Painting the exterior of your home can completely transform its curb appeal and protect it from the elements. However, unpredictable weather can put a damper on your painting plans. While painting in rainy conditions is not ideal, with proper planning and preparation, you can successfully paint the exterior of your house even when the forecast calls for showers.
Why Rain Can Be Problematic for Exterior Painting Projects
Painting during rainy weather comes with a unique set of challenges:
- Moisture – Excess moisture can prevent paint from properly adhering to the surface. It can also cause bubbling, cracking, peeling and other paint defects down the line.
- Mildew and Mold Growth – Wet conditions promote mildew and mold growth, which can quickly damage freshly painted surfaces.
- Long Dry Times – Humid, wet weather slows down paint’s drying time. Quick-drying paints can take up to twice as long to fully cure in rainy conditions. Slow dry times increase the risk of damage to the paint.
- Poor Coverage – Rain can wash away fresh paint, affecting coverage and color uniformity. It may take extra coats to achieve full coverage.
- Debris – Wind driven rain can blow leaves, dirt and other debris onto freshly painted surfaces, resulting in a disappointing finished look.
If possible, it’s best to plan outdoor painting projects during dry weather. However, with the right prep work and products, you can successfully paint in rainy conditions when scheduling conflicts leave you no other choice.
Tips for Painting in the Rain
Follow these tips to get professional quality results when painting exteriors in wet weather:
Choose the Right Time
- Check forecasts closely – Pick days with only light showers in the forecast rather than steady rain or thunderstorms. Be prepared to stop work and cover surfaces when heavier rain hits.
- Paint in the morning – Plan to get the bulk of painting done in the morning, before any rain showers typically start. Morning dew should also be dried up.
- Watch temperatures – Ideal temps are 50-90°F. Avoid painting on extremely cold, hot, or humid days.
Use Suitable Products
- Choose quick-drying paint – Look for paints labeled “fast-drying” on the can. Avoid regular and oil-based paints with slower dry times.
- Use primers – Priming creates a uniform surface for topcoats to adhere to. It’s especially important for painting in damp conditions.
- Apply specialty additives – Additives like anti-mildew ingredients and extender primers help paint adhere and spread better in wet weather.
- Use higher sheen paints – Gloss and satin finishes withstand moisture better than flat or matte paints.
Prep Surfaces for Wet Conditions
- Clean thoroughly – Use a pressure washer to remove mold, mildew, dirt and other contaminants from exterior surfaces before priming and painting.
- Fill cracks and holes – Water can seep into openings, so thoroughly seal cracks, seams, and holes with caulk.
- Remove glossy finishes – For best adhesion, scuff up any existing glossy paints with sandpaper.
- Replace rotted boards – Swap out any exterior boards that are rotted or warped. Paint won’t properly adhere to damaged wood.
Maintain Ideal Painting Conditions
- Work in covered areas – When possible, paint sections of the home shielded by overhangs and protected areas first.
- Use tarps and tents – Cover scaffolding and exterior walls with plastic tarps for temporary protection from the elements.
- Control humidity – Use dehumidifiers and fans to lower humidity levels on the painting surface area.
- Apply painter’s tape – Tape around windows, trim and other surfaces you don’t want painted. Remove tape as soon as the section is painted before rain can seep underneath.
Monitor and Maintain Fresh Paint
- Check forecasts – Be prepared to stop work and cover freshly painted areas if heavier rain than expected moves in.
- Allow proper recoat times – Applying coats too soon traps moisture and affects curing. Follow manufacturer guidelines closely.
- Inspect for damage – Check painted surfaces once they are dry for blistering, peeling and washout that may need touch-ups.
What Type of Paint to Use in Rainy Conditions
Choosing a high quality, fast-drying paint designed for wet applications is key to success when painting in the rain. Here are the best options:
Latex Paint
Latex-based acrylic paints are ideal for exterior painting in rainy weather for several reasons:
- Dry significantly faster than oil-based paints, usually within 1-2 hours
- Resist moisture damage such as blistering and cracking
- Provide good coverage that lasts for years
- Available in satin and gloss sheens that resist moisture well
- Offer excellent adhesion and permeability for damp surfaces
- Can be thinned with water for easier application in high humidity
Primer-Sealers
Combination primers and sealers offer great benefits for painting in wet weather:
- Form a water-resistant film that protects topcoats
- Seal porous surfaces like wood, stucco and masonry
- Prevent moisture penetration into the substrate
- Block stains from bleeding through paint
- Allow for same day top-coating in many cases
Oil-based primers work well for sealing exterior substrates before painting in rainy conditions. Latex primers are another fast-drying option, although they may require 24 hours before applying finish coats.
Elastomeric Paint
If your exterior walls will be subjected to frequent rainfall after painting, consider an elastomeric coating:
- Offers unmatched flexibility and water resistance
- Bridges minor exterior wall cracks and gaps
- Expands and contracts without cracking or peeling
- Resists wind driven rain exceptionally well
Elastomeric coatings are ideal for surfaces with existing paint damage since they adhere so well to compromised areas. They come in various sheens from flat to high gloss.
Masonry Paint
For painting exterior concrete, stucco, brick and other masonry in wet weather, use a high quality masonry paint:
- Contains acrylic resins that form a durable, moisture-resistant finish
- Offers superior adhesion and hiding power on porous masonry
- Resists alkali and efflorescence that can form on exterior masonry
- Can be used on masonry with a pH of up to 13 without bubbling or peeling
- Provides long-lasting protection from rain and wind on exterior walls
For damp masonry, look for masonry paints formulated for wet surface application.
Mildew Resistant Paint
Paint containing EPA registered mildewcides helps prevent ugly black mildew stains from forming on exterior painted surfaces exposed to frequent rain:
- Added mildewcides inhibit the growth of surface mold and mildew
- Mildew-resistant properties last for several years
- Can be used on damp surfaces prone to mildew growth
- Ideal for exterior siding, eaves, trim, decks, fences and other areas exposed to rain
- Helps exterior paint last longer and look freshly applied for years
Mildew resistant additives are commonly found in today’s exterior latex and acrylic paints. Look for “mildew resistant” clearly labeled on the paint can.
Fast Dry Paints and Additives
For the fastest dry times when painting in wet weather, look for:
- Fast dry paints – Shortens drying time by 50% or more compared to conventional exterior paints.
- Quick-dry primers – Offer faster drying basecoats; some can be topcoated within an hour.
- Paint accelerator additives – Mixed into paint, these dramatically speed up drying time in damp conditions.
Using fast-drying paint products eliminates extended downtime waiting for coats to dry between showers.
Low Temperature Paint
Exterior paint specially formulated to cure properly in cooler temperatures can also be a good choice for rainy weather painting. Features include:
- Ability to form a durable paint film and cure fully in temperatures as low as 35°F
- Resists blistering, cracking and peeling when applied in cool, damp conditions
- Ideal when overnight temperatures may dip down and inhibit drying
- Great for exterior painting during rainy seasons like spring and fall
This type of paint eliminates having to worry about overnight temperatures affecting curing of exterior paint.
Prep Work for Painting in the Rain
Proper prep work before painting in rainy conditions gives paint the best chance of coming out looking great. Key prep steps include:
Cleaning
- Use a pressure washer set to under 1000 psi to thoroughly clean exterior walls, siding, eaves, decks and trim. This removes mold, mildew, dirt and other contaminants that can prevent proper paint adhesion.
- For moldy areas, apply a mildew remover/cleaner first before pressure washing. Rinse thoroughly.
- Allow all washed surfaces to fully dry for at least 24 hours before priming and painting.
Repairing Damaged Areas
- Inspect all exterior surfaces and repair issues before painting. This includes filling cracks and holes, replacing damaged boards, fixing drips and flashing issues.
- Caulk around windows, doors, trim, corners and joints using a high quality, exterior-rated caulk. Smooth the caulk bead with a wet finger for a neat appearance. Allow caulk to fully cure before painting.
- Use wood filler, wood epoxy or Bondo as needed to patch holes, gouges and damaged areas on exterior wood before priming and painting.
Removing Glossy Finishes
- For painting over existing exterior paint or clear finishes that are glossy, scuff sand using 80-100 grit sandpaper to rough up the surface. This improves paint adhesion.
- Wipe or pressure wash away all sanding dust afterwards before applying primer and new paint.
Priming Bare Wood and Masonry
- Prime surfaces not previously coated with paint using an exterior primer ideal for the substrate. For example, use wood primer on exterior boards and trim, masonry primer on stucco and concrete, etc.
- Oil-based primers form the best moisture barrier on bare exterior surfaces. However, fast-drying latex primers also work well.
- Allow primers to dry fully before applying finish paint coats.
How to Paint Exteriors in Rainy Weather
When the weather forecast calls for showers, follow these tips for a successful exterior paint job:
On Dry Days
- Take advantage of any dry days or stretches of a few hours without rain to do as much painting as possible. This minimizes the amount of time paint will be exposed to moisture.
- Focus first on painting trim, fascia, eaves, railings, shutters and other narrow surfaces. They are most vulnerable to washout from rain.
- Use drop cloths underneath exterior painting areas to protect plants and surfaces from drips. Ideally use cloth tarps rather than plastic to allow airflow and drying.
Applying Primer
- Prime early in the day when temperature is warm and surfaces are dry to allow maximum drying time. This is especially key for bare wood and masonry.
- If priming bare surfaces like new wood siding or trim, apply two coats of primer for maximum water protection. Lightly sand the first coat before applying the second.
- When priming previously painted surfaces, one coat of primer may suffice if the old coating is still in good condition.
Paint Strategically
- Paint sections of the home’s exterior shielded from rain first, such as covered front porches, under eaves and overhangs. This allows more time for curing without exposure to moisture.
- When possible, start painting on the side of the house opposite the weather forecast’s wind direction so fresh paint isn’t blown onto while still wet.
- Use brushes to cut-in around windows, doors, trim, corners and other tight areas first, then quickly roll larger exterior walls before rain starts.
- Follow the sun as you paint, moving into shaded areas as sunlight shifts across the exterior throughout the day.
- If needed, erect temporary tarps secured tightly to scaffolding or ladders to provide cover as you paint exterior walls most exposed to precipitation.
Applying Finish Coats
- When topcoating primed surfaces, watch that primer is fully dry first to avoid trapping moisture underneath the final paint layer.
- If primer dried overnight, look for any glossy areas that may still be tacky and spot prime them again before final painting.
- Apply finish coats using a high quality roller sleeve designed for smooth, uniform application like microfiber or woven polyester nap.
- Backroll over each section as you paint to even out paint and avoid lap marks. Maintain a wet edge as you paint.
- Paint until rain forces you to stop work. Avoid mid-wall breaks that can leave overlap marks.
Avoiding Runs and Drips
- Don’t over brush paint when cutting-in. Pulling too much paint out of trim corners risks drips. Instead, brush paint thinly and evenly into corners.
- Apply paint generously to exterior siding using a fully loaded roller. Then immediately backroll to evenly distribute paint and avoid runs.
- Paint top to bottom on exterior walls to avoid drips running through freshly painted lower areas.
- Use artist style brush guards when painting trim and corners to catch stray drips as you work.
Drying and Recoating
- Allow paint adequate drying time between coats per manufacturer recommendations, longer than normal due to humidity. Thick films take longer to dry.
- Test paint dryness by pressing firmly on the paint film with your finger. Any indentation left means it’s not fully cured yet.
- When possible, use fans and portable dehumidifiers to speed overall drying times if raining. Just keep fans far back to avoid blowing dust onto paint.
- If overnight low temperatures are a concern, setup floodlights to gently warm the exterior overnight. Never use direct heat on paint.
Cleaning Up
- When done painting for the day or before rain starts, protect freshly painted surfaces by lowering scaffolding tarps or covering with plastic drop cloths carefully secured on top.
- Clean brushes and other painting tools well before paint has a chance to dry. Use mineral spirits or water depending on the type of paint.
- Check weather again and setup tarps over any areas that may get hit with wind driven rain overnight. Secure tarps tightly.
- If paint gets wet before drying, don’t attempt to wipe it off. Let it fully cure first, then inspect for any damage needing touch up.
After Rain: Inspecting Paint and Making Repairs
Once paint has fully cured following wet weather application, inspect all surfaces closely looking for any defects needing touch up:
Check for Drips
Closely inspect the bottoms of exterior walls, trim, posts, doors and railings for any rain-caused drips. Use a small artist’s brush to feather out minor drips and sags so they blend seamlessly into the surrounding finish.
Inspect for Blistering
If exterior paint blistered due to moisture being trapped under the surface, sand down any raised blisters before spot painting. Use 100-150 grit sandpaper for a smooth surface. Wipe away all sanding dust before touch up painting.
Fix Peeling or Flaking
Check areas vulnerable to moisture like bare wood siding for any spots of peeled or flaking paint. Scrape away all loose paint, feathering the edges. Wipe cleaned areas with a tack cloth before priming and painting.
Repair Washouts
If rain washed off sections of uncured paint, sand any remaining loose paint around the edges to create a smooth surface. Spot prime if bare substrate is exposed before painting. Blend repaired sections into surrounding areas.
Touch Up Mistakes
Carefully work fixable mistakes like errant drips, splatters, brush marks and any other imperfections using the same paint as originally applied. Precision artist’s brushes help best blend touch ups.
Apply Clear Coat (if desired)
For added water repellency and to help paint better withstand frequent rain exposure, apply a clear sealer / topcoat after paint has fully cured. This adds an extra layer of durable protection.
Maintaining Exterior Paint in Wet Weather Climates
To help freshly painted exteriors maintain their beauty over the long term despite regular exposure to rain, follow these key maintenance tips:
- Inspect painted exterior surfaces twice per year, in spring and fall. Look for any paint damage or wear to address.
- Re-caulk around windows, doors, trim and fixtures annually before wet winter weather hits. Check flashings and exterior seals too.
- Consider applying a fresh coat of clear sealer/topcoat every 2-3 years for added water repellency and protection.
- Control mold and mildew growth by cleaning exterior painted surfaces annually with bleach or mildewcide solution.
- Trim back branches, bushes and vegetation touching exterior walls to allow proper air circulation and drying during rainy periods.
- Fix roof leaks, gutter issues and other moisture sources immediately to avoid paint blistering and peeling.
- Repaint exterior surfaces on a regular repainting schedule, usually every 4-8 years depending on paint quality and exposure levels.
Troubleshooting Common Paint Problems During Rainy Weather Painting
Even when taking all the right precautions, issues can occasionally still pop up when painting exteriors under wet conditions. Here are solutions for common rain-related paint problems:
Problem: Finish coat took on a hazy, dull appearance
Solution: Wet conditions caused low sheen paint to lose its luster as it dried. Recoat with another finish coat to restore uniform appearance.
Problem: Paint is slow to dry and feels sticky
Solution: Humidity and low temperatures are likely factors. Use fans, dehumidifiers and floodlights (carefully) to speed drying time.
Problem: New paint is streaky, uneven and blotchy
Solution: Too much moisture wicked into