Pick the right paint
Stumped by the wide variety of paints on the store shelf? You’re not alone. Whether you’re out to paint your whole house or simply touch up the back fence, selecting the best paint or stain for the job can be confusing. No one type of paint or stain is best for all surfaces, especially on the exterior where it takes a beating from the weather.
In the following pages, we’ll list the common exterior painting tasks and then recommend the best finish for the job. But keep in mind that certain materials or weather conditions may warrant different choices, especially when painting over old coatings. Talk to the staff at a local full-service paint store for additional advice.
Primers fill the pores in wood and form a good adhesion base for topcoats. They’re lightly pigmented to help the topcoats cover better.
Oil-based (alkyd) primers are the old favorite, but high-quality acrylic latex primers are now available and a popular choice of many pros. Both work well. In either case, be sure to buy a quality product and spread it to the proper thickness. Better primers are more expensive. Read the directions on the label to determine the ideal application thickness. A common mistake is applying it too thinly, like a wash, rather than as a regular coat.
When priming cedar or redwood, use an alkyd primer or a stain-blocking acrylic latex primer. Cedar and redwood have water-soluble tannins in their heartwood that, when moist, will leach out and “bleed” through the topcoats, leaving dark, ugly stains. Alkyds and stainblocking acrylics bind the tannins and hold them in the primer. Buy a brand from a dealer who will guarantee the product’s performance.
Knots can also bleed through the topcoats. To prevent this problem, double-prime them. First prime just the knots with the alkyd or stain-blocking acrylic primer or pigmented shellac (such as BIN). Let the primer dry, and then prime the entire wood surface.
TIP: Choose your paint first, then read the label and buy the primer recommended by the manufacturer. Some paints perform best when used with the same brand of primer.
In this category, we’re including any smooth or rough surface wood that’s fully exposed to the weather, like exterior railings, gazebos and arbors. The trade-offs between paints and stains are the same for fences as for decks (see “Decks,” below). Film-forming finishes like paint and solid stains last longer and have stronger colors, but will inevitably peel and require more effort to renew. Semi-transparent oil stains won’t last as long. However, if you apply them properly, they don’t form a film, so they won’t peel and they’re easier to recoat when they weather and fade.
Acrylic latex resists the corrosive effects of sunlight better than oil-based paint. It lasts longer too. The labels on latex paints can be confusing. Top grades will say 100 percent acrylic latex to distinguish them from other types like acrylic latex or vinyl acrylic latex, which usually cost less and don’t perform as well.
Siding paint has a flat, non-reflective finish, so your house won’t shine like a brand new automobile. In addition, flat paint hides chips, dents and other siding imperfections; higher-sheen paints highlight them. “Eggshell” paint has also become popular. It has a flat appearance too, but also a smoother, easy-to-clean surface.
The few extra dollars spent for high-quality paint will pay off. High-quality paints have a higher volume of better pigments for more thorough coverage and better resins for superior adhesion. They also contain additives that make the paint brush out smoother without dripping or sagging. All these factors save time and money in the long run.
Latex paints are more temperature sensitive than oil-based paints. Unless the label says otherwise, avoid using latex paints in temperatures below 50 degrees F or in direct sunlight, which can cause them to dry too fast.
Painting trim involves a lot of time-consuming prep work and brush work, so choose a premium paint for the longest-lasting protection—gloss or semigloss 100 percent acrylic latex. They’re more durable than flat latex because they have a higher resin content. The additional resin also delivers that glossy sheen, but because the trim covers a relatively small area, the shine isn’t prominent.
Some painters prefer oil-based trim paints because they have slightly higher initial gloss and brush out smoother. However, they’ll dull and fade within a few years if the sun hits them. Glossy paints highlight surface flaws, so if your trim is worn, stick to the semigloss or even a satin sheen in highly visible areas.
TIP: If the old coat is oil-based, you can paint latex over it. However, you must sand the old surface to ensure good adhesion.
Porch floors and stair treads
Exterior wood floors that are exposed to rain and sun always take a beating. Foot traffic wears away the finish. And the simple fact that paint slows the drying process once the wood gets wet will compound the problem by encouraging rot. No protective coating will be low-maintenance.
A specially formulated exterior floor paint usually works best. Floor paints usually contain harder resins to withstand abrasion. (Some manufacturers also call this paint an enamel, which simply means that it has a high resin content for maximum adhesion.) Still, expect to scrape and renew peeling areas every few years. TIP: One way to extend paint life is to prime all sides of the flooring before laying it.
These paints will be glossy, and sometimes slippery when wet. Gritty additives can provide good traction in the short run but may soon wear off in high-traffic areas. We’re applying a non-skid surface coat that contains grit. Look for anti-slip paint at full-service paint stores.
New hardboard or cementboard
Hardboard has a factory-applied finish, and each brand has specific painting instructions. Painting methods vary, so read those instructions. Usually a primer and two coats of 100 percent acrylic latex will do the job.
TIP: Prime well any cut ends and nailheads driven through the surface. Hardboard can deteriorate where the raw fiber is exposed.
Semi-transparent oil stains work best. They soak into the rough fiber and protect the wood from weathering, but they don’t form a surface film and therefore won’t peel. They contain enough pigment to color the wood and partially shield it from the sun, but not so much as to hide the texture and grain. Weathering, especially sunlight, causes stains to break down, erode and fade. They typically last only three to six years on the sunny side of the house. But renewal requires only a thorough cleaning and recoating.
Solid stains contain more pigment and deliver stronger colors. They’ll often last a year or two longer than semi-transparent oil stains. However, they tend to form a thin film and often peel, requiring more time-consuming prep work before you can apply a new coat. This is especially true of solid acrylic latex stains.
Semi-transparent stains that contain a combination of oil-based resins in a water solution also perform well.
Paint usually doesn’t adhere well to rough wood, and it’s tough to scrape and sand off loose paint once peeling begins. So avoid using film-forming finishes like paint and varnish.
To slow rot and other deterioration and keep the deck in good condition with the least effort, simply apply a water repellent preservative every year or two. If the deck wood is damp much of the year, clean it and kill the mildew every few years with a deck cleaner (sold at home centers).
For a more attractive appearance, apply a semi-transparent oil stain. Use lighter stains for deck boards; heavier pigmented types show wear faster and are more difficult to renew. You’ll have to strip the deck and renew the stain every two to four years.
Clear exterior finishes, intended to preserve the natural color of the wood, will last only a year or two before they peel and the wood begins to turn gray.
Concrete, concrete block, stucco and brick walls
Sound and clean concrete, stucco and masonry accept paint well. But beware. Moisture that gets under the surface will eventually cause the paint to peel, especially on horizontal surfaces. And you’ll have a tough job scraping and prepping the rough surfaces.
For best results on vertical exterior surfaces, select 100 percent acrylics. They breathe, meaning water vapor can move through them, which allows any low level of moisture that gets inside to evaporate without lifting the paint. Avoid oil-based paint because surfaces that contain cement typically are strongly alkaline and can soon shed the paint.
If the wall has a lot of small cracks, a better option is often an acrylic elastomeric paint, which is a thicker, more flexible version of regular acrylic paint. But always discuss options and warranties with an experienced paint dealer before trying an elastomeric. It costs about 15 percent more per gallon but has a lower coverage rate. In the end, it’ll cost two to three times as much as standard acrylic paint.
Concrete stain is a better choice for sprucing up horizontal surfaces. It wears more slowly than paint and is easier to renew.
Galvanized steel and aluminum
Let new galvanized steel and aluminum weather for six months, or wash the bare surfaces with an all-purpose household cleaner or TSP to remove oily residues. Then apply 100 percent acrylic latex. You won’t need a primer. However, if galvanized steel has rust spots, sand off the rust and apply a rust-inhibiting metal primer to those spots first.