Recent Questions

Q: Is acrylic latex paint a good product for rough-sawn exterior grade plywood siding? Should the plywood siding be treated with a preservative before applying the primer and then topcoat?

A: Quality acrylic latex paint is an excellent choice for painting rough-sawn exterior plywood siding. Preservative treatment of the wood before painting is not necessary if proper construction practices are followed when installing the siding. There should be no contact of the bottom edge of the siding with soil or other surfaces where water can puddle.

Q: I am painting a 5-year old unpainted stucco house with some minor cracking. Is it better to patch the cracks and use acrylic latex paint or use an elastomeric type paint? If I use an elastomeric, is it re-paintable in the future using latex?

A: 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.

Q: What is the best type of paint to use on shutters?

A. Gloss paints are best for paintable shutters and trim because they accentuate architectural details and their finish tends to be hard and smooth.

Q: What is the best kind of paint to use on factory-primed hardboard siding?

A: 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.

Q: I have an old, rusty tin roof to paint. What do you recommend?

A: 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.

Q: A customer wants me to repaint her off-white vinyl siding brown: but other painters have told me to stay away from dark colors on vinyl. Why?

A. 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.

Q: When painting exterior wood, some people recommend caulk to keep moisture out of the wood; others say you should leave gaps to allow the house to breathe. Which is right?

A: 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.

Q: How can I upgrade a coating system from an alkyd to a urethane or epoxy without completely removing the old finish?

A: 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.

Q: I need to paint a new concrete deck around an in-ground swimming pool. What can I use that will not be affected by the water and chemicals?

A: 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.

Q: What kind of paint works best on galvanized surfaces?

A: 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.

Q: My house is 35 years old and has aluminum siding that was painted once by the previous owner. It is now starting to peel. I am planning to paint the soffits, which are wood, and the gutters, which are aluminum. Can you offer advice?

A: The first thing I recommend is a good pressure washing of the entire home. This will help remove contaminants that could affect adhesion of the new paint and should also remove any peeling paint from the aluminum siding. I also recommend you have someone at your local Sherwin-Williams Paint store look at the peeling paint to determine what caused it to peel so you can correct the problem. Assuming that none of the wood soffits or aluminum gutters are peeling, you shouldn't need a primer. Primers are usually necessary only when you are painting a bare substrate. Make sure that any glossy areas are sanded to remove the gloss. Remove any old, cracked caulking and replace with new acrylic latex caulk. The longest lasting paint for exterior use is Duration Exterior Coating. Duration is available in a variety of sheens -- flat, satin and gloss. As for application method, it's up to you. If you have the equipment to spray, it's certainly the quickest way to get the job done. Rolling would be difficult on the aluminum siding. Brushing is acceptable, but very time consuming.

Q: I have a contract to paint the exterior of an apartment complex with rough, vertical grooved plywood siding. Most of the previous solid color stain is worn away. What should I use for the longest lasting job?

A: Alkyd paints are "usually" not recommended for application direct to aluminum because of possible saponification (a reaction between the fatty acids in the alkyd and the aluminum salts when moisture is present). Since most aerosol spray enamels are alkyd based, you have the potential for problems when you apply them to aluminum. An epoxy ester or acrylic aerosol spray would be a better choice for painting small pieces of clean aluminum.

Q: What is better on exterior rough sawn plywood siding: stain or paint; latex or oil?

A: Since plywood is made up of many layers of wood that expand and contract, coatings applied to it are prone to cracking and checking. Stain is an ideal coating for rough sawn siding since it is designed to provide a natural, rustic appearance. Use either an alkyd semi-transparent or an alkyd or latex solid color stain. If a less-natural finish is desired, an acrylic latex primer followed by an acrylic latex topcoat can also be used. These types of paint will protect the wood from the elements and be resistant to cracking and checking. Avoid using an alkyd primer and topcoat system, as it could lead to early paint failure and possible damage to the siding from moisture and sunlight.

Q: What type of caulk should I use to fill cracks in my stained cedar siding before re-staining?

A: If you're using a semi-transparent stain, find a stain and an acrylic latex caulk that match, re-stain then caulk. Semi-transparent stain doesn't do a good job over caulk. If you're using a solid color stain, caulk with the same acrylic latex caulk, then stain. A clear caulk will also work.

Q: What colors are least likely to fade when used outside?

A: First of all, realize that all exterior paints will eventually lose some of their color integrity. However, the rate of color loss will vary from color to color and paint to paint. Organic colors (blues and greens) will tend to fade more quickly than inorganic colors (brown and yellow iron oxides). Also, high-quality acrylic latex house paints will retain their color better than solvent-based paints. In general, higher quality exterior latex house paints will resist fading better than lower-cost latex house paints. Remember, interior paints are not designed to hold up in exterior applications. Fade resistance is one of the most noticeable benefits of exterior formulated paints.

Q: Many homeowners want their doors, windows and shutters covered with a semi-gloss latex paint because they believe it will wear better than a flat latex. Is semi-gloss more resistant to abrasion and wear than a flat latex?

A: Semi-gloss latex paints contain more binder than flat paints, so they do tend to be more durable. In general, the greater the volume of latex binder in a paint, the better its toughness, adhesion and color retention. Semi-gloss paints are also more stain resistant than flat paints, so they'll pick up less dirt and tend to wear better than flat latex paints.

Q: Why is it so common that the deep colors (hunter greens, deep burgundies) never touch up, even when using the same paint that was originally used just a few days or weeks later?

A: Deep colors are naturally loaded with pigments that need to stay dispersed in the paint during application. If the paint is not stirred frequently, you could be applying different concentrations of colored pigments at different times during application. Then when you go back to touch up with a freshly stirred bucket of paint, you could be putting more or less pigment onto the wall, causing it to look different. When touching up painted surfaces, it's a good idea to use the original can of paint and reduce it 15 to 25 percent. This will prevent film buildup, which can also cause a difference in appearance. You should apply the touch-up paint with the same type of applicator (brush, roller or spray) you used to apply the original paint. This will prevent texture differences, which make the touch-up areas more visible.

Q: Will acrylic latex house paint stand up to a harsh seashore environment where there is high humidity, wind-driven rain and salt? Or must an oil-based paint be used?

A: Acrylic latex paints have demonstrated outstanding durability in the most rugged environments including direct sunshine, moisture from rain and snow, and at the seashore. Due to the superior adhesion of acrylic latex paints, they don't tend to blister, crack or flake when exposed to rain or high humidity. Remember that the most important part of repainting is surface preparation. While priming is usually not necessary for some repaint surfaces when using an acrylic latex paint, it's a good idea to prime any bare wood. For the best performance in the seashore environment you describe, it's advisable to carefully wash away any salt deposits found on the surface to be painted along with any "chalk."

Q: Is it advisable to apply an exterior alkyd over an existing latex?

A: No, it isn't. The alkyd layer will get hard and brittle as it ages, but the latex underneath will remain flexible. As time passes, the latex layer will flex and move with the expansion and contraction of the substrate more than the alkyd topcoat will. This will compromise the adhesion of the alkyd to the underlying latex and cause the alkyd topcoat to peel.

Q: Does bleach really kill mildew on a wood deck?

A: Chlorine bleach (sodium hypochlorite), when mixed in proper proportions, removes mildew stains and kills the living mildew spore growth on the wood surface. However, it will not kill mildew deep in the wood. Mildew needs nutrients to live. A bare, unprotected wood surface provides a lot of food for the spores to thrive on. The same is true for deck stains that contain linseed oil. Once the deck is bleached and pressure washed, make sure the wood is thoroughly dry before staining. Use mildew-resistant clear finishes, semitransparent and solid color stains, like those from the DeckScapes line designed specifically for decks.

Q: What's the best way to paint exterior brick? What techniques will give it a unique finish or texture?

A: First, let new brick weather a year before painting. This allows any ores in the brick a chance to leach out. It's a good idea to pressure wash the brick before painting to get rid of any powdery mortar or deposits on the brick. Allow the brick to dry several days before painting. If the brick has a glaze on it, and it doesn't absorb water, you'll need to abrade the brick in some way to open it up so the primer will absorb into it. Make sure the brick is clean before priming. We suggest priming with Loxon Exterior Masonry Primer or Loxon Masonry Conditioner. After priming, topcoat with two coats of a 100% acrylic paint, such as Super Paint. You can add some texture by using an exterior sand finish texture paint or an exterior stucco finish paint as your finish coat.

Q: I have a house with masonite siding that hasn't been painted in several years. In places the paint is in really bad shape. What is the best way to remove the old paint? Do you recommend a quick-drying primer/sealer for priming damaged masonite siding?

A: The best way to remove the old paint is by scraping and sanding to bare wood. Be careful not to be too aggressive or you'll damage the siding. If the siding has deteriorated, or is "swelling" due to water absorption, it should be replaced. I recommend an exterior grade alkyd primer followed by two coats of acrylic latex house paint. The alkyd primer is best because it seals better on the lower edge of the siding, which helps prevent edge swell, a common problem on hardboard siding.

Q: Do acrylic latex primers and topcoats "breathe" to allow moisture vapor to pass through? Does this breathability diminish when a second topcoating and subsequent repainting is done?

A: Studies have shown 50 gallons of water is vaporized into the air of an average home each day from cooking, bathing, laundry and people. Much of this moisture passes through the walls. If the exterior coating traps moisture, blistering and peeling will occur. Moisture vapor is more likely to pass through acrylic latex paint films than through solvent alkyd types. It's true that application of additional coatings will reduce moisture vapor transmission, simply on the basis of increased film thickness. However, even with several coats applied, the latex film will be adequately permeable to water vapor and better than alkyd paint films of comparable thickness.

Q: Why should I use a 100% acrylic house paint instead of a less expensive vinyl acrylic?

A: The benefits of using a 100% acrylic versus a vinyl acrylic or alkyd modified exterior latex are improved adhesion and better gloss retention, and fade- and mildew-resistance. As a result of this improved durability, you don't need to repaint as frequently. You may pay a few dollars more per gallon for a 100% acrylic paint, but when you factor in the extra years of service your customers get from the paint job, it actually costs them less and saves you time on expensive call-backs.

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