Paint With Confidence
Exterior Common Issues & Solutions
Text & image courtesy of the Rohm & Haas Paint Quality Institute
Lapping
Appearance of a denser color or increased gloss where wet and dry layers overlap during paint application.
Possible Cause
- Failure to maintain a “wet edge” when painting.
- Use of a low solids “economy” paint.
Solution
Maintain a wet edge by applying the paint quickly enough so the paint being applied can still flow in with the just-applied paint. For cut-in work, corners can be brushed immediately after a section has been rolled and the paint is still wet. It is also wise to work in manageable-size areas; plan for interruptions at a natural break, such as a window, door or corner. Using a top quality acrylic latex paint makes it easier to avoid lapping problems because higher solids (pigments and binder) content makes lapped areas less noticeable. If substrate is very porous, it may need a primer/sealer to prevent paint from drying too quickly and reducing wet edge time. Alkyd paints generally have superior wet edge properties.
