Selecting the paint you’ll use to protect and decorate your home’s exterior shouldn’t be a rushed or impulsive decision. It’s important to keep in mind that paint’s main function is to prevent damage to the house. Its attractive color and sheen are significant but secondary. Paint companies must create products that are both pleasing to the eye and likely to last.
Why Are There So Many Kinds of Paint?
Though preparing your home’s outside surfaces for painting is crucial, picking the right paint is just as important. If you don’t know the ins and outs of exterior finishes, you won’t be able to get the best results, aesthetically or in terms of protection.
How Paint Works
When paint dries, it produces a water-resistant layer that shields your house from most weather damage. Most of paint’s mass is comprised of colorants, binding agents, and solvents. Most paint also includes ingredients that make it protective against ultraviolet rays and mold, less difficult to apply, and/or less likely to splatter. Colorants consist of tiny particles joined by the binding agent, which also attaches them to walls and other features.
A substance with binding properties — such as alkyd, vinyl, acrylic, or latex — is typically included in the production of paint. All of these except alkyd consist primarily of water and result in water-based paint. In contrast, alkyd’s solvent is paint thinner, also known as mineral spirits. Before alkyd paint existed, non-water-based paint relied on plant oils (e.g., linseed) as solvents. Consequently, alkyd is classified as an oil-based paint.
Dry paint’s protective layer consists of binding substances and additional ingredients that remain when the colorants evaporate. The more binders and additives a paint has, the more effectively it will keep the house safe from the elements. Inexpensive paint may seem like a bargain at the store, but it costs more in the long run. Once it’s on your house, you can expect it to deteriorate more quickly and offer less protection.
From a scientific perspective, we’ve only scratched the surface (so to speak) of how paint works. Nonetheless, the difference between water- and oil-based paint is an important basic principle to understand.
Types of Paint for the Home
Just as there’s a rule of thumb about mixing beer and liquor, there’s one about how oil- and water-based paint interact. You can cover old latex paint with new alkyd paint, but the reverse is highly inadvisable. If you want to paint with latex on a wall finished with alkyd, you have to use a primer in between.
Neither water- nor oil-based paint is objectively better; which is right for your project depends on its nature.
Latex paint currently dominates the industry. Having water as a base allows it to dry rapidly and produce virtually no scent. In addition, latex paint is easy to wash off and has little impact on the environment.
Nonetheless, latex paint usually includes some quantity of volatile organic compounds (VOCs). Some individuals are sensitive or even allergic to these chemicals. Fortunately, paint with little or almost no VOCs is available.
Water, the aspect of latex paint that accounts for its advantages, also causes a few of its shortcomings. It becomes difficult to use at temperatures below 50 degrees Fahrenheit, and it’s easier to see brush strokes in the final result. Manufacturers have engineered a type of latex paint that works at 35 degrees or above. However, it still cannot tolerate freezing temperatures, while it’s being applied and directly afterwards. If it does freeze during that window, its protective abilities become significantly compromised.
The most important thing to know about latex paint is what sort of binder it contains. A high percentage of acrylic resins indicates a solid product. You may find such paints labeled as “acrylic latex.” If you can swing it, paint that’s 100 percent acrylic is the way to go. It tends not to splatter or chip, it brushes well, you can scrub it (once it’s dry) without fear of harming the finish, and it holds its color and gloss very well.
The main alternative to latex, alkyd paint is what many contractors prefer. It lasts, stains come out of it, and it doesn’t show brush strokes as much as water-based paint. When applied skillfully with a high-volume, low-pressure spraying device, it looks about as good as house paint can.
Alkyd paint does have a few downsides, however. Thanks to a significant concentration of VOCs, alkyd’s aroma is powerful, and it isn’t nearly as quick drying as water-based paint. While painting with it, you should open any windows and doors you can. Even so, your house will smell like chemicals for a time.
There are benefits to paint that doesn’t dry quickly. Perhaps the most obvious is that it continues moving after being applied, which gives the surface a more even look. If used overzealously, however, a coat of slower-drying paint can droop a bit. A finish with a saggy appearance requires another layer of paint, which can make the job drag on.
Shortcomings aside, well-made alkyd paint is very effective under the right circumstances. Indoor trim, cabinets, and doors are particularly well suited to it.
Alkyd and latex paints dominate the market, but they’re not the only types worth understanding. Elastomeric finishes live up to their name; their thickness and stretching power help cover cracks in masonry. Elastomeric paint can also be useful on certain kinds of wood.
While you’re most likely to encounter direct-to-metal paints in industrial contexts, some varieties are sold in regular paint stores. As you might imagine, these finishes work well with metal siding, especially steel. They’re nearly always used outdoors.
If you’re looking for a finish characterized by uncommon strength, epoxy paint might be for you. Exclusively an indoor product, it stands up to chemicals and is often found in garages, whose floors tend to experience a great deal of wear and tear.
A wood porch floor is a fine place to use urethane enamel. It’s not easy to scratch, and it offers the sort of bright sheen associated with oil paint.
Obeying the adage that everything old is new again, paints made in pre-industrial ways are making a comeback. These finishes eschew artificial ingredients, instead favoring colorants and binding agents derived from plants and other sources in nature. Some paints of this type manage to be both aesthetically pleasing and resistant to wear.
Picking Outdoor Paints
If only you could choose a kind of exterior paint once and be done with it. For better or worse, it’s not that simple. The finish you need for a given project depends in part on the surfaces it involves. Siding and wood both swell and shrink over the course of a year, due to temperature changes and weather conditions. You’ll want to cover them with a paint that can do the same. A pure acrylic paint, for example, should be flexible enough to avoid cracking.
Wherever you live, there are surely climatic quirks that will impact your outside paint jobs. Cold, heat, dampness, and dryness all have different effects on exterior finishes. Your area’s weather profile will help you decide which type of paint to buy. One additional factor related to climate is ultraviolet light. Sunny places are a challenge for alkyd paint, since UV causes it to break down more quickly than it normally would.
In general, a store that specializes in paint offers better advice than a big-box store. Consider this when deciding where to purchase paint. Paint-store staff can be highly informative when it comes to the finer points of painting exteriors in your particular neck of the woods.
Like nearly every aspect of house painting, there’s an element of trial and error in figuring out which paints work best with which surfaces in which season. The more outdoor painting you do, the wiser you’ll get on the subject.
Selecting Paint for Indoor Projects
Deciding on paint for inside your home is not nearly as complicated as picking outdoor finishes. For one thing, the “climate” of your interior space should be fairly consistent, and it’s usually simpler to get the lay of the land and determine what’s needed. There are also fewer paints to choose from.
Things to Keep in Mind
Standing Up to Scratching – No two rooms get the same amount of use. In terms of the impacts they have to absorb, kids’ rooms differ from doors, hallway floors differ from trim, and so on. Alkyd finishes are hard to scratch, so they work well on floors, doors, and trim. Acrylic paints, on the other hand, are elastic, go on easily, and don’t smell much.
Dampness – In bathrooms, pools, and steam rooms, paint can be highly affected by moisture. Whether a finish is oil based or acrylic, it should stand up to water pretty well. That said, acrylics tend to outperform alkyds in humid areas. The wetter a space is, the glossier your finish should be.
Glossiness – Glossier paints last longer, stretch more, and don’t scratch as easily as their matte counterparts. They’re also better at standing up to scrubbing and water. Your paint’s level of glossiness should therefore depend on what kinds of surface(s) you’re working with, and how you want them to look.
Hue – If you need to apply several layers of paint to a surface, an acrylic finish might be best, since these produce thick coats and dry quickly. How colorful you want your home to be should also factor into your paint shopping.
Parts of a house that get a lot of “abuse,” such as doors and trim, are good candidates for alkyd paint. That’s because oil-based finishes are tougher in the face of repeated, long-term impact (of sneakers against baseboard trim, for example). Ceilings and vertical surfaces, which suffer less, may do well with an acrylic finish.
Provided that you have plenty of time to paint, and appearance is your priority, the rich, smooth look of alkyd paint might be apt. If time is of the essence, on the other hand, acrylic paint’s ability to dry quickly could outweigh the virtues of an oil-based finish.
The Importance of Well-Made Paint
In addition to decorating, paint can help protect a home from the elements. For that reason, it’s not a good idea to use paint of low, or even mediocre, caliber. Even excellent finish, in order to be effective, must be applied with skill after the appropriate prep work (e.g., priming and caulking) has been completed.
Well-made equipment and paint, paired with skillful work, can create very durable work. Saving money on paint and tools in the short run can cost more later. Further coats may be needed, and problems related to the materials’ low quality may require fixing.
If paint that costs $10 more per gallon lasts six years longer, is it a worthwhile investment? For most homeowners, the answer is yes. Painting one’s house is a big project, and having to do it only once a decade is something many people are willing to spend a little extra money on. When you factor is the cost of the work, whether you’re doing it yourself or hiring someone, spending less time and money in the long term sounds quite appealing.
Cost Estimate for an Outdoor Painting Project
If your house is on the smaller side, and you use paint that costs $15 per gallon, you may spend $250 on paint and equipment and $1,500 on the work itself, for a total of $1,750. If you have to repeat the entire process in four years, your total expenditure in less than a decade is $3,500, provided the prices of paint, tools, and labor haven’t increased (not a sure thing, by any means). In contrast, higher-quality paint that brings your total to $1,850 could last eight years. During that span of time, the cost differential between using less expensive paint and better paint is a whopping $1,650.
If you’re using pricier paint, you may insist on more careful preparation and work, which can add to your labor cost. Still, you’re bound to save a significant amount of money by going with high-caliber paint — and skilled, experienced workers — from the start.