How Do You Prepare House Trim for Painting?

Oct 31, 2022

Painting the exterior trim on your home is a great way to give it a new and improved look. Before you start painting, it’s important to properly prep the wood so you achieve the best results. Here’s how to prepare house trim for exterior painting.

Why Preparing Exterior Trim is Important

Preparing exterior trim before you start painting is crucial for a high-quality paint job. Cleaning and repairing it prior to painting ensures you don’t paint over dust, dirt, and other debris so the paint goes on smooth. It also helps the new paint bond with the trim so the paint lasts longer and looks nicer. Each step in the preparation process is important for helping the exterior of your home looks its best.

Step 1: Make Sure You Have the Right Painting Supplies

The first step in prepping exterior trim before painting is to make sure you have all the right supplies. You will need tools to help you wash the exterior wood trim, such as a sponge or pressure washer. Be sure to also have water handy. To remove any old or peeling paint, you may need tools like a paint scraper, sandpaper, power sander, or wire brush. When it’s time to repair damaged areas of the wood, you’ll need a spackling compound. Caulk and a caulking gun are also important for the preparation process.

Painter’s tape will help ensure you don’t get paint where you don’t want it, such as on masonry or siding. A high-quality exterior primer is crucial for ensuring the new paint looks nice and properly adheres to the wood. Angled paint brushes will help you achieve a quality paint job. You may also find it helpful to have tools like a ladder, spackling knife or putty knife, paint sticks, paint trays, and tarps.

Clean the Exterior Trim of Your Home

A tip for before you paint outdoor trim is to be sure to clean it so there’s no dirt and grime present when painting. Contaminants like dirt, oil, rust, loose paint, mildew, mold, and more on the exterior of your home can prevent new paint from looking great and properly adhering to exterior trim, so removing it before painting is important. There are a few different ways to do clean the wood. You can use a damp sponge to wipe contaminants off the surface of your home’s exterior. A scrub brush may also be effective. You can also use a pressure washer to more forcefully remove contaminants.

Avoid Lead Exposure

Houses built before 1978 may have exterior siding that was painted with lead paint. Removing lead paint, whether by scraping, sanding, or some other method, can cause lead dust to appear. Lead dust can cause brain damage and other health issues, especially in children and pregnant women. If your home is at risk for containing lead paint, be sure to use a respirator when painting. Better yet, contact a contractor who is experienced in lead paint removal so you can continue your exterior paint project without the hazard of toxic lead paint or dust.

Allow the Exterior to Dry

After washing the exterior trim, give it time to dry before painting. This will make it easier to scrape off remaining paint and help prevent damage to the wood. Allow the wood to dry for a day or two before continuing with the preparation process.

Sand the Trim

Once the exterior trim has dried, you can begin sanding it. This will create a smooth surface for the new paint to adhere to, helping the paint look nicer and last longer. If the trim is old or in rough condition, start with a course sandpaper, such as 80-grit sandpaper, before moving to a finer sandpaper, like a 100-grit sandpaper. If it’s new or is still in good condition, you can skip the course sandpaper and sand the trim using the finer sandpaper. Then, remove any dust by wiping the exterior trim with a damp sponge.

Remove Peeling Paint

Before painting exterior wood trim on your home, it’s important to remove the old paint. There are a few different ways to do this. You can scrape off the paint by hand using a paint scraper or a metal wire brush. You can also use a power sander with the proper attachment for paint stripping on exterior materials.

Spackle Holes in the Wood Trim

When painting exterior trim, you want to have a smooth surface. In addition to sanding and paint removal, it’s important to fill in any holes or cracks with spackling product or wood filler.

Sand the Spackle

Once the spackle has dried, sand it using a fine sandpaper to remove any bumps and ensure you have a smooth surface for painting. Remove sanding dust with a tack cloth to prevent the dust from getting caught in the new paint.

Apply Caulk

Applying caulk between the trim and the exterior wood siding of your home helps prevent water from entering the seams and causing problems. Before applying caulk, remove any old, dried out caulk. Then, add new caulk anywhere pieces of trim come together and where it meets the exterior siding of your home.

What Type of Caulk Works Best?

If you plan on painting over the caulk on the exterior of your home, it’s best to use a latex caulk on the exterior surfaces.

Apply Painter’s Tape to Protect Exterior Wood Siding

Before you paint exterior trim on your house, it’s helpful to apply painter’s tape to protect areas where you don’t want paint, such as siding or masonry. Choose a painter’s tape designed for use on the exterior of the home, as it more easily sticks to surfaces like siding and brick than regular painter’s tape that you would use inside the home. Press a few inches of tape to the exterior, then hold that end of the tape in place while you pull out a few more inches of tape, then secure the tape to the surface of the siding or brick. Place the tape as close to the trim as you can without going over it.

Make Sure the Tape Sticks

Once the tape is on the siding or other exterior surface of the home, press it down using a clean putty knife or spackling knife to ensure there are no gaps between the siding and the tape. This helps prevent paint from dripping under the tape and making a mess on your home’s exterior.

Paint Primer onto the Trim

If you want to paint your home’s exterior like a pro and make sure the new paint color looks its best, it’s important to first paint trim with a primer. This seals and protects the wood and helps the paint better adhere to the wood. Make sure you can easily reach the exterior area you’re priming and use a ladder or step stool if needed.

Use an Angled Paint Brush

To achieve the best results, use an angled brush. Stir the primer with a paint stick, then pour some into a paint tray or securely attach the paint can to your ladder. Dip the angled brush about ½ inch to 1 inch deep into the liquid and wipe off any excess using the side of the tray or can to prevent drips. Then, apply a coat to the wood.

Allow the Primer to Dry

Different exterior primers need different amounts of time to dry before you start painting color over them. Latex primers typically dry in an hour or so. Oil-based primers tend to take longer, and you should wait 24 hours before painting over it. Whichever type you choose, it’s best to allow primers to dry for several hours before covering them with paint color. To paint like a pro, follow the instructions on the container to ensure you’re giving primers enough time to dry.

Paint on More Primer if Needed

If spackle or bare wood is still visible after the primer has dried, paint on a second coat. Allow the second coat to dry before adding paint color.

Let Prim Painting Prepare and Paint Outdoor Trim

Preparing the trim on the exterior of your home for painting requires a lot of time, energy, and supplies. Don’t want to do it yourself? Contact the painting experts at Prim Painting. Our team has years of experience giving homes a new and improved appearance and can help your home look its best. We will prep and paint the trim on your home and can handle any other exterior or interior painting needs you might have. We offer residential and commercial painting services in Columbus, Ohio and throughout the Central Ohio area. We look forward to assisting with your next painting project.

Contact Us

Contact Prim Painting at (614) 686-7746 or fill out our online contact form to learn more and get a free estimate.