for electric motors and generators, with labs at General Electric and Corning Glass leading the charge.
The technically correct term for the different silicone rubbers is polysiloxanes or polydimethylsiloxanes. Then there are silanes, silcates, siliconates and all the connecting prefixes, suffices and root words like poly, tetra, oxy, chemical and molecular references and very long words beyond the scope of this article.
The main purposes for wanting to coat or seal a brick or concrete facade or horizontal surface include to:
- Prevent efflorescence
- Reduce fading from UV rays
- Eliminate graffiti opportunities
- Ward off mold or mildew growth
- Avoid moisture penetration
- Limit cracking from freeze-thaw climate cycles
- Create a high gloss, satin or matte look
Whatever product one chooses to protect masonry walls, floors, driveways, etc., it is imperative to start with a very clean surface. “It is vital that mason contractors work on a clean and dry substrate. If grime or atmospheric soiling is present, it must be removed prior to the coating or sealant application,” states Diane Phelan, LATICRETE Product Manager. “STONETECH KlenzAll™ Cleaner, for example, is recommended for use as it easily powers through stubborn grease and soils to help prepare the masonry surface. Additionally, mason contractors need to understand product usage and carefully follow the product manufacturer’s instructions to ensure a successful installation.”
LATICRETE is located in the small town of Bethany in southeastern Connecticut, population 5,539 [2010 census]. It is a third generation, family-owned firm started more than 60 years ago. Today, it is “a customer-focused, worldwide manufacturer and marketer of green flooring and facade materials, used in residential, commercial and industrial applications. Architecturally specified and professionally endorsed, LATICRETE offers a dedication to quality that results in globally proven solutions for virtually every flooring, waterproofing and facade application.” [laticrete.com] The company boasts 1,500 employees and a presence in 100 countries and on every continent.
Among the decisions in which product to use are:
- longevity
- budget
- application process
- masonry material
- surface condition
- aesthetics
- porosity
- access
- overall expectations
Coatings
A coating or “film-forming sealer,” like paint and car wax, is not formulated to penetrate, but to establish a barrier on the surface. Coatings are often preferred for aesthetic results, enhancing the natural color of pavers, for example, and come in different levels of sheen. “Dirt layered on exposed masonry surfaces retains water – and that encourages deterioration. Freezing and thawing, acid rain, stains and chemical reactions break down masonry surfaces. Stop the disintegration with Diedrich Technologies water-repellent products that also reduce bonding of airborne dirt and hydrocarbons. These products keep the building structure intact to protect your investment.” [www.diedrichtechnologies.com]
Coating products for vertical or horizontal surfaces fall into three basic categories:
- acrylic
- polyurethane
- epoxy
Acrylics are the most economical and quickest product to apply and dry, but the thin film they create on the surface is not known as long-lasting. They can be used inside or outdoors and can enhance the appearance of concrete, which is colored, stamped or contains exposed aggregate. They may require regular maintenance of wax applications or a sacrificial floor finish because they wear down and can show black heel marks and other stains. For outside spaces, the solvent-based product most often outperforms a water-based acrylic. Good for approximately one to three years.
Polyurethane was developed in the 1930s and is very common in home furnishings, as well as concrete and brick sealant. Flexible polyurethane foam contributes to furniture’s durability and comfort. As a floor sealant, it performs well over wood, concrete and brick, adding beauty to countertops and exposed aggregate or colored or stamped concrete. It is especially beneficial in high-traffic areas. Its coating is almost twice as thick as acrylic, and the result is a more durable, abrasion-resistant finish. It is good for interior and exterior spaces and must completely cure without any moisture to develop an excellent water-resistant bond. Check product for lifetime.
Epoxy is the Cadillac of coatings for its thickness and exceptionally hard, long-wearing properties. Like the higher class of coating and sealing solutions, it comes as two products, which need to be blended before application to specific directions for quantity of each. It is limited for interior use because UV rays will cause it to yellow. It can be ordered in colors, and most epoxies have a glossy finish. Because it is remarkably water resistant and some are totally impermeable, water can be trapped in the concrete it is protecting if water is present when the epoxy compound is applied. These also may be slippery when wet and require an added traction product for safety. Most epoxies will perform well for five to seven years.
Diedrich Technologies, headquartered in Schenectady, N.Y., is a division of Hohmann & Barnard, Inc., and is dedicated to revolutionary products to protect new and historic masonry construction. Roadways need attention as much as buildings. Among its extensive product lines is Salt-Bloc Chloride Barrier for concrete and pavers. While ideal for horizontal surfaces, the product is used on bridge pilings, retaining walls and other vertical structures. In addition to its water-repellent quality, Salt-Bloc blocks the absorption of chloride ions from de-icing salts and protects against chemical invasion of chloride salts, which can negatively impact rebar and wire mesh.
Southern Stain and Seal promotes its Seal-n-Lock SuperWet water-based urethane as the next generation in coatings technology. Not only does it boast, “a safe, low VOC, water-based formula, but it actually works! This is something we have never been able to say about any exterior, film-forming, water-based product before. On pavers, SnL SuperWet provides a rich enhanced color and wet look, along with superior stabilization of the sand joints. This unique formula can be used on damp surfaces without the risk of turning white like cheap solvent-based acrylics. SuperWet has very low odor and applies quickly and easily by sprayer, eliminating the need for rollers, respirators and toxic solvents.” [www.southernstainandseal.com]
“STONETECH® Heavy Duty Exterior Sealer [from LATICRETE] is made up of a solvent-based formula that provides optimal water repellency and weather resistance to natural stone and masonry surfaces,” relates Phelan. “This product can be applied at any time to maintain the surface, provided the masonry is clean and dry.”
Volunteer firefighter Brett Oakley was thinking outside the box when founding his company, Mar-flex, out of his concern for families, which could not escape their homes during disasters. His compassion paired with innovation brought a commercial waterproofing system named the Armor Series to market. It delivers superior water-based and solvent-based membranes with a focus on LEED certified products.
Sealants
The sealants product category delivers a wide range of cutting edge technology, state-of-the-art chemistry and innovation in the penetrating versions of water-resistant sealers. Even highly advanced nanotechnology has infiltrated the sealer market. While the goals are the same as coatings – to protect a surface from water, dirt, salt and seepage into masonry material – the sealants can have superior properties for their ability to impregnate concrete, bricks, pavers and mortar seams.
Some of the primary kinds of sealants are:
Penetrating– soaks into concrete, very long-lasting, can add second coat without having to remove the first one, high VOC, more sheen, breathes
Silane– recommended for high density material with smaller pores, could stain or darken appearance if any oil is present
Siloxane– very good penetration for highly porous surface, shallow impregnation
Silcate– forms a permanent non-soluble chemical bond with concrete, polished look, radon sealer
Siliconate– excellent multi-purpose sealer, can apply any time (on new or cleaned concrete), combats freeze-thaw sequence, prevents moisture seepage, water-based will not alter appearance of concrete
Untreated concrete invites water, dust, salt and harmful particles into its pores, so a penetrating sealer is the optimal product to enhance its density and protect its form. High performance penetrating sealers work behind the scenes for having penetrated into brick, CMUs and mortar. Most also result in a natural sheen, preserving the color and aesthetic appearance initially sought when choosing the masonry product. Many are also guaranteed not to flake or peel. Each manufacturer will have its own specifications. Brick sealers are very popular for reducing the occurrence of efflorescence.
“The latest advances in nanotechnology and innovative chemistry are what drive the Ghostshield® brand creating the most robust, supercharged and highest performance formulas in the industry. Having been a leader in underground waterproofing and directly involved with DeNeef Chemical, acquired by W.R Grace & Co. in 2011, our experience ranges across the globe.” [www.ghostshield.com]
Nanotechnology is working with miniscule particles impossible to see with the naked eye. The prefix “nano” means one-billionth. A grain of sand may measure around 500,000 nanometers, yet Ghostshield particles are small enough to pass through it.
Kretetek Industries, based in Hudson, N.H., developed the Ghostshield® product line and its experience reads like a Who’s Who of construction, including the Big Dig and Channel Tunnel. One its most amazing accomplishments is 432 Park Ave. “It’s the tallest residential building in the Western Hemisphere, an iconic super structure,” states Josh Moore, manufacturer’s rep for Ghostshield®. “It used 700,000 cubic yards equating to 350,000 square feet of concrete with 2,000 gallons of Ghostshield® Iso-Tek 8501 concrete sealer.” It is one of several examples of what he dubs “Ghostshield® in the field.”
Graffiti Protection
Graffiti comes from the Greek word “graphein” meaning to write. It is not cool, not art and not acceptable. In fact, it’s vandalism, which is a crime. It is expensive to deal with and hurtful to businesses and neighborhoods. The faster it is removed, the less likely repeat incidents occur. But the best protection may be coating buildings with products to which graffiti does not typically adhere.
There are a couple of approaches to graffiti prone areas. One is a sacrificial kind of coat, where a thin film is applied, which can then be peeled off and washed with a high pressure washer which removes both the membrane and the graffiti. The other is a protective surface to which neither marker nor spray paint can stick.
“Topical coatings or film-forming sealers act as anti-graffiti products as they provide a surface barrier,” Phelan explains. “If tagged, these coatings easily strip off to remove the defaced area. The product can then be reapplied to maintain surface protection.”
Film-forming sealers like Diedrich Technologies’ 333 Omegaseal “work well to protect against graffiti penetration and can be applied with a dense, soft masonry brush, roller or lower pressure sprayer, even a garden sprayer. Two coats are recommended with a 24-hour drying period between them.” [diedrichtechnologies.com]
PROSOCO is a national manufacturer of products for cleaning, protecting and maintaining concrete; making building envelopes air-tight and water-tight; and cleaning, protecting and restoring new and existing masonry buildings. Its Sure Klean®Weather Seal Blok-Guard®& Graffiti Control is a clear, solvent-based silicone elastomer formulated to weatherproof custom masonry units, cast stone, architectural concrete block, precast concrete and other porous masonry materials. Seal Blok-Guard® & Graffiti Control protects masonry surfaces from repeated graffiti attacks without altering the natural appearance.
Once you have defined your purpose and desired result for coating or sealing a building, you have a plethora of products from reputable manufacturers to consider. The bottom line is that coating or sealing any masonry structure is smart and sensible for long-time preservation and natural beauty.
Joanne M. Anderson is a nationally-published freelance writer and author who resides in Southwest Virginia. www.jmawriter.com