HOW TO & ADVICE: HOME PAINTING PROJECTS

Whether you are a professional painting contractor or a homeowner, one of the most common

Lap marks appear as denser color or an increased gloss where wet and dry layers overlap during paint application. Keeping a “wet edge” is the key to avoiding lapping paint. While painting, you need to move quickly enough so the paint being applied can seamlessly flow in to the just-applied paint.

What Causes Lap Marks?

Lap marks while painting can occur for a variety of reasons, including:

Surfactant leaching, or the appearance of brown residue or streaks on interior and exterior painted surfaces, is a common problem that occurs when painting with water-based latex paint. Despite its name and appearance, surfactant leaching is an aesthetic concern, and not harmful to the paint nor the surface it is on.

Surfactants are necessary water-soluble ingredients of latex paint. When paint dries in dry, well-ventilated conditions, those surfactants slowly rise to the surface. However, when those surfactants are exposed to moisture or humidity in the air while drying, they rise too quickly to the paint surface and settle, resulting in wall and ceiling stains, or surfactant leaching.

Flaking paint occurs when cracked paint begins peeling off its original substrate. In its early stages, the problem appears as hairline cracks in the paint, but will worsen over time if the problem is not fixed, causing larger pieces of coatings to chip off.

Paint cracking on walls, ceilings, and exterior surfaces happens due to a variety of causes, one of the most common being poor preparation of a surface prior to painting. Painting over cracked paint is a bad idea; it is important to remove any flakes from the surface before repainting.

Why Does Paint Crack and Flake?

• Poor surface preparation, especially when the paint is applied to bare wood without priming, or to previously coated surfaces that show signs of cracking or flaking paint.
• Using low-quality paint, as it may have inadequate adhesion and/or flexibility.
• Spreading paint too thin during application.
• Paint becoming brittle with age, failing to expand and contract with temperature and humidity changes.

Note: A more uncommon version of paint cracking is mud cracking, which is when paint cracks when drying due to too-thick application or extremely dry painting conditions.

How to Fix Cracked or Flaking Paint