When working on historic homes, especially those built in the early 1900s, understanding how to properly prep and paint old wood siding is crucial. As someone who has spent years restoring character and heritage houses, I want to share some essential tips and insights about dealing with old wood siding — specifically how to recognize when your siding needs stripping, how to prep properly, and the best practices for priming and painting.
Recognizing the Condition of Old Wood Siding
One of the first things to look for when assessing old wood siding is the visibility of the wood grain beneath the paint. Ideally, you should still be able to see the wood grain clearly, as this indicates that the paint and primer are still adhering well to the wood surface.
When you start to lose the wood grain visibility and see areas where the paint has peeled off—especially in patches covering 50-70% of the surface—this is a red flag. The wood beneath often appears darker, which means the paint is no longer properly bonded to the surface, and the original primer is failing. At this stage, the paint can often flake off quite easily with a scraper or putty knife.
Another sign that your siding may need complete stripping is the appearance of micro cracks on the wood surface. These tiny cracks show that the paint is no longer protecting the old wood, and the coating has lost its integrity. When this happens, sanding might help smooth out edges, but a full strip and repaint might be necessary for a lasting finish.
When to Consider Stripping Your Wood Siding
The general rule of thumb is if you notice about 50 to 70 percent paint failure on your siding, it’s time to consider stripping it completely. This ensures that you’re not just covering up damaged paint but addressing the underlying wood condition for a proper, durable finish.
Common Issues When Siding Meets Rooflines
One of the most common problems I encounter in older homes is siding installed directly against the roof without a proper gap or flashing. This setup causes paint failure and wood damage over time due to water exposure.
When siding touches the roof, water running down the shingles can get absorbed into the end grains of the wood siding, leading to splitting and deterioration. You might notice multiple boards with splits, cracks, or even boards opening right up, which makes it difficult to get primer applied evenly on those edges.
For anyone installing new siding, it’s critical to ensure there’s a gap between the siding and the roof to allow airflow and proper drainage. Flashing behind the siding is also essential to protect the wood from moisture intrusion. Unfortunately, many older homes didn’t have these details done correctly, which means extra care is needed when prepping and repairing these areas.
Priming Old Wood Siding: Use Oil-Based Primer
When prepping old siding for painting, especially on heritage homes, I always recommend using an oil-based primer. This type of primer adheres better to aged wood and provides a stronger protective barrier before applying the topcoat.
After scraping and sanding the siding, especially in those tricky corners and edges, a good coat of oil primer will seal the surface and help the paint stick better and last longer.
Keep in mind that weather conditions can affect your work. For example, if it starts raining or gets dark, it’s best to pause and protect the siding with primer to avoid exposing the wood to moisture.
Final Thoughts on Maintaining and Restoring Old Wood Siding
Old wood siding on character homes is beautiful but requires thoughtful preparation and maintenance. Always assess the paint condition by checking the wood grain visibility and look out for paint failure signs like flaking and micro cracks.
Ensure proper installation details, especially around rooflines, to prevent moisture damage. When priming, oil-based primers are your best bet for durability.
Taking these steps will help preserve the charm and integrity of your heritage home for years to come.
