Seven Deadly Sins of Exterior Painting
Exterior painting is a great way to maintain and beautify the wood siding on a home, but it’s important to do things correctly. Commit any one of seven painting “sins” and you may suffer the consequences: a shortened life for your brand new paint job. According to Debbie Zimmer, spokesperson for the Paint Quality Institute, these are the seven sinful painting practices that can punish paint performance.
1. Failure to smooth rough edges on old paint. Good surface preparation is vitally important when doing any kind of painting. After scraping away loose, flaking or peeling paint, the old paint that remains will probably have rough edges. If these edges aren’t sanded properly, the new paint will flow over them in a very thin coat, creating areas that are vulnerable to failure.
2. Failure to properly prepare weathered wood. Painting bare wood that has been exposed to the elements for even a few weeks can lead to cracking and peeling after only a year or two. Zimmer says this problem can be avoided by thoroughly sanding the weathered wood, then priming (see sin #3), before applying any paint.
3. Failure to use a primer. Almost any exterior paint job will benefit from a coat of primer, but it’s especially important to prime wood that has not been previously painted. The same holds true for any wood that has no paint – either because it has peeled or flaked off, or because of rigorous scraping and sanding during surface preparation.
4. Failure to correct a source of moisture behind the wood. According to Zimmer, moisture seeping behind the paint can result in blistering and peeling. Careful caulking can resolve most of these issues. Among the areas to check are open seams at corner joints and anywhere windows and doors abut the walls. Splits or cracks within the siding should also be sealed with paintable siliconized acrylic caulk. If any wood seems structurally unsound, it’s wise to call in a pro to make sure it doesn’t have to be replaced.
5. Failure to apply paint at the proper spread rate. Paints perform best when applied at the recommended spread rate. Trying to economize by either thinning paint or applying it in too thin a coat can invite a variety of early paint failures, most notably, cracking and peeling; it can also result in greater susceptibility to mildew formation.
6. Failure to apply latex paint in the right weather. Applying latex paint when the outside temperature is very cold can keep it from adhering properly; on the other hand, applying it in extremely hot weather can impair the durability of the paint film. Painting when rain is expected within 24 hours or so, or when heavy dew is expected, can also lead to early paint failure.
7. Failure to use the correct type and quality of exterior paint. It goes without saying that outside surfaces should be painted only with exterior paint. But the type of paint used is important also. According to Zimmer, top quality 100% acrylic latex paints provide the best overall performance. . . and the best protection against premature paint failure when applied to properly prepared wood surfaces. “These paints cost somewhat more than run-of-the-mill exterior paint, but they last a lot longer and often require fewer coats,” says Zimmer. “That makes them a relative bargain for cost-conscious homeowners.”
If you want your paint to last, cast off that careless attitude and follow good painting practices. Your reward will be a long-lasting exterior paint job in the here and now.