We are often asked about the expected lifetime of a coat exterior paint. Our answer is usually the same. “It depends.” Paint is only as good as the surface it is applied over. The substrate often dictates the life you can expect out of a fresh coat of paint. Exterior painting on your house should be done approximately every 6-8 years depending on your siding material. Of course, several factors play into what causes your paint to flake, peel, deteriorate, or mildew and these factors can decrease the lifespan of the paint.
Moisture content is one of the largest factors that we encounter, especially when working on older homes. One of our best tools is a moisture meter. This helps us check the moisture content of wood materials to determine if paint can be applied. All of our employees have been trained to use the meter and are able to check various test spots to ensure that the paint can be applied. If you have cedar clapboards or shingles on your house, you may notice that the paint may bubble, flake, or peel. This often happens around windows or doors, but can happen anywhere on the surface. If water can penetrate through the siding through cracks, gaps in caulking, or even by holes made by carpenter bees, it can travel down the backside of the material and become trapped. As the sun makes its way across the different sides of your house, it heats the wood and subsequently draws the moisture out from the backside causing the paint to bubble or flake. Just last summer, we were asked to remove the remaining aluminum siding from a house built in the 30’s. The homeowner had already removed half of the siding on the house and wanted us to complete the other half. The siding covered beautiful, wide cedar clapboards and detailed decorative trim. It was no wonder that the homeowners wanted to uncover the treasure they had. Upon painting one side of their house, the homeowners found that after about a year, the paint they had applied had started to peel off in large pieces. On the opposite side of the house, we had noticed that after painting the clapboards by using the appropriate steps (preparation, priming, and finish coat), small bubbles had started to develop in certain areas. The moisture that had penetrated behind the siding and behind the cedar had started to work its way out during the hot summer days. The bubbles were addressed and we continued on with the job.
Another factor we encounter is improperly applied paint. If the previous finish coat or primer was applied improperly (in the rain, high humidity, finish coat on bare wood), it is possible that the life of the paint will decrease dramatically. One of our best practices is to make sure that the wood is properly prepared prior to applying primer. We make sure that the loose paint is removed from the wood by scraping with carbide scrapers and putty knives. A lot of time is spent on removing the old paint and preparing the substrate for a fresh coat. Even with this attention to detail, if the previous coat was improperly applied, the finish coat life may decrease. It is very important when you contract with a painting company, that you feel comfortable with the painting process and how the company approaches painting the house. Two years ago, we were contracted to paint a house in a nearby town. After applying a penetrating oil based primer, we were finding that some of the paint was bubbling. After speaking with the homeowner, we found out that the previous contractor had painted the house during several rainy and damp days. This moisture had become trapped in the clapboards and when our oil based penetrating primer was applied, it was forcing the moisture to the surface. The surface of these clapboards had been tested for moisture content, but our meter could not detect the moisture that was toward the backside of the clapboards. Unfortunately for the homeowner, this meant that we had to alter our initial painting plan and spend a great deal of time applying the primer, drawing the moisture out, scraping the bubbles down to the bare wood, and reapplying the primer. This extra time was necessary in making sure that our finish coat would not bubble, blister, or flake.
Substrate condition is another factor that will determine how long a paint job will last on your house. If you have clapboards or shingles that are rotted or have been sanded or scraped down in thickness, you may need to replace those pieces before the paint is applied. One of the best parts of our company is that we have the ability to take the paint job from start to finish, including all of the carpentry. We were contracted in the Spring of 2010 to complete a complete exterior restoration of the Webb House, which is a national historic landmark, on Main Street in Wethersfield. Approximately 1200 – 1400 square feet of siding was in need of replacement. We were able to replace the necessary clapboards and continue on with the painting portion of the project.
As more and more layers of paint are applied to a house, it becomes increasingly likely that the paint will peel or flake in the future. We are finding that one way to provide a good paint job is to chemically remove the paint layers that are built up on the siding material. This was the case at the Webb House and we were able to expose the raw wood of the clapboards. After removing the several paint layers, the house was washed, primed, and painted with two finish coats. By removing the excessive amount of paint on the house, we were essentially able to start with a clean slate. In doing this, the paint will last much longer than if applied over several layers of existing paint.
On a painting side note, it is a common misconception that it is not possible to paint both vinyl and aluminum siding. If you have either of these on your home and are looking to change the color, you don’t need to go through the steps of re-siding. It is possible to paint the siding on your home. In fact, the paint job lasts for a long period of time!
In order to prepare the siding on your home for paint adhesion, we will take several steps to ensure that the bonding of the paint will be as strong as if we were painting wood. The method we use has proven to last long, look fantastic, and be cost effective.