FAQs
Frequently Asked Questions
Interior: Product Application FAQs
Interior: Product Selection FAQs
Interior: Surface Preparation FAQs
Interior: Troubleshooting FAQs
Exterior: Product Application FAQs
If you need to paint outside with latex paint when temperatures are moving up and down like a yo-yo, I suggest you use one of the latex like Duration, Resilience, or SuperPaint. These products can be applied and will cure at lower temperatures, as low as 35° F. Traditional latex-based paints need temperatures above 60° F to cure properly. Warmer temperatures are needed to allow the latex particles to coalesce, or melt together. That is why the spring and fall can be tricky times to paint outside.
A common mistake is to paint when the daytime high temperature gets above 60° F and the nighttime temperatures get much cooler because dew forms on almost everything as soon as the sun goes down. Even though the temperature was OK at the time of application, the paint can stop coalescing. This permits moisture to get into the uncured paint film allowing certain ingredients to come to the surface when the moisture evaporates, causing surface staining and possible adhesion problems.
Rolling is usually the best method. Consult the Product Datasheet for specifications and recommendations on this. If applying by airless, you should use .021 to .031 tips because this is a fairly heavy-bodied material. When working with a low-texture material, the spray unit must be specifically designed for aggregate coatings. Generally, you can spray on 20 to 30 wet mils by cross coating (a horizontal coating pattern followed by a vertical coating pattern). When rolling, almost invariably a minimum of two coats will be needed to achieve the acquired film thickness. When applying over flat surfaces like poured-in-place concrete, simple spraying works well. When applying over rough surfaces like stucco, spraying would have to be followed by backrolling. Backrolling involves an additional pass with a wet, but not loaded roller, that will force the material into contact with all dips and holes in the surface.
The key thing to consider when repainting aluminum siding is not the method of application, but the surface prep. Aluminum siding is normally painted only after it has faded and chalked. If the chalkiness is not removed, the paint will not adhere properly. Spraying will be much quicker than brushing, and as long as the proper tip size and pressure are used, it will produce excellent results. Duration, Resilience, or SuperPaint Exterior Acrylic, applied to a properly prepared surface will produce a quality long lasting finish.
Try not to paint too large of an area at one time. Overlapping occurs when a freshly painted section begins to dry before you start painting the adjoining area.
Exterior: Product Selection FAQs
As for leaving the stucco unfinished, only the manufacturer of the material can tell you what effect a winter's weathering would have on it. Loxon Exterior Acrylic Masonry Primer is the correct primer for new stucco. It cannot be used below 50° F. A-100 is a topcoat that is meant to be applied down to 35°F, yet not meant to be applied to fresh, hot, masonry surfaces.
Gloss paints are best for paintable shutters and trim because they accentuate architectural details and their finish tends to be hard and smooth.
Hardboard siding is manufactured by pressing a mixture of wood chips, binder and wax into shape and embossing with a wood grain pattern. Most of this siding is then factory-primed before shipment. To provide proper adhesion and to prevent wax staining, we recommend applying a quality alkyd-based primer before topcoating, whether the siding is preprimed or not. Once the alkyd primer has been applied, you can use either an acrylic latex or alkyd topcoat, depending on the customer's personal preference.
First, determine that the roof is indeed tin, and not galvanized steel. If it is tin, clean and rinse the surface to remove any dirt, mildew or surface contaminants. After the roof is dry, apply a slow-drying, rust-inhibitive oil-based primer followed by two coats of a quality topcoat. Industrial-grade acrylics, slower-drying alkyds and aluminum paints can all be used for the finish coats. If the roof is galvanized, make sure it is clean, dry, and sound and then apply a primer like DTM Primer/Finish, following with two coats of DTM Acrylic Finish. Use a conventional roof coating material if the roof is flat.
Vinyl siding is a very flexible material that expands and contracts horizontally with temperature changes. In fact, when it is installed, the nails are not hammered all the way into the sheathing to allow for such movement. Since dark colors absorb more heat than light colors, painting the siding brown could cause it to flex so much that it could come unfastened or, in severe cases, even cause structural damage to the house. A good rule of thumb is to avoid using a paint color any darker than the original color of the siding unless the coating is specifically designed for such use Like Sherwin-Williams VinylSafe Technology.
Both ideas are correct. Since moisture is the culprit in many cases of exterior peeling, it's important to use a good quality, acrylic caulk to fill gaps around windows and doors, joints in siding and trim boards, and anywhere moisture could get into the end-grain wood. However, you also need to make sure that moisture generated inside the house has a way to escape. The best way to "allow a house to breathe" is gable, roof, and eave vents. If you are correcting an existing moisture-related peeling problem, you may also need to install siding wedges or vents to give the moisture an easier path of escape than through the paint film. Caulking where the siding overlaps is not advisable, as it could trap moisture behind the paint, causing it to peel.
In many cases, the application of a high-solids universal primer or barrier coat will allow the application of a strong solvent-based epoxy or urethane over a previous coating. Using a barrier coat reduces the likelihood of the solvents in the topcoat lifting previous finishes and eliminates the need for costly and time-consuming removal of all existing paint.
Stay away from conventional floor coatings such as epoxies and alkyd floor enamels. While an epoxy would withstand the exposure to the pool water, both of these types of paints would be far too slippery to use around a pool. Since the concrete is new, an acrylic concrete coating like Sher-Crete Flexible Concrete Waterproofer would be your best choice.
After allowing the galvanized surface to weather for six months or chemically cleaning it to remove any oil or remnants of the galvanizing process, you can apply two coats of an acrylic latex paint directly to the metal or a special galvanized metal primer topcoated with an alkyd or latex product. Do not apply an alkyd directly to a galvanized metal surface because the oils will react with the zinc used in the galvanizing process, causing the alkyd to peel.
Exterior: Surface Preparation FAQs
It is not a good idea to caulk the lap on your siding. To do so could trap moisture from inside the home behind the siding, causing it to come out through the paint, resulting in peeling.
Stains caused by rusted nails will bleed through the topcoat of even the most durable paints unless a stain-resistant solvent-based or acrylic latex primer has been applied first. If you are painting new exterior construction where non-galvanized nails have been used, it's advisable to spot-prime the nailheads and any knots in the wood prior to applying the topcoat.
If the old paint is peeling, take a good size piece of the peeling paint and hold the edges of it between your thumb and index finger. Exert pressure on both sides of the chip. If it is very flexible and bends easily, it is probably latex. If it is hard, brittle and breaks instead of bending, it is most likely oil-based paint. Another way to test the paint is to wet a rag with denatured alcohol and rub the surface of the paint. If the paint softens or rubs off, it is most likely latex. An alcohol test usually will not affect an oil-base paint.
A primer is beneficial because it helps provide a uniform surface that promotes good adhesion of the topcoat. A primer can also serve a special purpose by sealing a porous surface, blocking out stains, preventing rust formation on iron and steel, and preventing tannin bleed on wood. Most finish paints are designed to provide a decorative or protective finish for a substrate. In most situations, they do not provide the features of a primer, so it is always important to follow the manufacturer''s recommended coating system.
Fisheyes are caused by some type of surface contamination that was not removed in preparation for painting. This contamination can be from body oils, silicone from furniture polish, or any greasy or oil substance. The slippery deposit on the surface does not allow the paint to adhere, causing it to shrink away from the contamination and form a dimple-like void in the paint film.
Try using a solution of one quart household bleach in three quarts of water. Apply the solution to the area with mildew and then rinse off with water. Never add detergents or ammonia to the bleach/water solution. Always protect your skin and eyes against splashes.
If it is not practical to allow the surface to weather for six months before painting, it must be cleaned with a solvent to remove any surface contaminants and oils applied by the manufacturer to prevent oxidation of the zinc in the galvanized coating. This is best accomplished by using a water-soluble degreasing cleaner applied with a clean cloth or sponge. Change sponge or cloth and cleaning solution frequently so the dirt and oil are removed from the surface, not just spread to other areas. Rinse the surface thoroughly and allow to dry before painting.
Until recently, you had to wait one to two months for the stucco to cure properly. However, new-generation masonry primers speed up the process considerably. For instance, Loxon Exterior Masonry Primer from Sherwin-Williams can be applied as soon as the stucco is hard, dry and at a pH level of less than 13. After the primer dries, you can follow with latex house paint immediately.
Handle it the same as you would a regular stucco finish. Loxon Exterior Masonry Primer can be applied as soon as the stucco is hard, dry and at a pH level of less than 13. After the primer dries, you can follow with Duration® or Super Paint. The small glass particles should be imbedded into the stucco enough that they shouldn''t bother the adhesion of the new paint.
No, as long as the siding has had a chance to weather a year before painting. You do need to clean the surfaces first with an Extra Strength Cleaner Degreaser. You want to be sure the surfaces are free of chalk and residue.
Exterior: Troubleshooting FAQs
You should prepare and repaint the entire window unit. Begin by removing all loose paint with a wire brush or scraper. Don't forget the ends and underside of the sill, as peeling or cracking often begins there.
Next, remove any old caulking from the joints in the frame and the areas where the frame meets the sill and where the frame and sill meet the siding. Finish the surface prep by sanding the wood until it has a bright, new look. This removes any decayed wood fibers from the surface and provides a sound surface to paint.
Now apply one coat of A-100 Exterior Alkyd Wood Primer, again paying special attention to the end grain and underside of the sill. After the primer dries, apply an acrylic latex caulk to the joints in the frame, the space between the frame and sill, and the space between the window and the siding.
Follow with two coats of a top-quality acrylic latex satin or gloss house paint, like SuperPaint. After you replace the storm window, make sure the drain holes at the bottom are open. This will prevent the condensation that builds up on the inside of the window from collecting on the sill.
No. Paints can be formulated to inhibit mildew growth, but under some conditions, mildew eventually will reappear on any type of paint.
The eaves of a house are a frequent location for paint problems, with peeling topping the list of concerns. Moisture drawn out of the house sometimes is the source of the problem, but more times than not the culprit is lack of inter-coat adhesion. This occurs when paints are applied to old, hard and glossy paint films and when dirt and contaminants, such as salt, is not properly removed prior to painting.
Ultra-violet radiation from the sun causes wood to naturally darken. For wood surfaces that have never been coated, or which have been finished with clear varnishes or lightly pigmented stains, this darkening can be unattractive.
When paint is applied in excess of the recommended wet film thickness or when two coats of paint are applied too quick. This will not allow sufficient drying and wrinkling may occur. This surface imperfection should be corrected once the paint film has dried by power sanding. The smooth area should then be primed with a quality oil or latex primer prior to topcoating.
When dew forms on latex paints before the film has fully cured, a concentrated residue from the paint material can form on the surface, causing staining, unsightly runs and gloss patterns. This finish problem is known as surfactant leaching. Aluminum siding is particularly prone to surfactant leaching because this type of substrate reacts to temperature changes faster than wood. To avoid this problem, apply paint during temperatures that allow proper curing. Avoid painting during hot and humid days with significantly cooler evening temperatures.
Stucco and mortar joints contain hydrated or "hot" lime, a dry compound added to improve the workability of these materials. If the high alkalinity of mortar, cement mixes and concrete is not addressed prior to painting, a reaction can occur when moisture is present, resulting in blistering, peeling and burning stains.
The culprit here is a water-soluble dye called tannin. Moisture in the wood will cause the tannin to migrate to the surface and stain the paint. New red-colored wood must be sealed with a quality alkyd or latex undercoater to create a barrier between the topcoat and the wood. More severe cases of tannin bleed may need one or two coats of an alkyd primer to prevent discoloration.
Latex paints contain chemicals called plasticizers that allow proper film formation and keep the coating flexible. Many vinyl and plastic weather-stripping materials also contain plasticizers to give them flexibility. When two surfaces containing plasticizers come in contact with each other, they can have the tendency to stick. This condition, known as blocking, will generally occur during the early curing time of the coating, but it can continue for some time. Blocking can also occur on double-hung windows and garage doors. The easiest way to prevent blocking is to use a non-blocking acrylic, or alkyd base paint in areas where it may occur.
The deposits, known as efflorescence, are caused by moisture in the masonry. The moisture dissolves salts in the masonry -- the mortar, block, concrete, etc. -- and is drawn to the surface by the heat of the sun. The water evaporates, leaving behind white deposits that must be removed before painting. After you find and fix the source of the moisture, remove the efflorescence with a wire brush and coat the surface with a masonry primer and topcoat.
Cover Your Bases
"But that color doesn't look anything like the one on the chip!" Most painting contractors have heard a customer say that at one time or another. It's a frustrating dilemma, and especially common with transparent, deep or vivid colors. But you can easily solve it by using a tried-and-tested color palette along with the right basecoat whenever color is important to your client. (And when isn't it?)
The Sherwin-Williams exclusive Color Prime System is a continuum of gray shades that starts at light gray (P1) and gradually deepens to P6, or the darkest gray. This technology is based on how color pigment scatters and absorbs light.
A primer tinted to the recommended shade of gray creates the ideal balance of light absorption and scattering to achieve the correct color in fewer coats. By working inside the color space of the topcoat color, the right basecoat shade allows the topcoat to more fully and more quickly develop its true color.
Bottom line: You'll achieve true color faster and easier. And, you'll reduce the chances of hearing a customer complain about the color on the wall not matching the color of the chip.
Aldo Marini, owner of Interior Solutions in Cleveland, Ohio, says the Sherwin-Williams gray primer system saves time and money on his new construction residential projects.
"I work with a lot of decorators and high-end builders that have been specifying the deeper colors," he says. "In the past, it often would take us three coats to get the color right. My Sherwin-Williams sales rep knew that was concern for me, and introduced me to the Color Prime System about two years ago."
Using the gray shade primer system, he found, enables him to obtain the same quality results in just two coats. There's no guesswork, since he just has his Sherwin-Williams store add the gray tint specified on the Sherwin-Williams color chip to his favorite PrepRite primer. He will also use a gray-tinted Color-Prime Interior Primer when working with a ColorAccents topcoat.
"In the past, I had shied away from using ColorAccents on new construction, but Im not afraid of using the deep colors anymore," Marini says. "We get really good color accuracy by using the gray primers, and the ability to cover in two coats saves us significantly on labor."
For certain deep, vivid or transparent colors – about 20 percent of the Sherwin-Williams COLOR® palette – a gray basecoat is your ticket to:
- Achieving accurate color match in fewer coats
- Better touch-up
- Superior hide
- Deep, vivid accent colors that look bolder and brighter
- More uniform color, less streaking
- Eliminating guesswork
- Saving time and money
- Increasing customer satisfaction
Q & A: Household Mold
Mold is a rapidly reproducing microscopic fungus that feeds on decomposing organic matter.
Many molds are harmless, and are, in fact, a vital part of our ecosystem. But, if you've ever gotten food poisoning or suffered from allergies, you know that all molds are not benign. Some molds create toxins, which can seriously affect the health of plants, animals and people.
Homes make an ideal growing place for mold. Molds thrive in temperatures between 60° and 100° F, where moisture and an abundant food supply are present.
Yes. Building materials like drywall, gypsum wallboard, wood, adhesive, ceiling tiles, paint, plywood, paper and cardboard all contain cellulose, which is a source of food for molds.
They are similar but not the same. Mildew is a mold-like organism that feeds on organic tissues. In homes, mildew thrives on damp surfaces, especially in kitchens and bathrooms.
One good starting point is to use paints with anti-microbial properties, such as Sherwin-Williams Harmony and Duration Home.
Mold growing on non-porous surfaces can be cleaned with a detergent. But the affected parts of porous surfaces such as drywall must be completely replaced, and the area must then be cleaned thoroughly.
A semi-porous surface like solid wood, if infected, may require a combination of cleaning and replacing, depending on the severity of mold growth.
Sure. Some good steps are to seal ductwork, to allow for proper drainage of rainwater, and to exhaust moist air and allow fresh air to circulate indoors.
Not quite true. Only a few can cause health problems under certain conditions.
There are many molds that are black. But however threatening a mold may look, you cannot determine toxicity by color.
Certain kinds of mold have adapted to survive in almost any climate. But most flourish in temperatures between 60° and 100° F.
Actually newer builds may have more problems because their tighter insulation allows moisture to build up inside.
Bleach can control mold growth on surfaces, but often does not affect the source of the problem. Also, bleach should not be used on porous materials or metals.
- Allow for drainage of rainwater. Moisture that enters a building after a storm is one of the causes of mold. Roots, windows, exterior doors and walls should be constructed to allow water to drain to the outside of the structure.
- Exhaust moist air out of the building. Use exhaust fans in bathrooms, in kitchens above stoves, and wherever else moisture can build up.
- Seal ductwork. Leaky ducts allow cool air into buildings. When this cool air mixes with warm air, the dew point changes and water condensation is created. Also, leaky ducts can create air pressure imbalances. Both of these conditions make indoor moisture harder to control and lead to air quality concerns.
- Allow plenty of fresh air to circulate. Proper ventilation will help prevent mold and other indoor contaminants from building up in a house.
- Remove sources of mold. Clean mold growing on non-porous surfaces with a detergent. On porous surfaces like drywall infected surfaces must be completely replaced. Infected semi-porous materials like solid wood might require a combination of cleaning and replacing.
- Use Sherwin-Williams mold removing products such as:
Paint Quality
To your customers, painting is a major investment. In time. In money. In labor. You know it pays to spend a little extra to get a high-quality, long-lasting finish.
But what does “quality” mean? And what benefits do high-quality paints provide?
Bottom line: Better ingredients mean better performance. A high-quality coating starts with high-quality ingredients that allow paint to apply more easily, look better and last longer. Here are the four key ingredients that affect the quality of paint:
There are two different types of pigment that go into a can of paint. First are "prime" pigments.
These provide color and hide. Second are low-cost "extender" pigments. By comparison, they add bulk to the product, but have little value as it relates to color. Higher-quality paints have more of the all-important, yet more expensive prime pigments – all the things that in the end give you easier application as well as better durability and color retention.
There are a variety of binders used in today's paints. Latex paints contain either 100 percent acrylic, styrene-acrylic, or vinyl acrylic binders. Oil paints typically contain linseed oil, soya oil, or modified oils called alkyds.
The type, quality and amount of binder affect everything from stain resistance and gloss to adhesion and crack resistance. Higher quality binders, found in higher quality paints, adhere to surfaces better and provide enhanced film integrity and longer lasting performance. This makes them more resistant to cracking, blistering and peeling.
The liquid provides no added performance benefits. It's simply the "carrier" that allows you to get the paint from the can to the surface.
As you might guess, top quality paints have a greater ratio of solids (pigment and binders) to liquids, while cheaper paints are more "watered down" with liquid.
Additives are ingredients that give a paint a specific benefit that it might not otherwise have. Common additives in higher-end paints include:
- Rheology modifiers – provide better hide through flow and leveling of the coating.
- Mildewcides – keep mildew in check.
- Dispersing agents – keep pigment evenly distributed.
- Preservatives – prevent spoilage.
Additives do increase the cost of the product while providing significant added benefits.
We stand behind our paint quality, and so does third-party testing and research.
Victory Over Vinyl
Removing vinyl siding – while requiring careful and often extensive prep work – is a viable business opportunity for all painting contractors.
This time, it was personal.
Jim LeClair took one look at the 100-year-old Holland Home and grinned. His firm, Professional Painting, had just been awarded the contract to restore and paint the historic Boston house. Even better, the owner had agreed with his recommendation to remove the vinyl siding that had been installed 30 years ago.
“We were all really psyched about this job,” says LeClair, whose company has been doing residential work in the Boston area for 23 years. His current staff consists of four painters and one carpenter. “The vinyl siding craze hurt painters and paint suppliers alike. To remove the vinyl siding and restore the natural beauty of the wood and paint was a dream come true.”
He also wanted to show that removing vinyl siding – while requiring careful and often extensive prep work – is a viable business opportunity for all painting contractors.
“We were on this job for two months, and we landed seven other houses in the neighborhood as a direct result of the work we did there,” LeClair says.
Reason for painting
LeClair has now completed seven homes in which vinyl or aluminum siding was removed. Homeowners, he says, have a variety of reasons to return to the original painted look. Part of it can be pure aesthetics. Part of it can be resale value. Part of it can be homeowner concerns about PCBs, vinyl chloride and mildew. Part of it can be structural problems.
At the Holland Home, it was a combination of all four. When a previous owner decided on vinyl siding, the siding contractor had taken a few shortcuts to make installation easier.
“The vinyl guys had removed all crown moldings from the fascia and soffits,” LeClair says. “They removed the window trim and hacked off the sills to make it easier for them to wrap it. They also knocked off the eaves and soffit ends, closed in a porch and added three large picture windows without casings.”
Termite and carpenter ant damage was also discovered after the siding was removed. Bob DeCosta, Professional Painting’s staff carpenter, spent eight weeks rebuilding and repairing the wood and replacing shingles.
Three rounds of pressure washing (two with a bleach-water mixture, one with Sherwin-Williams ProClean Professional Prep Wash Cleaner) removed the mildew and mold that had grown beneath the vinyl siding. After priming with Sherwin-Williams A-100 Latex Primer, the paint crew topcoated the home with two coats of Sherwin-Williams Duration® Exterior Satin Coating on the white areas and WoodScapes Stain on the blue areas. SuperPaint Exterior Satin Latex was used on the blue trim. Because of the home’s moisture and mildew problems, they waited three days between coats and conducted multiple daily tests with a moisture meter and conducted random mil tests of both the wet and dry film.
“We use high-quality Sherwin-Williams coatings like Duration and WoodScapes for their superior coverage as well as for their ability to outlast the paint our competition was using,” LeClair says. “Our jobs typically last for eight to 10 years while painters using inferior products and methods are lucky to see their jobs last three years in the harsh New England climate.”
That kind of durability, of course, is a major selling point for homes in which the removal of vinyl or aluminum is a possibility.
“We took this big classic home and breathed new life into it,” LeClair says. “That is a very satisfying feeling.”
Coating Concrete for Color, Style and Protection
Cost-effective, sturdy, versatile – it’s no wonder use of concrete in commercial and residential construction is increasing.
One reason for the continued increase in concrete use is that architects and developers are discovering that this reliable old stand-by is ideal for far more than walls and floors. With the right mix of skill and knowledge, concrete can be intricately textured, colored and patterned for a multitude of strikingly beautiful uses, from gracious lobbies, pool surrounds and patios to handsome pillars, columns and even countertops.
Like a hand-in-glove, concrete and coatings belong together. Whether the function of the concrete coating is decorative or protective – or a combination of both – coatings and decorative finishes can enhance concrete surfaces in ways that impart style, improve longevity and increase client satisfaction with the project – along the way transforming a dull, colorless expanse into a noteworthy design element.
Dispelling the Myths
Smart contractors, with the help of an ever-growing selection of concrete finishing products, are taking advantage of this increased awareness of concrete’s aesthetic possibilities. As a result, they are expanding their markets by learning the methods and techniques to deliver these exciting new looks. But what exactly do contractors need to know about concrete coatings?
With all of the new products and techniques available to help contractors achieved desired effects, some confusion about coating characteristics and attributes is inevitable.
Myth #1 : All the various products and processes available today to colorize and detail concrete are “coatings.”
From acid-etch stains and color admixtures to concrete etching and overlays, there are numerous ways to enhance the appearance of concrete surfaces. But many of these are not actually concrete “coatings.” Acid, polymer and other chemical stains, for example, are not paints or coatings, but are, rather a coloring process that initiates a chemical reaction with a cementitious surface.
Water-based concrete stains, typically composed of acrylic resins – while technically not coatings – behave more like coating products because they do not react chemically with cementitious materials. Instead, these products penetrate deeply into the concrete surface, providing colorization and protection against harmful elements to both vertical and horizontal surfaces.
Water-based acrylics resist fading and abrasion, and they may be applied using stencil designs to create faux brick and geometric effects. Easier to apply than chemically reactive stains, water-based acrylics clean up with soap and water. Another advantage is compliance with even the strictest air quality regulations due to their very low VOC (volatile organic compound) content.
Myth # 2: Coatings, by their nature, bridge the porous surface of concrete, trapping moisture already present that seeks to escape through the surface and setting the coating up for failure.
Not necessarily. Coatings do bridge porous surfaces, in the process protecting concrete and masonry surfaces from water penetration. But a number of newer concrete coatings are available that are highly permeable from the substrate side. There are new elastomeric coatings, for example, that are as easy to apply as paint, but which allow moisture vapor from within the concrete to escape. This quality virtually eliminates the problems of blistering, peeling and delamination associated with most concrete coating failures.
Elastomeric concrete coatings apply to a thick, elastic film that enhances concrete surfaces by providing uniformity while concealing hairline cracks, patches and other irregularities. At the same time, these coatings improve concrete longevity by providing protection from wind-driven rain, even in coastal or severe-weather environments. They are available in a wide range of colors and also may be tintable.
Textured elastomeric coatings provide these same benefits, while offering the advantage of an imperfection-camouflaging, uniform finish that adds visual interest to otherwise ordinary pre-cast panels or concrete block surfaces. Such coatings are available in different textures, plus a wide variety of factory-tint or store-tint custom colors, so enhancement possibilities are numerous. What’s more, the choice of textures makes it possible to easily match new areas to existing textured surfaces to deliver a clean, consistent look across an exterior expanse.
Myth #3: Concrete must cure for at least 30 days before coating.
While many coating products cannot be applied to “hot” masonry surfaces (NOTE: always carefully read and follow the individual manufacturer’s instructions) some primers and topcoats can be used after just seven days of curing. These systems may provide an ideal solution to schedule conflicts resulting from weather or other job-related delays, or help make possible a fast-track construction schedule.
Look for primers and topcoats that can be used successfully on substrates with surface pH levels from 6-13. These systems are available in white as well as a wide range of pastel and deep-base shades.
Myth #4: Concrete block fillers are unnecessary, heavy and difficult to apply.
What better way to prepare a rough, uneven profile for a beautiful topcoat or decorative finish than using concrete block surfacer? These coatings dramatically enhance a concrete surface by providing a stable, uniform foundation for finishing by filling pores, voids and pinholes – often in just one pass. But unlike the block fillers of old, new, lightweight concrete block surfacers are available today that backroll faster and with less effort, so they save on application time. These products may weigh as much as 30 percent less than traditional block fillers. They are also useful for building a solid barrier between topcoats and the substrate, preventing pH burns even over freshly cured mortar.
Myth # 5: Chalky concrete cannot be coated.
While chalking concrete should not be directly topcoated, it certainly can be prepared for topcoating through the use of concrete conditioner products. These coatings penetrate deeply into masonry substrates to secure chalky surfaces and create a stable base for long lasting finish coats. On new construction, they may be used as a penetrating sealer for surfaces that include 7-day- cured concrete. An added advantage of concrete conditioner use is prevention of topcoat delamination and alkali burn GÀ¡Ãƒ´ even on concrete substrates with pH levels as high as 13. These coatings can serve as an economical alternative to primers and are particularly useful on rehab projects where the existing topcoat has deteriorated over time.
A Word About Surface Preparation
While conditioners can go a long way toward preparing a concrete surface for topcoating, before any coating is applied, some simple steps should be taken to assure a proper bond. Most coating failures occur not because of improper coating application, but because of inadequate surface preparation. For a coating to properly adhere to a concrete surface, the surface must be clean, dry, dull, sound, and free of surface defects such as cracks or spalling. These areas should be repaired using the appropriate patching compounds. The surface to be coated should have a slightly rough profile – approximately equivalent to a piece of 120-grit sandpaper.
Be sure to clean the concrete to remove any grease, oil, dirt, old paint or other contaminants, using one of the methods recommended by the manufacturer of the coatings you will be using for the job. It’s important that the surface is properly prepared so that it is compatible with and receptive to the specific coatings you plan to apply, so be sure to check your tech data pages. Pebble blasting, power washing, acid etching or cleaning with a commercial concrete cleaning agent are among the methods that may be recommended.
Before coating, a concrete surface should be:
- Clean
- Dull
- Dry
- Sound
- Free of surface defects
One-Two Punch: Peel Away and Duration ® Combo is a Residential Restoration Knockout
The challenge: Preparing a two-story farm house, built in 1833, for a fresh paint job by stripping the exterior to bare wood — without damaging the underlying cedar substrate.
Jim Cooper, president of Cooper Painting, explains the challenge he faced at this 169-year-old home near Cleveland:
“We had layer upon layer of paint – latex, oil, white wash and milk paint – on the structure. In all, we figured there were more than 45 layers that had never before been stripped. Much of the paint was lead-based so containment was going to be an issue. And, since the home would be occupied during the restoration, I needed products that were environmentally safe, fume-free, wouldn’t damage the wood and could contain the lead while stripping all those layers of paint.”
Cooper worked with his local Sherwin-Williams representatives to come up with a solution to just this type of situation.
First, he knew that he wanted to use Sherwin-Williams Duration Exterior Latex Coating as his topcoat paint.
“Duration is the best paint I’ve ever used on the exterior of a house – period,” Cooper says. “It flows well and goes on thick. It remains flexible and absolutely resists peeling. We did a home in Lakewood, Ohio, that was having major peeling problems six months to a year after every paint job. We painted it with Duration with our normal surface prep and it hasn’t peeled two years later. Anytime I do an exterior job, I spec Duration.”
For paint removal, Cooper conducted a series of patch tests to determine the best product for the job. The winner was the Peel Away 1 paint removal system, a Dumond Chemicals product available at Sherwin-Williams stores.
“We’ve been using it for six years and are always pleased with the results, “Cooper says. “Peel Away products are more controllable and dependable than other chemical strippers. They’re safer, don’t drip and remove more paint at one time.”
Taking off the paint
Approximately 10,000 square feet of paint had to be removed from the house. Cooper’s crews used a total of 880 gallons of Peel Away 1, most sprayed on to a 1/4- inch thickness using an airless sprayer. Brushes were used to apply it on window sashes and door and window frames.
The next stage was to apply paste and a layer of special Peel Away paper that keeps the paint damp for the required dwell time, preventing lead dust from entering the air.
After a 48-hour dwell time, the old paint and Peel Away products were scraped off with putty knives, and placed in 6-ml plastic bags and then re-bagged into Super Sacks, nylon bags with 6 ml of plastic inside that hold more than 245 gallons worth of waste per sack. These sacks were disposed of according to HUD and EPA rules and regulations.
The first application removed about 75 percent of the stubborn paint layers. A second application – with a 24-hour dwell time – took care of the rest. Cooper then scrubbed the area with low-pressure water and soft bristle brushes. The excess water and paste drained off onto plastic where it was vacuumed into the Super Sacks. A neutralizer supplied with Peel Away was sprayed on to saturate the area and allowed to settle. The area was then scrubbed and pH tested (normal range is between 7. 0 and 7. 5).
Once the substrate was completely neutralized, draw scrapers were used to remove any debris hiding in crevices. Palm sanders outfitted with HEPA vacuums were then used to sand the surfaces smooth.
Finishing touches
Crews then caulked the house with Sherwin-Williams 950A Pro Select Siliconized Acrylic Latex Caulk, primed with XIM Plus and finished with two coats of Duration. More than 200 gallons of Duration were used.
“We’ve been doing one or two restorations like this every year, and it’s a part of our business that is really satisfying,” Cooper says. “We take a lot of pride in restoring a house like this. When we work on a project for six months, we feel like it’s our home. The combination of Duration and Peel Away helps us make it look like it was just built.”