Each step in an exterior house painting project - from surface preparation to paint product choices to the application - affect durability and aesthetics for years to come.
We ask a lot of exterior paint to protect our homes against insects, sunlight, water, moisture, erosion, temperature, and normal wear-and-tear.
Here are some common exterior painting problems, what causes them, and how we can extend the life of our investment.
7 Exterior Paint Problems and Solutions
What is Alligatoring?
Alligatoring looks like wide, crisscrossing cracks in the paint layers which resemble the hide of an alligator.
It is caused by poor paint adhesion to the exterior surface.
- The surface temperature may have been too cold for the paint to stick to the coat beneath it.
- The base coat wasn't dry or was a glossy sheen.
- The paint products used were not compatible, such as a hard oil enamel (best used for front doors or trim) painted over a softer base.
What is Blistering Paint?
Bubbles under the surface of a paint coat are known as blistering, which can lead to cracks in the paint.
Moisture or heat are typically barriers to adhesion of the paint that causes blistering. Repair interior and exterior moisture issues before repainting.
- Painting on hot surfaces in direct sunlight.
- Painting over a damp or wet surface.
- Moisture migrating through an interior wall to the exterior.
Why is the Paint Cracking?
One or more exterior house painting layers that split over time, beginning as hairline cracks and eventually flaking off the surface.
Cracking is generally caused by temperature, humidity, low quality paint products, or poor surface preparation.
- Lower quality paint that lacks flexibility to handle shrinking and swelling due to the New England weather.
- Improperly prepared surfaces or painting over bare wood without priming.
- Paint coats spread too thin.
Why is the Paint Fading?
Fading (Photodegradation) occurs when exterior paint loses pigment - the part of paint that provides color.
Over time, all paint fades. Dark colors are usually more noticeable, but fading happens slowly and almost entirely due to the effects of the sun.
- Direct sunlight.
- Interior paint product used for exterior house painting.
- Low-quality exterior paint product loses its color faster.
What Causes Peeling Paint on the Exterior?
When a paint layer is peeling, it pulls away from the exterior, leaving bare patches of exposed wood or previous paint layers.
Peeling is commonly due to moisture issues that should be addressed before the exterior is repainted. Ensure your gutter system is working properly, there are no leaks in the roof, and repair gaps around windows and doors.
- Water or moisture seeping under one or more coats of paint.
- Painting a damp or wet surface.
What is Chalking?
Chalking looks like a fine powder or dust on the exterior surface.
Chalking occurs as the paint releases pigment. To some degree, all paint chalks due to weathering and wears normally over time. Use higher-quality acrylic coatings to help resist chalking.
- Long-term exposure to sunlight.
- Other elements of weather including moisture and pollution.
- Low-quality, highly pigmented paint product.
- Use of interior paint for an exterior house painting project.
- Spreading exterior coats of paint too thin.
Mildew and Exterior House Painting
Paint does not cause mildew. Mildew is a natural fungus. It appears as black, gray, green, or brown spots on any surface.
A wet, shady, unventilated area is prone to mildew.
- Poor ventilation.
- Lack of direct sunlight.
To remove existing mildew, wear proper protective gear and scrub the surface with a cleaning solution of 1-part liquid bleach and 3-parts water. Do not add detergents or ammonia to the bleach/water solution. Wait fifteen minutes and rinse thoroughly with plain water. Then let the surface dry completely. Use a top-quality paint product that contains agents that inhibit the growth of mildew.
Professional Exterior House Painting Services
Exterior house painting requires proper sanding, scraping, and timing between coats to help prevent these types of problems. Product selection and application are also crucial. Browse our house painting FAQs more details.
Leave it to the professionals at ProTEK Painters of Newton. We'll perform a thorough inspection and itemize recommended preparation, repairs, and paint product in a written proposal. Our guarantee: We're not done until you say we're done.