One key to how long an exterior finish lasts is how well the surface is prepared. But equally important is the choice of the paint or stain itself. Using high-quality materials, matching them to your house and climate, and conducting regular maintenance will extend the time between recoatings.
Expect to pay $35 to $45 per gallon for conventional premium paint or stain. “Green,” or zero-VOC, products run $45 to $55 per gallon. A gallon covers 350 to 400 square feet, so figure on about 8 gallons to cover an average two-story, 30-by-40-foot house. Most paint jobs require a primer and two topcoats.
Acrylic latex paints
Acrylic latex is the favored choice, both of pros and do-it-yourselfers. These water-based paints come in an endless range of colors and three popular finishes. Flat paint, commonly used indoors, offers the least protection against the elements. Satin, with its slightly higher sheen, is a good choice for wood siding. Semi-gloss or gloss offers the most protection and works well on high-use areas like window and door trim.
Pros: Latex paints are easy to work with and clean up with water. The paint film remains flexible even after drying, so it breathes and moves slightly to accommodate changes in temperature, or even house settling, without cracking. In addition to wood, latex can also cover siding made of vinyl, aluminum, fiber cement, stucco, brick, and metal.
Cons: Unless you’re using “green” products, expect to smell paint fumes from the moment you open the can until the paint dries completely. These odors, produced by volatile organic compounds, are toxic in high quantities and contribute to air pollution.
In general, latex paint doesn’t bond well to previous coats of oil paint unless you prepare the surface very well. That means stripping nearly all the old paint off the wood first, a time-consuming and expensive job. It’s often smarter to stick with oil if you’ve got oil, and latex if you’ve got latex.
Costs: $35 to $45 a gallon for premium latex paint; $45 to $55 a gallon for premium low- or zero-VOC paints.
Oil paint, long prized for its durability, used to be the gold standard for exteriors and some high-traffic house trim such as handrails, doors, and floors. But these days it plays second fiddle to latex.
Pros: Oil paints dry hard and get harder with time. That makes them perfect for high-traffic uses: porch floors, steps, metal handrails, even your front door.
Cons: Over time, oil paint can become brittle and crack, producing an “alligator” look. (Some people actually like the effect.) Oil paint can never be applied on top of old latex paint; the two won’t bond properly.
Toxic solvents are required to clean brushes and other equipment that come in contact with oil paint. The average can of oil paint has more VOCs than a can of conventional latex paint. Low-VOC oil paint is available, but even these products contain more VOCs than low-VOC latex paint.
Costs: $35 to $45 a gallon for premium oil-based paint; $45 to $55 a gallon for premium low-VOC paints.
Stain is the choice when you want to let some of the natural features of the wood shine through but still shield your investment from the elements. Cedar, redwood, and other beautiful varieties cry out for stain. As a rule, stain isn’t as protective as paint; sunlight and weather can still penetrate the stain, causing the wood to age and discolor.
Like paints, stains come in latex and oil-based versions. You don’t want to cover an oil with a latex stain, or vice versa, unless the old coat of stain has aged and weathered to the point where the new coat can adhere.
Stains come in three finishes:
Clear stains are extremely translucent. You’ll see more of the wood, but you’ll need to reapply as often as every two to three years. Clear stains can still vary greatly in appearance, so you will want to experiment on a scrap piece of shingle to choose your favorite product. Over time, the wood under clear stain will continue to discolor, forcing you to eventually move to the next category.
Semi-transparent stains are bulkier and offer more protection than clear stains, because they contain a hint of pigment. Color choices are not nearly as numerous as those for latex paint, but there’s still a broad range of options. Reapply in five to seven years.
Opaque stains behave more like paint; they offer maximum protection and hide much of the wood’s look. But they still allow the texture to show through. These come in many colors, but choose carefully–if you want to change colors next time around, you’ll need to sand the surface completely. Opaques last 10 years or more.
Pros: Stains don’t require extensive surface prep the way paint does. Just wash, dry, scrape any raised or cracked stain, and re-stain with a brush. You don’t need a primer and may be able to squeak by with one coat.
Cons: Depending on type of stain, requires frequent reapplication.
Costs: $35 to $45 a gallon.
It’s worth springing for the good stuff
To make sure you’re purchasing a quality product, buy at a reputable paint store and ask sales clerks for recommendations. When buying latex paints, choose ones that are 100% acrylic polymers or resins, labeled on the front or in the ingredients list. Low-quality paint feels thin, runs down surfaces, and spatters off rollers. High-quality paint feels thicker, levels well when applied, and hides the old paint layer or primer in one to two coats, tops.
When it comes to stain, brand name and reputation are the best indicators of quality. Ask for recommendations, accept the higher price, and don’t try to cut corners.