Paint Prep Power: Make Your Exterior Paint Last Longer

Prep work isn’t optional—it’s essential. No matter how premium your paint is, whether it’s Benjamin Moore or Sherwin-Williams, it won’t perform unless it’s applied over a properly prepared surface.

Whether you’re repainting wood siding, stucco, trim, or brick, the success of your project hinges on paint prep. Below, we break down what happens when you skip it, why each step matters, and what pros know that DIYers often overlook.

The High Cost of Skipping Surface Prep

When paint is applied to a surface that’s dirty, glossy, chalky, or peeling, it simply can’t bond properly. The result? Visible failure—and often, much sooner than you think.

Paint Failure from Poor Prep: What It Looks Like and Why It Happens

Step 1: Scraping—The First and Most Crucial Move

Scraping is your starting point for removing any paint that’s already loose or peeling. It ensures your new coat isn’t just sticking to a layer that’s about to fall off.

Scraping Tips

• Use a stiff scraper or a pull scraper for large clapboard areas.

• Apply consistent pressure at a shallow angle.

• Wear a dust mask—especially for homes built before 1978 due to potential lead paint exposure.

Failing to scrape properly is like building on a cracked foundation—everything on top is at risk.

Step 2: Sanding—Smooth It Out, Dull the Gloss

After scraping, sanding creates a smooth transition between painted and bare areas. It also removes residual gloss or surface chalk that interferes with paint adhesion.

Choosing the Right Sandpaper Grit

For large areas, a palm sander or orbital sander reduces manual labor and provides a more even finish.

Step 3: Repairing—Don’t Paint Over Problems

In paint prep, repairing damaged surfaces is crucial. Surface flaws such as nail holes, cracks, wood rot, or popped nails are not just cosmetic concerns—they are gateways for moisture to penetrate your home’s exterior. Moisture intrusion can silently undermine your paint job, causing peeling, bubbling, and premature failure.

Nail holes and gouges

Use an exterior-grade wood filler designed to withstand outdoor conditions. Apply it smoothly to fill gaps and imperfections, then sand for a flush finish. This ensures the repaired spot blends seamlessly with the rest of the siding or trim.

Rotten wood

If the wood is soft or crumbling, it must be replaced entirely. Painting over rotten wood is a mistake—paint won’t adhere, and moisture will continue to damage the area beneath the surface. Replacement boards provide a solid foundation for primer and paint.

Cracked stucco

For stucco surfaces, use a patching compound specifically formulated for stucco repair. Properly filling cracks prevents water from seeping behind the finish, which can cause more extensive damage over time.

Loose nails or screws

Any nails or screws that have popped out need to be reset and countersunk. This keeps trim and siding secure and prevents movement that can crack paint or cause gaps where moisture can enter.

Step 4: Re-Caulk Where Needed

Caulking seals joints where two materials meet—like siding and window trim—and keeps moisture out. Cracked or missing caulk should always be replaced before painting.

Best Practices for Caulking

• Use a flexible, paintable caulk (preferably acrylic latex with silicone).

• Completely remove deteriorated caulk with a utility knife or painter’s tool.

• Smooth the new caulk with a damp finger or finishing tool for a clean look.

• Let it cure fully before priming or painting.

Step 5: Priming—Your Paint’s Best Ally

Primer is essential for sealing repaired areas, bare wood, and chalky surfaces. It ensures uniform paint absorption and long-lasting adhesion.

When You Must Prime

Apply primer evenly, allow it to dry fully, and check for missed spots before applying paint.

Step 6: Don’t Skip Lead Paint Testing

If your home was built before 1978, there’s a significant chance it contains lead-based paint. This presents a serious hazard during paint prep. Sanding or scraping lead paint without proper safety measures can release toxic lead dust into the air, posing health risks to you, your family, and neighbors.

How to Identify if Lead Paint Is Present

Before you begin any scraping or sanding, it’s critical to confirm whether lead paint is present. The simplest way is to use a lead test swab, which you can buy at most hardware stores. These swabs provide a quick indication, allowing you to make informed decisions about your paint prep process.

Following EPA Lead-Safe Renovation Rules

If lead is detected, the Environmental Protection Agency’s Renovation, Repair, and Painting (RRP) rule comes into effect. This federal regulation requires special work practices designed to minimize lead dust and contamination during surface preparation. These include containment, proper cleanup, and use of protective equipment.

Why Hiring an EPA-Certified Contractor Matters

For homes with confirmed lead paint, paint prep and removal should never be a DIY project. Hiring an EPA-certified contractor ensures the job follows all safety regulations, protects your household’s health, and prevents lead dust from spreading to surrounding areas.

Step 7: Wash the Surface—But Don’t Stop There

Cleaning removes dirt, mildew, and chalk, but doesn’t replace the need for scraping, sanding, or priming. Washing is the start of paint prep—not the whole story.

Washing Guidelines

Always allow at least 48–72 hours for surfaces to dry before painting.

Step 8: Masking and Protecting Adjacent Surfaces

Prep isn’t just about what you’re painting—it’s also about what you don’t want to paint. Masking protects windows, trim, landscaping, and fixtures from overspray and drips.

Three Key Masking Tools

1. Drop cloths – Protect walkways and plants.

2. Painter’s tape – Create crisp lines and prevent accidental splashes.

3. Plastic sheeting – Cover large areas like decks or masonry.

Don’t rush this step—a careful masking job saves hours of cleanup.

Step 9: Final Pre-Paint Inspection

Before the first coat goes on, take one last, slow walk around your home. Use this checklist to ensure nothing was missed:

• Are all peeling or glossy areas sanded?

• Have all repairs cured and been re-sanded?

• Is all caulk dry, clean, and smooth?

• Have you primed every bare or patched area?

• Are your surfaces dust-free and fully dry?

If every answer is yes, you’re officially paint-ready.

Why Smart Paint Prep Pays Off

Taking shortcuts with prep is the fastest way to waste good paint and labor. But when you do it right? You get a smooth, durable, weather-resistant finish that stands the test of time.

Benefits of Proper Paint Prep:

Want Help With Paint Prep and Exterior Painting?

We don’t paint over problems—we solve them first. Our crew handles every detail of your exterior paint prep, from scraping and sanding to priming and protection. No shortcuts. No guesswork.

Call today for your free exterior painting estimate. Let’s prep it right—and paint it to last.