How to Prepare Outside Surfaces for Painting: Getting It Right the First Time

Preparation: (At Least) Half the Battle

Like the proverbial iceberg, an exterior painting project involves more than meets the eye. For every hour spent applying paint, an hour was likely spent preparing the surfaces to receive it. Choosing excellent materials is key to a successful paint job, but so is prep work. Neglecting it can make maintenance much more difficult than it needs to be.

Over time, natural light and extreme temperatures can wreak havoc on exteriors that haven’t undergone the right preparation. To know what must be done, you have to inspect your house from top to bottom, noting spots in need of repair along the way. Doors, windows, wood trim, and fascia boards are the usual suspects, but be on the lookout as well for cracked or decaying wood. Bonding glue and epoxy wood filler can help shore up trouble spots.

An Ounce of Prevention is Worth a Pound of Cure

There are many ways to protect a home from the elements. Implementing them now can forestall difficulties down the line. Caulk may not be enough to keep rain and ice from doing harm. Metal flashing — sheet metal used to waterproof — is a stronger defense, especially when it comes to fascia boards. Ideally, the metal covers the fascias and channels rain and melted snow into the gutters.

When applied to windows and doors, flashing is known as “drip edge.” It’s usually incorporated when a home is first built. Newer houses are more likely to have it; their older counterparts may have nothing but caulk to keep out the wet.

If water is leaking in, paint in the area of the leak may show it. For example, it might peel, blister, or become discolored. Eventually, a moisture buildup can also lead to mold and mildew. Neither of these is conducive to treating a surface with primer, so they have to be taken out. All repairs related to the leak must also be completed before primer can be used. Getting rid of mold and mildew isn’t enough, of course; they cannot be allowed to return.

How to Prepare Exterior Surfaces

Paint on the outside of a house can develop chalk deposits. Fortunately, pressure washing can eliminate them. As a rule, if surfaces aren’t clean, they aren’t ready to be painted. If the exterior of your home consists of stained siding, you’ll want to take a slightly different tack, but pressure washing is still an option.

To take unsightly old paint off a surface, you must scrape and sand it. These methods complement each other; if neither is sufficient to remove everything that needs to go, together they almost certainly are. A wire brush, or a power drill with paint-stripping attachments made of wire, is necessary if you’re working with a rough wood, like sawn cedar. Taking off old paint may be a chore, but it’s crucial. The condition of the surface will determine the project’s success more than anything else.

Houses constructed before 1978 may include lead paint. Thus, scraping and sanding the exteriors of such homes must be done with care. Lead paint dust and chips can cause significant health issues, so it’s essential to learn how to proceed safely before beginning this phase of a paint job.

Your exterior painting project will also require you to caulk, mask, and prime surfaces. It’s best not to cut corners, cost-wise, when choosing the relevant materials. When you’ve finished these steps, it’s finally time to paint! That said, picking the right paint, and the right ways to apply it, takes some thought as well.

Well-Prepared Exteriors Become Well-Painted Surfaces

If you’re hiring a pro, exterior prep ought to be part of the project plan. Many contractors can fix damaged areas as well, which saves you the trouble of finding (and paying) two firms to do one job.

Some projects require a building inspection and/or permit. Many cities have a department of building services to carry out these duties. It may also be helpful to familiarize yourself with construction codes specific to your area. (Washington state’s, for example, is located online at

If you follow the steps listed above, or ensure that a contractor does so, your exterior paint may last more than a decade. For that reason, it’s well worth expending time in the present to create a better future for your home.

  • freedom painters

    Which chemical can I use to treat water walls before painting

    • JPB

      I have not had problems with chlorine bleach

  • Lonnie Wishart

    How do I get this plant remains off cedar shakes and concrete? Want to paint. Pressure wash didn’t get it off. Also how do you scrap rough cedar shack siding?

    • carl

      Hi, it might be that your pressure washer wasn’t quite up to the job but you could use a good cordless drill with a wire brush head or even a wire brush. An angle grinder can also be used with a wire brush attachment but wear protectI’ve gear as they can jump out of the strongest grip when using on wood. Good luck

      • JPB

        I would use chlorine bleach, apply, let sun dry, rinse with water and let dry before doing any further applications (if required)