Paint Failures...

The Guide | Introduction | Paint Failures | Surface Preparation | Surfaces | Caulk
Primers and Paints | Stains | Maintenance | Colour | Painting Pointers

Understanding the primary causes of paint failures will help a homeowner prevent future paint problems. The primary causes of paint failures are moisture, inadequate surface prep, the improper application of paints, the Sun, and weathering. Homeowners should be aware that most paint failures are related to moisture and inadequate surface preparation. Please refer to the Surfaces section for more information concerning surfaces and surface preparation. Some of the more common paint failures are listed below in alphabetical order with recommendations for their prevention.

Alligatoring is cracked paint that resembles alligator skin, and is generally found on wood surfaces. Alligatoring occurs when paint can not adhere to a glossy surface, when a second coat of paint is applied over an inadequately dried first coat of paint, weather aging, excessive coats of paint, or when the finish coat expands and contracts at a greater extent that any underlying coats. Paint must be completely removed when alligatoring has occurred to ensure an even and uniform finish. Wood surfaces should be primed with a top quality alkyd primer and acrylic latex finish.

Bleeding is an unsightly surface discolouration commonly found on exterior wood surfaces and hardboard siding, ceilings, repainted wallpaper, or when light coloured paint is applied over dark coloured paint. The causes of bleeding are moisture and water soluble dyes located within wood surfaces and wallpaper, and inadequate priming of surfaces. Bleeding on hardboard siding is caused by wax. The removal of any excessive water source is essential before any surface preparation can be completed. Exterior wood surfaces should be primed with top quality alkyd based primers and finished with top quality acrylic latex paints. Interior surfaces should be primed with either a top quality alkyd based or acrylic latex based stain blocking primer, and finished with a top quality acrylic latex finish paint.

Fresh paint applied in direct sunlight, and moisture, causes paint to blister. Surfaces that are heated by the Sun and become hot can prematurely dry new paint, causing blistering. This is more common with dark or dramatic colours because they, in addition to surfaces, absorb heat. Heat blistering will have a layer of paint under the blister if the surface is being repainted. Trapped moisture in walls or behind surfaces will eventually try to escape through painted surfaces, also causing blistering. Moisture blistering will reveal a bare surface under the blister. Blistering surfaces should be scraped and sanded smooth, primed with a top quality alkyd or acrylic latex primer, and finished with a top quality acrylic latex finish paint. If moisture blistering occurs on a repainted surface, spot priming of bare spots will be necessary to ensure a uniform and even finish before the final priming and painting is completed.

Chalking is the weathered powder found on exterior painted surfaces and is a normal way for paint to weather away. However, premature chalking can be caused by inadequate priming or thin paint. Homeowners should be aware that chalking on siding located above masonry will run during rainy weather causing the masonry to stain. Once a chalked surfaced is pressured washed clean and prepared for painting, one coat of a top quality alkyd primer and one coat of a top quality acrylic latex finish paint is highly recommended for the prevention of future excess chalking.

Checking and Cracking
Checking is an early form of cracking and occurs when paint begins to loose elasticity, forming narrow breaks on the painted surface. These breaks later swell and become cracks. Checking and cracking are found on wood surfaces with multiple layers of paint, or plywood. Checked or cracked paint should be completely removed from surfaces before repainting. Properly prepared wood surfaces should be primed with a top quality alkyd primer and finished with a top quality acrylic latex finish paint.

Efflorescence is a white salty substance that forms on masonry and plaster due to moisture migrating through the surface. If left untreated for long periods of time, it will become hard and crusty. Any source of excessive moisture must be eliminated and the surface must be cleaned by scraping or wire brushing, and surfaces must be repaired where applicable before priming and painting. Surfaces can be painted with top quality alkyd or acrylic latex based primers and paints that are alkaline resistant.

Fading is caused by the natural weathering due to the ultraviolet rays of the Sun. Chalking pigment, alkali from masonry, and tint intended for interior based paints but used on exterior surfaces, will cause paint to fade prematurely.

Hatbanding is caused by the over cutting in of interior walls, ceilings , and trim corners, and the use of excessively long roller naps. It occurs when wet paint is applied over dry paint. Hatbanding is very noticeable with dark and dramatic interior colours and sheens. Using small nap rollers and applying a thin brush coat of paint will help eliminate hatbanding.

Lap Marks
Lap marks are due to the inadequate application of coatings. They are mostly seen on exterior surfaces. If a homeowner or contractor is brush painting siding, the paint must be applied horizontally from one end to the other without stopping. If the homeowner or contractor stops in the middle or the paint dries to fast, when the application of the paint to the surface is continued, a lap mark forms where the paint overlapped. This is a major reason why coatings should never be applied in direct sunlight. Coatings should be applied in shady area's in warm months and homeowners and contractors should stay ahead of the Sun in cooler months. Staying ahead of the Sun will allow it to come around and dry the area most recently painted.

Mildew is a fungus that grows best in a warm humid climate and is often found in shaded area’s, but not limited to shaded area’s. Mildew can appear in a variety of colours and prefers painted surfaces because of the nutrients that paints provide. These same nutrients float through the air and land on painted surfaces and become food. Mildew grows faster on flat surfaces than on glossy surfaces, and is attracted to linseed oil based products that contain no mildewcide. Most paints and stains come already made with mildewcide included. However, mildewcide can be added to paints and stains that do not contain one. Mildew can be effectively cleaned with a 3 to 1 ratio of water to bleach. A much stronger solution maybe necessary in extreme cases of neglect. Proper surface preparation and cleaning are crucial for mildew prevention, in addition to using a top quality primer and acrylic latex finish paint. Acrylic latex finish paints are the most mildew resistant. Painting contractors who perform quality surface preparation and painting are a homeowners best ally in preventing the growth of mildew.

Peeling occurs on a variety of surfaces and is directly linked to moisture and inadequate surface preparation. Understanding different surfaces and how they react to moisture and coatings will greatly reduce the risk of this common paint problem.

Rusting occurs when metal is exposed to moisture and oxygen. Any metal surfaces should be completely sealed with a rust inhibited primer. If rust appears through painted surfaces, it should be wire brushed to bare metal, or treated with a coating that will harden it. Two coats of a top quality rust inhibited alkyd or acrylic latex primer should be applied to metal surfaces once the rust is treated or wire brushed away. Rusty nails that bleed through surfaces should be reset, coated with a top quality rust inhibited primer, caulked, primed, and painted with top quality coatings.

Sagging and Running
Sagging and Running can occur when paint is applied over glossy surfaces, excessive thinning, too much paint, or paint being applied to a dirty surface. Proper application of paints and surface preparation will eliminate sags and runs.

Wrinkling is caused when thick paint is not brushed out and the under part remains wet, but the surface layer dries. Avoid covering surfaces with one thick coat when two are required.