Preparing a house for exterior paint means three things in order: checking for lead paint hazards if your home was built before 1978, cleaning and repairing the surface so paint has something solid to grip, and picking a paint and weather window that match your climate. Skipping any one of these steps is the most common reason an exterior paint job fails early. This guide walks through each stage and tells you where to stop and call a professional.
Stop and check this first: lead paint on older homes
If your home was built before 1978, treat this step as non-negotiable before any scraping, sanding, or pressure washing begins. The U.S. Environmental Protection Agency (EPA) reports that nearly thirty percent of homes in the United States, mostly those built before 1978, have lead-based paint. Disturbing that paint through scraping or sanding can release lead dust that is dangerous to children and adults.
- Find out your home’s age. If you don’t know when it was built, your county assessor’s office or property records can usually tell you.
- Assume lead paint is present if you can’t confirm otherwise. The EPA advises that if you cannot determine your home’s age, it is safest to assume the area you’re working on has lead-based paint.
- Hire an EPA or state lead-safe certified firm for pre-1978 homes. The EPA’s Renovation, Repair and Painting (RRP) Rule requires that contractors working on pre-1978 homes be lead-safe certified, and EPA recommends homeowners hire a lead-safe contractor certified and trained in lead-safe work practices even for repaint jobs.
- If you plan to do the prep work yourself, the EPA publishes specific lead-safe work practices for do-it-yourselfers, including how to contain dust and clean up safely. Review that guidance before you touch a painted surface.
This is not a step to shortcut or do “carefully” without the right setup. Lead dust is invisible and settles into soil and household dust, where it can affect a household long after the project is done. When in doubt, get your paint tested or hire a certified lead inspector before you start.
Other safety hazards to rule out before you start
Beyond lead paint, a few conditions call for a licensed professional rather than a DIY approach:
- Working above one story or on a steep roof line. Ladder falls are a leading cause of home-project injuries. If the job needs scaffolding or extended ladder work, consider hiring a licensed painting contractor.
- Rotted or soft wood siding, trim, or fascia. This can signal a structural or moisture problem behind the surface. A general contractor or structural specialist should assess it before painting over it.
- Visible mold or persistent damp staining. Painting over active moisture problems will not solve them and can trap the moisture. Address the water source first.
- Old wiring, exterior outlets, or fixtures in the work area. Leave anything electrical to a licensed electrician.
Permit rules for exterior painting are usually minimal, but some historic districts, homeowners associations, and municipalities regulate exterior colors or require notice for scaffolding. Check with your local building or planning department before you start, since these rules vary by city and county.
Surface preparation checklist
Once you’ve cleared the lead-paint and structural checks above, surface prep is what makes paint last. Work through these steps in order:
- Wash the surface. Dirt, pollen, and mildew keep paint from bonding. A garden hose and stiff brush handle most homes; a pressure washer works faster but can force water behind siding if used incorrectly, so keep the nozzle at a safe distance and angle water downward on lap siding.
- Scrape loose or peeling paint. Remove only what is already failing. If your home is pre-1978, use the lead-safe methods referenced above, or have a certified firm do this step.
- Sand rough edges. Feather the edges between old paint and bare wood so the new coat doesn’t show a ridge. Again, follow lead-safe practices on older homes.
- Repair damaged wood and caulk gaps. Fill small holes and cracks with exterior wood filler, and caulk gaps around trim, windows, and doors with a paintable exterior caulk. Skip this step on any area where you suspect rot until it’s been assessed.
- Spot-prime bare wood and repairs. Bare wood and patched areas absorb paint differently than the surrounding surface. A primer coat evens this out and helps the finish coat look consistent.
- Let everything dry fully. Painting over damp wood or a surface that was just washed traps moisture under the new coat, which can cause peeling later.
Choosing paint for your climate
The right exterior paint depends more on your local weather patterns than on brand. A few general guidelines:
- Hot, sun-heavy climates: Look for paint labeled fade- and UV-resistant, since intense sun exposure breaks down pigment and binders faster.
- Humid or rainy climates: Mildew-resistant exterior formulas help slow the growth that thrives in damp, shaded areas like north-facing walls.
- Cold climates with freeze-thaw cycles: Paints formulated for flexibility hold up better as wood expands and contracts with temperature swings.
- Coastal areas: Salt air accelerates wear on paint and on the metal fasteners underneath it, so look for products the manufacturer specifically rates for coastal or marine exposure.
Paint manufacturers list the conditions their product is rated for directly on the can or spec sheet, including minimum and maximum application temperatures and recoat times. Because these numbers vary by product and formula, always check the specific label rather than relying on a general rule of thumb.
Timing the job around the weather
Exterior paint needs a stretch of stable, mild weather to cure properly. Use this decision path:
- Check the temperature range on your paint label. Most exterior paints have both a minimum air temperature for application and a minimum surface temperature, and these can differ from each other.
- Check the forecast for the full dry time, not just the application day. Rain or heavy dew within the first several hours after painting can wash out or spot fresh paint. Your paint’s label will state the minimum dry time before it’s rain-safe.
- Avoid direct, intense afternoon sun on the surface you’re painting. Paint applied to a hot surface can dry too fast, leading to lap marks and poor adhesion. Many painters work the shaded side of the house in the morning and follow the shade around during the day.
- Avoid high humidity days. High humidity slows drying and can affect how the paint levels and cures, even if the temperature itself is in range.
- Build in a buffer. If your forecast shows a narrow dry window, wait for a longer one. A paint job that doesn’t fully cure before rain or a cold snap often needs to be redone.
What this project typically involves
Exact costs, timelines, and the number of coats needed depend on your home’s size, siding material, current paint condition, and local labor rates, so this guide won’t estimate numbers that vary by project. For a cost range specific to your home, get written quotes from at least two or three licensed, insured painting contractors, and ask each one to specify what surface prep is included in their bid. A low bid that skips scraping, priming, or caulking can cost more in the long run.
FAQ
Do I need a permit to paint the exterior of my house?
Most areas do not require a permit for straightforward repainting. Some historic districts, homeowners associations, or municipalities do regulate exterior colors or require notice for scaffolding or lift equipment. Check with your local building or planning department to confirm the rules for your address before starting.
How do I know if my house has lead paint?
If your home was built before 1978, assume lead-based paint may be present unless testing shows otherwise. A certified lead inspector or risk assessor can test your home, or you can use an EPA-recognized test kit. When in doubt, follow lead-safe practices or hire an EPA or state lead-safe certified firm.
Can I paint over slightly damp or recently washed siding?
No. Give washed surfaces time to dry fully, and never paint over wood that feels damp or a surface that rained on recently. Trapped moisture under a new coat is a common cause of early peeling and blistering.
What’s the difference between hiring a painter and doing it myself?
A licensed, insured contractor carries liability coverage, has training in lead-safe practices where required, and typically has the equipment for taller or steeper sections safely. DIY can work well for single-story homes in good condition without lead paint concerns, but height, structural damage, or pre-1978 construction are good reasons to bring in a professional.
Safety disclaimer
This article provides general educational information and is not a substitute for a site-specific inspection, a licensed contractor’s assessment, or your local building department’s requirements. Homes built before 1978 may contain lead-based paint; disturbing it without following EPA lead-safe work practices, or without hiring an EPA or state lead-safe certified firm, can create serious health hazards. Stop and consult a qualified professional for structural damage, suspected mold, electrical work near the work area, or any project involving heights beyond what a standard extension ladder safely allows. Review our full project safety disclaimer for more on when to bring in licensed help, and see our sources and methodology page for how we vet the guidance we publish. You can also learn more about our editorial standards and our editorial team.