"Why even bother to paint your house? It won't last, anyway!"

The words of the vinyl siding salesman floated on the air, filling me with an intense anguish. The anguish wasn't for me; I was wise enough to see the holes in his argument. Instead, the anguish was for all those unsuspecting homeowners who would fall into his duplicitous trap.

Why does a house need repainting every so often? And make no mistake, even the best painting contractors won't deny that a fresh coat of paint is necessary eventually. What are the processes that require that attention be paid to that thin coating of paint on the outside of the house?

In my case, the paint was done in by ninety years: Ninety hot summers followed by ninety frigid winters. There were ninety years of children playing outside in the sun and ninety years of children trapped in the house by rain and snow. And ninety years of the elements doing their best to overcome man's most diligent attention--sun, rain, snow, wind, heat & cold. A little moisture let through cracks in the old paint caused larger and larger sections to blister, peel, and fall off the house. Along the way, absentee landlords and other owners who didn't know or care enough to invest the necessary attention undermined the efforts of thoughtful owners.

The paint on the outside of our house is a sacrificial layer that is there to protect the more expensive siding and mouldings underneath. As such, it is designed to ensure that the sun's rays and the rain's wetness don't penetrate into the more delicate interior. In order to accomplish these goals, the paint must meet certain requirements: It must be solid to prevent moisture and rain from penetrating; it must be flexible to move with the movement of the boards underneath as they expand and contract with temperature changes; it must be strong to stick to wherever it is applied; and it should be beautiful, too. And it must do all of this at the same time. Amazingly, our paints can do all that and more.

The key step in the painting process is surface preparation. It is what will make or break the final result, either ensuring a durable paint job or guaranteeing one that will fail before you can blink your eyes. Yet it is also the one that appears to be the most boring and the least rewarding.

In theory, we all know what we should do-scrape off the old, loose paint, wash off the dust left behind, and then we can get to the fun of watching our house be reborn under a layer of beautiful, fresh paint. We know that this is what we should do--but we don't really do it. And there lies the problem.

The difference between a properly prepared surface and one that just gets by isn't that obvious from afar. The miracles of a fresh coat of paint hide the underlying problems.

Step closer and the problem can be seen more clearly. A properly prepared surface will look almost brand new, only recently painted for the first time. Stripping all the old paint off to bare wood, light surface sanding, and proper priming make one doubt that this wall is really 92 years old. This is how it should look.

Other houses tell a different tale. Minimal scraping that was not smoothed out (feathered) results in a surface that almost screams out that it can't last. Although the new paint might adhere well to both the old paint and the wood siding, where the old paint and bare wood meet the new paint is sure to crack and fail.

Alligatoring is another cry for help from the old paint. The cause of alligatoring is that oil-based paints are never fully dry and continue to shrink as long as they are on the house. Eventually, even if it takes more than eighty years, a network of cracks develops that has this appearance. The thick layers of paint often found on houses that have been around for a century or so only exacerbate the problem. Left untreated, the new paint will soon exhibit the same problem and this will serve as a source for rain and moisture to get under the paint layer and cause future peeling.

There are even some owners who don't bother scraping at all, figuring instead that the new paint will somehow stabilize the old, fill in all the cracks, and last for another 100 years. Unfortunately for them, it is wishful thinking.

How should we treat our wood siding, which is much more beautiful than vinyl or aluminum could ever be? You should begin by preparing the area where you are going to be working. Cover the adjacent bushes with tarps to catch paint flakes, check for areas that need whole boards to be replaced, and break the job into easily managed portions. The temperature should be above 50F for the duration of the job and for several days afterwards. Check the recommended painting conditions listed on the paint can.

Be cautious also: old paint probably will contain lead, which can cause problems in humans, especially if it is ingested by little children. Lead poisoning can also cause problems in adults and a wise person will do what they can to avoid unnecessary exposure. Care should be taken to pick techniques that will result in as little lead dust becoming airborne as possible. An additional precautionary move would be to get a blood lead assay conducted prior to and then again following the scraping and painting. This will then allow you to determine how much you were exposed to the lead.

1. Manually scrape off the loose and flaky old paint. DON'T use a power washer because it will chew into the wood underneath and that damage will be virtually impossible to repair. The best tools and techniques to use depend on nature and the magnitude of the job at hand. A good quality hand scraper with a blade that can be resharpened works well to loosen and remove paint. A cheap little scraper bought at the local "Dollar store" often is more trouble than it is worth. For the brave at heart, a heat gun can be used to soften old paint so that it can be completely removed down to bare wood. This last process, however, requires lots of time, patience, and care to not burn down the structure to the ground.
2. Feather out the edges left at the margins of the old paint so that you have a smooth surface. Use medium-grit sandpaper on a sanding block and smooth the edges of the paint. What you are trying to achieve is a surface that does not have sharp edges or breaks where the paint meets exposed wood. Be careful of lead dust. Use a dust mask or a respirator with a HEPA filter on it to prevent inhaling the lead dust. See the article by Ray Ramirez in the November 1999 issue of Old House Chronicle for more information.
3. Wash with trisodium phosphate (TSP) to thoroughly clean the dust off the surface. TSP should be available at most paint stores or home centers. As it washes, it will actually bind the dust and lead that are present and allow them to be removed from your surface. Remember, if the dust is left behind the new paint won't stick to the surface. Following the TSP wash, rinse the surface by hand with clean water. Change your water frequently so that the rinse water is clean. Take the time to let the surface dry, but don't wait too long or else airborne dust will settle on the siding and you will have to wash again. If the weather is sunny and it doesn't rain, one week will probably be enough. If you have sprayed your house with a hose to rinse it, you might have to wait much longer.
4. Prime with a high-quality primer (Remember: you get what you pay for). For old houses, oil-based primers may be better than latex because they will penetrate into the wood and condition it, replacing the wood's natural oils that have been lost over the years. Many painters, including me, prefer a brush for application of the paint because it covers uniformly and gets into every nook and cranny. A good quality brush may cost $20-25, but it can last a lifetime if properly maintained. The goal at this step is to uniformly cover the entire surface with the primer, leaving you ready for the next step.
5. Top with two coats of a high-quality paint. Again, you get what you pay for and materials end up being only a small portion of the total cost of the project. Modern latex paints may offer the best option for your topcoat. They allow you to apply a uniform paint layer directly over the oil-based primer. They weather well and offer an ease of application that is desirable. Again, a brush works well to uniformly spread the paint and ensure adequate coverage. For latex paints, be sure to buy a synthetic bristle brush instead of a natural bristle brush because the natural bristles will absorb the water from the paint and the brush will eventually be ruined.
6. Conduct yearly maintenance: look for loose paint areas, spot scrape, sand, prime and finish them. This maintenance is to ensure that the outer layer of the house stays intact. If you skip this step, the inevitable small cracks and flakes in the paint layer will allow moisture and water to pass into the wood underneath and eventually the entire paint job might be ruined. Although it seems tedious, this is an important component of the whole process.

With some attention to detail, wood siding will continue to provide protection and elegance to your house for your lifetime and beyond.

Additionally, with periodic check-ups and occasional painting, it will be more beautiful and less expensive than the imitation plastic (vinyl) or aluminum sidings on the market. For additional information, the Journal of Light Construction (March 2000) has a wonderful article on paint stripping and repainting of architectural woodwork using commercial strippers. Check them out at www.jlconline.com.