Brush-n-Roll vs. Spray – Exterior
Customers ask me all the time about which application method my painters are going to use to apply the primers and paints. It seems these customers have a bias against spraying and want to ensure that we are not going to spray the coatings on. For many customers, spraying is the inferior application method.
This is not necessarily so. The goal when applying coatings is to get a smooth, even thickness of the paint film on all areas. An experienced spray applicator can achieve a superior coating than an average brush-and-roll guy, and vice versa. In fact, it is often harder to get an even, uniform paint film using a roller than a sprayer. As the roller is dipped, comes out of the bucket, and is rolled in the wall, the area the roller is first applied to receives a thicker coat than the areas covered as the roller is rolled farther along. Usually, the painter will then roll back into the areas with the thicker coating to even out the paint on the wall, but it is very hard to ensure that the coating is even in all areas.
On the other hand, the spray that comes out of a spray rig is applied at the same rate to all surfaces, when applied correctly. Factors that may change the thickness of the paint film when spraying are 1) differences is speed applied (speeding up or slowing down the path of the spray gun will result in a thinner or thinker coat), and 2) variances in the distance from the surface being coated (closer to the surface will result in a narrower but thicker coat, and vice versa).
An experienced spray applicator will keep the speed and distance of the gun from the wall even, resulting in a smooth, uniform coat of paint. Moreover, the correct way to spray is to overlap passes of the gun by 35-50% on each pass, and then apply a second coat perpendicular to the first coat, creating a cross-hatched pattern that goes even further to ensure a smooth, even finish.
Alternatively, there is a method my company and a few others often use called a “spray with a back roll/brush”. In this method, a spray rig is used to get the paint from the bucket onto the wall in the most efficient manner – less labor because there is no dipping of a roller, and the coverage is fairly uniform. Right behind the sprayer, though, is a painter who is rolling and/or brushing the wet paint out. This provides the best of both worlds: efficient and even application of the paint material onto the wall with the sprayer, and assurance that all cracks, gaps, and crevices receive the proper coating via the pressure of a brush or roller.
In sum, the different application methods are not indicative of quality in and of themselves – the quality of the finish is going to be determined by the skill of the painter using the tools of his choice. Application method is something you should discuss with your estimator or contractor as part of the estimation appointment and understand why s/he proposes to do it the way s/he does.