Common Exterior House Paint Problems to Watch Out For

Not sure when to repaint your exterior? A quick inspection of your paint can give you the answer. Here are the 10 most common exterior house painting problems and how they can be fixed.

Blistering paint

Blistering is when small or medium-sized bubbles or voids form below the paint. This is most commonly seen on wood trim or on wood siding. This happens for a few reasons, either the paint was applied on too hot of a surface or it was put on wood that wasn’t completely dried. If water gets trapped under the paint you are going to get blistering.

How to solve it

The only way to deal with this issue is to scrape and sand away the areas that are blistering. The area should be sanded to bare wood and allowed to dry. Once you have a well-prepped surface that isn’t wet or hot you can then prime and paint to match.

Mildew

Mildew is a fungus that loves to grow in damp dark areas like under eaves and overhangs. It can also grow on any side of your house that gets no sunlight. It appears as a brownish-green film. If you attempt to paint over mildew it will just continue to grow. It also likes to grow on any bare exposed wood that may have lost paint due to peeling.

How to solve it

Mildew has to be removed via cleaning with water mixed with bleach or a trisodium phosphate cleaner. Water alone won’t kill it. It may not be necessary to power wash the mildew away. If it’s just a small area you may be able to apply the cleaning solution with a sponge and then wait a while before rinsing it off with a hose.

Paint runs, sags, and drips

This isn’t a paint problem so much as a paint application issue. When you see paint that appears to be sliding off the siding it’s caused by a few things. The first is that too much paint was applied, alternately the paint could have been thinned out too much. It can also be caused by the paint being applied to a surface that should have been primed or that wasn’t cleaned before the paint was applied.

How to solve it

If this happens while you are painting you can use a brush or roller to smooth out the paint and make it even. If you discover it after the paint has dried you can sand it smooth and repaint it. You may want to try applying two thin coats instead of one heavy one as well.

Checking, crazing, and “alligatoring”

This is a pattern that forms on dried paint and looks like little squares, cracks, or alligator skin. It forms on paint jobs that have been completed with more than one coat normally. It can lead to paint chipping and pealing if left unaddressed. This can appear when the second coat of paint is applied before the first coat has had time to dry. It can also happen when the second coat is made of paint dramatically different from the first coat. Any oil-based paint is susceptible to this and painting high gloss paint over latex can cause it as well.

How to solve it

No good news for this problem, the fix requires sanding, priming, and repainting with a flexible latex paint. Never mix different finishes of paint and always use high-quality paint to avoid this.

Chalking

Chalking looks like a chalky powder covering the exterior paint. Although some chalking is normal, it can become a problem, especially in dry climates. Chalking can be a sign that the paint pigment is being released and the binders have broken down due to environmental factors. This is often caused by using cheap paint with pigment extenders, using interior paint on the exterior, or by using overly thin paint.

How to solve it

Power wash or scrub the area with trisodium phosphate mixed with water, then rinse with clean water. Once it is dry, you can paint over it with high-quality latex house paint.

Rusting paint

If you see red or brown stains or streaks forming on the surface of your paint it is likely caused by metal beneath the paint. Nails without corrosion resistance or galvanized nails that have lost their galvanized coating on the nail head can cause this.

How to solve it

Find the nails and remove them, then replace them with stainless steel or galvanized nails. If they cannot be removed, sand the head to bare metal and countersink them with a nail punch. Caulk or fill the nail heads and sand the area smooth, use a primer with a stain-blocking and rust inhibiting factor and then paint over the area.

Peeling paint

This is a common issue that comes from moisture or poor adhesion. The difference is that paint is peeling from a previous layer versus peeling from the surface material itself. This can occur when the surface is wet, dirty, or too smooth for adherence.

How to solve it

Unfortunately, you have to remove the entire layer till you get to a dry layer that has a surface with enough hold to paint on.  You have to scrape the peeling paint and sand the affected area.

Efflorescence

Efflorescence is found in painted masonry. It looks like white salty deposits coming through the paint. This is caused when the brick or masonry isn’t prepared before painting. Moisture tends to pass easily through concrete, brick, masonry, and stone. Because of this, a waterproof primer layer is required to prevent groundwater penetration.

How to solve it

First, you must find the source of the water that is affecting your wall. Patching and caulking the source will prevent a reoccurrence. Next, remove all signs of the efflorescence and wire brush any flaking or chalky paint. Clean the area with a trisodium phosphate solution and rinse clean. Wait for the area to completely dry. Then, use a waterproof primer and paint with latex house paint.

Foaming and Cratering paint

This is an exterior house painting problem that can be dealt with at the time of painting. It shows as depressions or impressions in the paint film when it dries. It is caused by using paint that is frothy with air bubbles. Air can get into the paint if it was just shaken, it can also occur if the pint was applied too quickly with a roller or brush.

How to solve it

All paints will bubble to a certain extent. Higher quality paints are made so that the bubbles will break before drying and create a flat surface. Avoid rolling or brushing too much or too quickly and also consider using a shorter nap roller.

Burnished paint

A change in the gloss of your paint when it is rubbed, scrubbed, or brushed against. It happens when a “shiny” spot appears from being repeatedly rubbed against. Low-grade paint will form burnished spots quicker than quality paint. If you have furniture, a washing machine, or anything else constantly rubbing against the same spot you will get burnishing.

How to solve it

Aside from using higher grade paint, which you need to start with, anywhere that will be subject to regular cleaning or have repeated rubbing from the furniture should be painted with a premium semi-gloss or gloss acrylic enamel. The gloss will help protect the paint from rubbing. Always make sure that when you clean it, you use a non-abrasive cleaner.

If your house is showing signs of problem paint why not let the pros at CertaPro of Rochester Hills give you a free estimate on your next house painting project. Why wait till the little problems become big ones!