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Exterior Painting Pointers

Partner Post: Maine Preservation

In a monthly column, Christopher W. Closs, an expert with Maine Preservation, answers your questions about maintaining antique and vintage homes.

Q. I live in a seaside clapboard house built in 1856. Three sides of my home need repainting desperately, as bare wood is showing where paint has peeled off. What are the considerations I should be aware of in repainting a building of this age? How can I ensure the most durable finish?

– M.G. Sly, Brooklin

A. When it comes to painting old houses, careful preparation is of paramount importance. Keep the three Cs in mind before you apply a lick of paint to those clapboards: Condition, Carpentry, and Conservation.

Condition

If, as you write, there’s virtually no paint adhering to some of the clapboards, check the condition of the wood. Is there moss or mold growing? Do the clapboards feel wet? Is the wood cracked, damaged, or missing?

Any moisture problems must be addressed before you start painting. Typical causes of water damage to clapboards include leaking roof eaves, backed-up gutters, poorly vented kitchens or baths, dirt basement floors that permit moisture to rise up and penetrate all areas of the house, and concrete basement floors poured without a vapor barrier (frequently the case in homes built before 1975). Installing bathroom and kitchen fans is a simple and inexpensive solution to many excess moisture issues. It’s also easy to cover a dirt basement floor with plastic sheeting. For concrete floors lacking a vapor barrier, consider applying two coats of a vapor-barrier paint or investing in rubber matting that can be rolled into place.

To deal with other types of deterioration, follow the tips below.

Carpentry

Skilled carpenters can replace missing and cupped clapboards, repair areas where knots have fallen out or cracks have developed (where the clapboards meet the trim, for example), and reset nails that have popped out, a problem most often seen on south- and west-facing walls that take a beating from the sun.

Conservation

Bare, severely weathered clapboards punished by the intense rays of the sun won’t be able to absorb or hold paint. In this case, it’s useful to apply a conservation treatment like Smith’s Clear Penetrating Epoxy Sealer or Penetrol Oil-Based Paint Additive to penetrate, revivify, and help reinforce the wood fibers prior to painting. If you notice any mildew on your clapboards, look for Bora-Care, a liquid solution that retards mold growth.

Now that your clapboards are stabilized, you can proceed with the three Ps: Prepping, Priming, and Painting.

Prepping

You’ve likely heard about the serious health dangers associated with flaking lead-based paint — a product commonly used on houses built prior to 1978 — and dust. When scraping and sanding paint from any older home it’s essential to use common sense and scrupulously adhere to local codes about lead paint safety and abatement. Painting contractors must be EPA-certified and properly protected when removing and disposing of lead paint. If you elect to do any of this work yourself, you must wear a high-quality respirator (replace the filters once or twice daily), gloves, and goggles. Spread tarps at least 10 feet back around the apron of your home to collect all of the old paint. Your local recycling center can advise you on proper paint disposal.

Don’t worry about removing 100 percent of the old paint from clapboards. Where paint adheres, leave it be. For areas with peeling paint, hand scraping with a carbide blade and sanding to “feather in” surfaces are appropriate. (Some contractors recommend pressure-washing first to remove dust, mildew, and paint flakes, a process that can result in moisture getting trapped in cracks and behind walls. If you choose this option, make sure to schedule at least two weeks of drying time prior to priming.) You may also opt to use infrared-heated paint removal tools to soften the paint and minimize lead dust and vapors at a safe temperature. Under no circumstances should you permit the use of open-flame tools. They can ignite hidden dust and debris and set a house on fire. At Maine Preservation, we also strongly recommend against rotary sanding tools, which can leave unsightly crescent-shaped divots on clapboards that are very difficult to remove.

Priming

To prepare surfaces for priming, caulk thin longitudinal cracks with paintable silicone and apply an epoxy filler to larger holes. Next, consider applying two coats of primer tinted one shade lighter than your finish coat. Yes, two coats are more expensive, but they will improve the adhesion and endurance of the finish paint. If you notice that your clapboards are marked by ridges and striations, opt for a “high-build” primer designed to fill imperfections. For bare wood, we recommend an oil-based primer, which delivers superior penetration. To ensure your coats cure properly, make certain that day and nighttime temperatures are not forecasted to fall below 50 degrees. It’s also important to brush out the primer, even if you use a roller or sprayer to apply it, to create a strong bond with the wood.

Painting

Finally, you’re ready to paint! If you’ve used a tinted primer, you can usually get away with one finish coat. Stick to the same brand for your primer and paint — they are formulated to work together — and follow the application instructions above.

You’ll likely be asked about oil vs. latex paint. The good news is that recent formulations of latex paints are more durable than in the past, so the choice is up to you. Just remember this rule: latex can be applied over oil, but oil cannot be applied over latex. So if you have latex primer or paint on your house already, you’ll have to stick with latex going forward (or remove all of the old latex paint). Unsure of what’s currently there? Take a sample to your local, established paint dealer for identification.

One last point: Certain salespeople may try to convince you that vinyl siding is appropriate for old houses, but it’s not! Synthetic siding materials are simply incompatible with historic buildings, so just say no!

For more information on painting historic houses, check out this “preservation brief” published by The National Park service or contact us with questions.

Cover image: The 1858 Captain Reuben Merrill House in Yarmouth, home to Maine Preservation, was hand-scraped and coated with an oil-based primer and latex paint last summer.

Christopher W. Closs is field service advisor for Maine Preservation, the only nonprofit historic preservation group working to preserve and protect treasured places across the state of Maine. Closs holds a Master’s Degree in Historic Preservation from the University of Vermont and is skilled in restoration carpentry and stone masonry. You can email additional questions to Chris@mainepreservation.org and find more helpful information at mainepreservation.org.


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