Differences in Metal Roof Paints

Manufactured Roof Paints

• Metal roofing manufacturers offer three main types of paint. Acrylic emulsions are the greenest, most environmentally compatible paints as they contain the least amount of chemicals. Roofs using acrylics require a primer and a top coat and are prone to chalking and fading. Polyesters are less environmentally friendly, but generally lower in cost than acrylics. They also fade and develop chalky finishes over time. Fluoropolymer paint is the most costly option, but it lasts a long time, is resistant to airborne solvents and acids, and has a slick, non-stick finish that is fade and chalk resistant.

Consumer Roof Paints

• Two types of available metal roof paints are available to homeowners doing their own work. Acrylic metal roof paint has a water base and elastomeric properties that make it expand and contract during hot and cold weather. This flexibility deters cracking. Some types require primers, and others can be directly applied to metal roofs. Oil-based metal roof paints are durable and don’t need primers. However, they usually have to be applied in multiple coats. The chemical substances in oil-based paint can't be penetrated by soap and water like acrylic paint. Mineral spirits are required to clean brushes and pans, and to remove oil-based paint spills and spatters on clothes and skin.

Metal Roof Preparation

• Regardless of the paint used, metal roofs must be properly prepared for the paint to adhere to the surface and properly dry. Plan the project during dry seasons with moderate temperatures. Humid climates inhibit the drying process, and the paint could be damaged by dirt, leaves or insects. Very cold weather will freeze the paint and high temperatures will make the paint run. The roof must be free of all debris and rusty spots before any new paint is applied. All of the old paint must be removed without damaging the underlying metal. Finally, treat the roof with an alkaline-based solution. Power wash the roof, then let it thoroughly dry before painting.

Application Options

• Most metal roof paints can be applied with sprayers, rollers or brushes. Painting a metal roof may seem like a simple job, but study the scope of the project and the inherent dangers before doing it yourself. A professional roofing contractor may be the best option.