There are more typical exterior paint problems that need to be spotted and solved. See part 1 to learn about what is commonly seen in outdoor paint problems.
Paint Peeling Caused by Interior Moisture
Interior moisture is the last cause of peeling paint, and it is characterized by cracking and soft peeling away of the paint from the substrate as it loses adhesion owing to the moisture. This form of paint failure might be caused by moisture originating behind the paint film or frontal moisture forcing its way through the paint film.
Possible Root Causes
Humidity has permeated the paint coat in high humidity areas such as bathrooms, kitchens, hot tubs, and moist basements.
Water has seeped into the house through leaking flashing around a chimney or other exterior wall/roof intersection, wetting the plaster from beneath the paint film, and causing the paint to detach from the substrate.
Repair and Maintenance
In places with a lot of moisture, like bathrooms, install an exhaust fan that pulls out the moisture and sends it outside.
Ensure that the roof, walls, and soffits are well-ventilated.
Replace any missing or broken flashing around the chimney or any wall or roof connections.
Remove old, flaking paint and feather-sand the problematic areas. Locate a prime, bare area. Use high-quality acrylic latex paint to paint.
Discoloration Caused by Rust
Rust-colored, reddish-brown to black spots on a painted surface characterize this issue.
Possible Root Causes
Instead of galvanized zinc-plated, or stainless steel nails, non-corrosion-resistant nails were used to attach to the siding.
Steel nails have been exposed to the elements.
Steel nails have emerged from beneath the surface.
The galvanized coating on the nail heads is gone because they have been weathered or ground too much.
The tannic acid from moist wood (such as oak) has interacted with steel nails to form a black stain.
Repair and Maintenance
If possible, replace steel nails with stainless steel or galvanized nails.
If rusty nails cannot be removed, rust can be eliminated by sanding nail heads to bare metal and countersinking them. Then, prime with a rust-inhibiting, stain-blocking primer. Caulk, fill, or patch sunken nail heads with high-quality paint, then sand smooth.
Running or Sagging
When you see layers of peeling, worn, and sagging paint. A paint film with a droopy, dripping appearance clearly identifies this paint failure.
Possible Root Causes
A coat of paint was applied in an excessively heavy or overloaded manner.
When applying the paint, it was overly thinned.
The paint was applied in unfavorable weather conditions, such as when temperatures were too low or humidity levels were too high.
The paint was applied to a high-gloss surface that had not been prepped previously. This takes away from the paint substrate the tooth that is needed for the top coat to stick.
At the time of application, the painted surface was not clean or properly prepared.
Repair and Maintenance
If you notice the drooping when the paint is still wet, spread the surplus paint evenly using a brush or roller.
If the paint has dried, sand the uneven region and reapply the paint sparingly.
If the paint was applied on a shiny surface, sand it to dull it and produce an area for the paint to stick, or use a primer and repaint.
Paint with two light coats rather than one heavy one.
Make sure not to overwork the paintbrush. Use a paintbrush in the correct manner.
Paint Peeling Due to Poor Adhesion
Peeling paint is a typical paint issue that can be caused by moisture or a lack of adherence. Peeling caused by inadequate adhesion is distinguished by the paint peeling. Separating from a previous paint layer (intercoat peeling) or from the substrate, leaving some paint behind. Under the curling, peeling paint layer, parts of previous paint layers are sometimes apparent.
Possible Root Causes
The paint was placed on a dirty, moist, or shiny surface with poor paint surface preparation.
Prior to being repainted, the underlying paint had poor adherence.
A moist surface was painted with oil-based paint.
The blistering paint was allowed to dry. Blisters will eventually rupture and peel.
The paint was of poor quality.
Repair and Maintenance
Remove old, flaking paint and feather sand the problematic areas.
Locate a prime, bare area.
Caulk as needed using the proper caulking product.
Repaint with an acrylic latex home paint of a good grade.
Mildew
Mildew is a common fungus that feeds and grows on paint film or caulk and is distinguished by splotchy gray, brown, green, or dark black spots.
Possible Root Causes
Moisture, poor ventilation, and a lack of direct sunshine have all contributed to the growth of fungus. Mildew thrives on the undersides of soffits and eaves.
The paint was put over a mildewed surface or former paint film.
A lower-quality paint was utilized, with little mildewcide.
Before painting, the bare wood was not prepped.
Repair and Maintenance
Scrub hard with a cleaning solution made of trisodium phosphate or a solution of 1 part bleach to 3 parts water that you made at home. Wear goggles and rubber gloves.
Allow 10 to 15 minutes for the solution to settle on the cleansed area.
Rinse well with clean water.
Wash and rinse the area with a detergent solution.
Allow to completely dry before applying high-quality latex house paint.
Paint Peeling Due to Exterior Moisture
The big peeling pieces that expose bare wood beneath separate moisture peeling from other sources. Unlike peeling caused by adhesion issues, which can be patchy, moisture-related peeling produces considerably greater sections to peel away, frequently near windows, doors, and gutters.
Possible Root Causes
Moisture has gotten beneath the paint coat because of faulty or missing caulk. Leaks in the roof or wall systems or being too close to the ground could also create moisture problems.
Ice dams or water backups have been caused by faulty guttering or a lack of ventilation.
When the paint was applied to a wet surface caused by condensation or rain.
Repair and Maintenance
Ensure that gutters and downspouts are properly draining away from the house.
To get rid of the source of moisture, put in exhaust fans, soffit vents, siding vents, louvers, fans, or dehumidifiers.
Replace any missing or damaged caulk.
Remove old, flaking paint and feather-sand the problematic areas. Locate a prime, bare area. Caulk as needed using the proper caulking product. Repaint with an acrylic latex home paint of a good grade.
Read part 1 for other ways to identify and correct commonly found exterior paint problems.