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Paint rarely fails over broad surfaces. It usually starts small—at a crack in the caulk or a separation in a joint—but these small problems grow and soon become major if you neglect them. Before you know it, you’re spending your whole summer scraping and painting your house. Don’t let little problems ruin an entire paint job. You’ll save a ton of time and money in the long run by giving your exterior paint an annual checkup and spending a day or two each year to keep it in tip-top shape. Follow these seven guidelines to extend the life of your paint and keep it looking like new.
1—Replace cracked and peeling caulk
Moisture is the enemy when it comes to your paint job, and joints between siding and trim and around doors and windows are the most vulnerable points of attack. A key weapon in the war against moisture is caulk. Inspect all caulked joints, and clean out any caulk that has cracked or pulled loose (Photo 1). Even a fine crack will absorb water and eventually cause nearby paint to peel. Then spot-prime all bare wood (Photo 2), working the primer back into the gap. The primer improves caulk adhesion as well as seals the wood from moisture. Now apply an acrylic or siliconized acrylic caulk (Photo 3). Avoid using 100 percent silicone caulks in areas to be painted—paint won’t stick to silicone. Make sure the caulk spans the gap and adheres to both sides. Immediately after applying caulk, wet your finger and run it lightly along the caulking bead. Your caulk job will look neater and it’ll adhere better. Allow the fresh caulk to set overnight, then paint.
1. Scrape or cut away all loose and cracked caulk with a putty knife. Work both sides of the crack until you reach a solid surface.
2. Sand the area with a medium-grit paper or sanding sponge and prime the bare wood. Work the primer back into the crack to seal the wood.
3. Lay on a new bead of caulk to span the crack and smooth it out with your finger. Touch up with two topcoats of paint.
2—Fix loose and peeling paint before it spreads
Peeling, blistering or flaking paint is usually the result of moisture getting under the paint. So once you spot the peeling, get after it quickly before it spreads.
The best tools to remove loose and peeling paint are a heavy-duty paint scraper for broad, flat areas and a flexible 2-in. putty knife for tighter areas. Buy a paint scraper that takes replaceable carbide blades. Carbide blades (about $7 each), stay sharp and remove paint faster than regular steel blades.
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Use a lighter touch on composite (hardboard) siding and trim to avoid gouging it.
Scrape off as much of the loose paint as possible (Photo 1), then sand smooth by hand with a sanding block or sanding sponge (Photo 2). Be sure to sand all bare wood. After sanding, the bare wood should look bright and fresh rather than weathered. Dust off the surface and spot-prime, then paint (Photo 3). To keep the problem from recurring, see “Moisture Causes Paint to Peel”.
Moisture causes paint to peel
For best results long term, find the source of the moisture and stop it before you repaint. Most often the problem occurs at joints in the siding or trim, where water can seep into a crack. Joints around windowsills and where wood meets concrete are particularly vulnerable, as are areas that receive a lot of splashing from rain. Maintaining sound caulk at joints and keeping gutters and downspouts clear will reduce many problems.
In some cases, moisture that escapes from your home can cause as much damage as outside elements. When paint peels in sheets down to bare wood or bubbles and blisters (photo above) on an exterior bathroom or kitchen wall, the cause is usually interior moisture moving outward through the wall. Better ventilation in the room, or applying a moisture barrier primer or paint to the interior wall will often solve this problem.
Another cause of paint failure is alligatoring (see above), which is multiple layers of paint that have hardened and cracked. Eventually you’ll have to remove all the alligatored paint. Note: The older layers often contain lead.
PAINT BLISTER
ALLIGATORING
Caution:
If your home was built before 1979, check the paint for lead. Call your public health department for instructions on how to do it. Don’t use the scraping or sanding techniques we show here on lead paint because doing so will release lead dust, the primary cause of lead poisoning. For more information on lead paint, visit www.hud.gov/offices/ lead or call (800) 424-LEAD.
1. Scrape the area thoroughly with a carbide scraper. Remove all loose paint. Use a flexible putty knife to pop off loose edges.
2. Sand the scraped wood to remove all weathering and to feather painted into unpainted areas. Use a medium sanding sponge or 100-grit sandpaper.
3 Prime all sanded areas and repaint. Use two top-coats to ensure longevity.
3—Give horizontal surfaces special attention
Windowsills, handrails and other horizontal surfaces are difficult (at best) to keep looking fresh and decently painted. Rain, slush and snow sit on top of them (sometimes all season long), taking advantage of every crack and chip in the paint to soak the wood beneath. To repair, scrape away all loose paint (Photo 1), and smooth the edges of the remaining paint as much as possible by sanding with a medium-grit paper or sanding block. Dust off the surface and brush an anti-peeling, binding agent such as Zinsser Peel Stop over the entire board (Photo 2). Peel Stop is a clear, thin coating that slides into every crack and crevice, forming a continuous, highly flexible, gluelike seal. Ask for it or a similar product at a paint store. After the binding agent has dried (but within 24 hours), prime with a quality primer and finish with two topcoats. Keep in mind that binding agents are pretty good at gluing down old paint edges, sealing cracks and checks, and sticking to chalky surfaces, but they’re no substitute for thorough surface preparation. And even with the best prep work, you’ll probably have to touch up horizontal surfaces every few years.
Editor’s note: Keep leftover paint from hardening
I get many calls for touch-up work. But when the homeowner gives me the paint from the last job, it has usually skinned over and hardened. To avoid this problem, keep leftover primers and paints in near-full cans. Paint stores, and many home centers, sell empty quart paint cans and covers for about $1. Pour off your partial gallon leftovers into the quart cans to keep them from drying out. Then brush a sample of the color on the side of the can so you can identify it easily. Even better, include the paint color code so you can buy an exact match years later.
Good painting!—Mark
1. Scrape and sand peeling horizontal surfaces thoroughly. Remove all loose paint and make sure the surface is completely dry before priming.
2. Apply a special binding primer to the bare wood, making sure to saturate cracks and the edges of the old paint. When it’s dry, apply two topcoats.
4—Keep your gutters clean and free flowing
When leaves, pine needles and other debris obstruct gutters and downspouts, water overflows onto the siding and trim. That water usually finds a crack in the paint, quickly soaks the wood underneath and begins lifting paint. A year or two of periodic soaking can cause more damage than a decade’s worth of normal weathering (see photo). If the moisture is left unchecked, rot will begin as well. Rot is a major headache and difficult to fix. The best strategy is to cut out and replace all spongy or rotted wood, ideally the entire damaged board. Or if the rotted area is small, you can often dig out all the spongy, loose wood fiber and refill the area with a special two-part filler. (Minwax High Performance Wood Filler, $6 to $10, is one brand found at many home centers and full-service hardware stores.) Only then can you repaint.
Overflowing or leaky gutters will quickly cause extensive paint damage and encourage rot. Clean gutters in spring and fall.
5—Rinse off your house once a year
A year’s worth of grit and grime can sap the life from any painted surface. When combined with wind and rain, the dirt grinds against the painted surface, dulls it and reduces its life. You need nothing special for an annual washing—just a strong stream from your garden hose (Photo 1). Pay special attention to those areas where dirt and grime gather: under roof overhangs, along eaves, above windows and doors, beneath windowsills, behind shutters, and along the bottom few rows of siding. Take care not to drive water into cracks or open vents, and keep the stream of water away from electrical lines.
Rinse your house annually with a strong stream from the garden hose, paying special attention to those areas where dirt gathers.
6—Seal nailhead stains before they get worse
If left alone, rust stains not only look bad but also allow moisture in and cause the paint to crack and peel. Sand the stain or rust from the area (Photo 1) and drive the nailhead below the surface about 1/16 in. (Photo 2). Prime with a good stain-blocking primer (BIN or KILZ are two examples). When dry, fill with a dab of caulk (Photo 3), smooth with your finger and allow to set before repainting. Caulk shrinks a bit as it dries, leaving a slight dimple. For a perfectly smooth finish, apply an exterior filler with a putty knife. Sand the filler lightly when dry and prime a second time before painting.
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Treat cedar and redwood staining much the same as nailhead staining. Sand and prime with a stain-blocking primer. Minimize that just-touched-up look by repainting the entire board.
1. Sand rust and stains away with a medium-grit sandpaper or sanding sponge.
Click Image to enlarge.
2. Set the nail about 1/16 in. below the surface and prime with a quick-drying, stain-blocking primer.
3. Fill the hole with acrylic latex caulk and smooth it with your finger. After the caulk skins over, repaint.
7—Control mildew
Mildew is a dark, blotchy-looking fungus that’ll grow on any moist surface of your home. You’ll generally find it in shady areas like under the eaves, on porch ceilings, on north walls and behind shrubbery—any area that stays moist. It may look like dirt or dust, but here’s a test to tell if it’s mildew: Dab a bit of regular household bleach on the suspect area (Photo 1). Rinse after a minute. If the discoloration disappears, it’s probably mildew, because the bleach has killed it.
A simple washing is all that’s required to remove most mildew. Scrub the affected areas with a stiff brush, hot water and an all-purpose cleaner (Photo 2). (Wear rubber gloves and eye protection.) Then rinse. If the infestation is particularly bad, you can disinfect the surface as well. It’ll keep the mildew from returning as quickly. To disinfect, mix 1/4 cup household bleach per gallon water. Mist the area with a garden sprayer or a smaller spray bottle. Don’t rinse off the bleach solution—let it dry on the surface. Caution: Handle bleach with care and never mix bleach with ammonia or an ammonia-containing detergent or cleaner—toxic gases may result.
Take steps to prevent mildew. Reduce moisture and promote better airflow around your house by limiting foundation plants and trimming back bushes. Make sure the water from sprinklers doesn’t hit the siding. And the next time you paint, check the label on the can to make sure the paint contains a mildewcide. Many exterior paints contain this, especially in regions with high humidity and dampness. If it doesn’t, ask the paint dealer (or the paint manufacturer) whether you can add some without harming the paint.
1. Test for mildew by dabbing on a little bleach. Rinse the area after a minute. If the dark stain has disappeared, you have mildew.
2. Scrub the mildewed areas with a stiff brush, hot water and a non-ammonia cleaner. Then rinse with clean water.
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