Brush & Roll Vs. Spray – Interior
Unlike the exterior of your home, the decision to use either the brush & roll or spray application method has little to do with coverage, but more to do with your aesthetic choice of the finish and the ease of setting up the areas to be painted.
The brush & roll application method leaves more texture on the painted surfaces than the spray method. Rollers leave what is called “stipple” on walls. A roller’s nap refers to the thickness of the material on the roller cover and common sizes include ¼”, 3/8”, ½”, ¾” and 1”. The thinker the nap, the heavier the stipple that is left on the walls. Some people like some stipple, others don’t. In areas that are repainted frequently, such as rental units, this stipple can build up, making the texture of on the wall appear much heavier.
Brushing walls is usually reserved for “cutting in” around electrical receptacles, windows and doorframes, along baseboards, and where walls meet ceilings (and vice versa). Brushing on walls is used when the walls are being rolled out, but not when they are being sprayed out. Sometimes, there will be visible differences to the texture of the paint where “cut in” areas have been brushed (they show as being smooth or with slight brush marks) and where the main body of the walls has been rolled (areas with stipple). This is often very minor and difficult to see, so it not a concern for most people.
A bigger problems with the brush & roll method is called “picture framing”. Areas that are “cut in” with a brush appear either lighter or darker than the areas that are rolled out. This is more of a problem when only one coat is applied and/or there is a significant color change being performed. Picture framing problems usually disappear with additional coats of paint.
Spraying out walls leaves a very smooth, even finish with no stipple. On trim, spraying leaves a look that is similar to a “factory finish”. On the other hand, brushing out trim leaves brush marks. Neither is better than the other – it is a personal choice as to which you like. Some people like the look of brush marks on the trim, as it shows the delicate handwork of the paint job. Others like the smooth, clean lines of a spray finish, especially on new construction or remodel projects because it gives a more contemporary or modern look.
A more limiting factor in the decision to use one method over the other has to do with how difficult it is to protect all the areas that are not to be painted. Spraying out ceilings, walls or trim results in a light mist of paint (or “overspray”) landing on all surfaces in the area to be painted. This means that all areas not to be painted must be tightly and securely protected. Rosin paper is commonly taped down on the floors. Plastic sheeting is taped over the windows. HVAC vents and other opening must be tightly covered. Furniture and belongings must be moved out of the space or very securely wrapped and taped. All this protection takes time and effort which you will be paying for.
Alternatively, the brush & roll method does not require the same amount of protection. Sure, floors, window glass, and personal belongings need to be protected, but they will not be exposed to the invasive floating mist that spraying creates. Drop cloths and plastic sheeting will usually suffice and is significantly easier to put in place and tear down.
I hope this helps clear up some of the misconceptions about, differences between, and reasons to use one application method over another.