Tips for Painting Over Rotting or Weathered Wood

Are you thinking about painting your home’s exterior, but are worried the beat-up wood siding will complicate things?

Rotting and weathered wood siding is surprisingly commonplace, and while it does complicate the painting process, you’ll be happy to hear that it doesn’t make your home unpaintable. With a bit of time and effort, you can create a smooth surface to paint on.

To smooth out weathered siding, you first need to clean it up and smooth it out. You’ll also need to choose special paint and primer to ensure optimal results. It’s a lot of work, but that hard work is worth it in the end.

If you want to learn how to prepare damaged wood siding for painting, here are our expert tips for painting over rotting or weathered wood. In this guide, we’ll run you through the painting process one step at a time. Say goodbye to rot and wear and tear and say hello to a beautifully painted exterior!

Prepare the Surface

Paint won’t adhere to uneven or dirty surfaces. That means you’ll need to prep the wood to ensure the paint sticks to it. Prepping the wood takes a bit of effort and time, but it’s essential if you want your paint job to look clean and stunning. Not sure what prepping the wood entails? No worries. We’ll explain how to prep your wood surface step by step.

What if There’s Lead?

First thing’s first: you’ll want to make sure your exterior is lead free. If your home was built before 1978, there’s a chance there could be lead lurking in the walls. Lead paint is dangerous, so if you suspect you have it, get a lead paint test as soon as possible. If the test comes back positive, you’ll need to have the lead paint professionally removed before you can start painting.

Remove Rot & Flaking Paint

No lead? Great! Let’s move on to the next step. If you notice flaking paint or rot on your wood, you’ll need to remove it. You can remove flaking paint with a medium-bristle brush and a paint scraper.

Dry rot is a little more complicated to spot and treat. Dry rot results from microorganisms drawn to damp conditions. If you see dry, crumbly sections of wood or soft and soggy spots, it’s most likely rot. If you’re not 100 percent sure, drive the tip of a screwdriver into the wood—if it slides in easily, the wood is rotten.

To treat rot, start by applying a homemade bleach solution containing 10 percent bleach and 90 percent water. This will kill the microorganisms and stop the rot from growing. Next, remove all existing rot with a scraper. If there are any holes left behind, you can fill them with wood filler. Depending on the extent of the rot, however, you may need to replace entire wood boards. Using preservative-treated wood will prevent future growth.

After removing the rot from the wood, you should clean and apply fungicide to all surfaces within five feet of the rot. This extra precaution makes certain that the rot won’t come back.

Caulk Cracks

If there are seams or cracks in the wood, fill them with paintable and weather-resistant caulk. Use a caulking gun to apply the caulk and wipe away any excess with a soft and damp cloth.

Sand & Wash

Next, you’ll want to sand any areas that you filled with caulk or wood filler in addition to any heavily weathered areas. Use coarse sandpaper—40 to 60-grit is ideal—to make the surface smooth and even. Once you’re done sanding, bring out the power washer or a hose, because you’ll need to wash off all the sanding dust and any other dirt and grime still on the siding. After washing the surface, leave it to dry for three to four days.

The Best Painting Tools

Now that you’re done prepping the surface, head to your local hardware store and pick up some supplies. This list outlines the basic tools and supplies you’ll need for exterior painting:

When it comes to rotting or weathered wood, the primer is especially important. Primer comes in two forms: oil-based and water-based. Our tip for painting over rotting or weathered wood is to use oil-based primers, because oil primers seal the wood grains and prevent bubbling. Prime any filled spots first, and then work your way from the top of the exterior wall to the bottom.

The paint is just as crucial. A flat acrylic latex paint is ideal for weathered wood, while a high-gloss alkyd or oil paint will work well for trims.

Regarding paint brushes, you’ll want to get the highest-quality brushes you can afford. For painting on wood, we recommend using synthetic nylon and polyester brushes because they work better with oil and latex paints. They’re also less expensive, hold more paint, and create a smoother finish than natural animal hair brushes.

Prep & Paint

Now that you have your tools, you can start to paint. Start by prepping your work area. Set drop cloths on the ground, remove or cover all furniture, mask doors and windows with plastic sheeting, and apply painter’s tape as necessary. Using a nylon and polyester brush or a paint sprayer, paint your home from top to bottom. A top-down approach ensures paint drips won’t ruin the final look of your home. While there’s nothing stopping you from only applying one coat of paint, one or two extra coats will greatly increase the durability of your paint job and decrease the need for future repair work.

Does painting your home alone sound daunting? JK Paint & Contracting is an experienced group of painting contractors that serves Portland, Oregon, and the surrounding areas. Our team would be happy to help you paint your home. We’re experts in lead paint removal, dry rot removal, exterior painting, and more. Contact us today for a free quote and to discuss your vision for your home.

Thinking about painting your home, but worried the weathered wood siding will cause complications? Here are some tips for painting over damaged exterior wood.