Some jobs should not be sprayed alone, such as rough surfaces like render, block walls or Artex, because a mechanical action is required to work the paint in, and to avoid spray shadows (called holidays). Other surfaces such as floors, need the mechanical action to improve adhesion. You may be unable to spray because of high winds, or simply because the customer will not allow it.
An airless roller is generally cleaner than a classic hand roller because you don’t get the initial roller spray after you have coated it. The cover will tend to look dry compared to a hand roller, because the paint is either inside the cover, or on the surface being painted (spray roller). As the cover has a constant wetness, you will get a more uniform coat; this leads to paint savings that can be considerable on new plaster. Airless paint rollers, designed to support the high pressures of an airless pump, are a valuable accessory. Beware of such pressure rollers who’s maximum working pressure is less than the maximum of the pump; these can are designed for low pressure pumps and can be dangerous if they become blocked by dirt in the paint.
By feeding a paint roller from an airless pump, you can save the time required to coat a hand roller, which studies have shown is about 50% of the total rolling time. The airless pump that feeds it can be located at some distance from where you are rolling, so if you are working from scaffolding or a platform, you can save time by having the pump with the paint on the ground and not having to fetch paint so often, as well as eliminating the risk of the paint bucket being blown off, or knocked off the platform. The pump can also be placed in a secure location with just the paint hose coming out from under the door. Experience has shown that a 9" wide power roller is wide enough for most jobs, as you do not need the extra roller width to carry more paint. Most power rollers have 9" heads although 12" and even 18" widths are available, as well as 3" heads for narrow work.
There are two types of airless rollers, the most common is internally fed with the paint distributed inside the roller cover which is perforated, the other is externally fed with the paint sprayed on the surface just in front of the cover (spray roller).
Internally fed paint rollers
There are several models available. Things to look out for: The paint should be delivered evenly right across the cover without drips from the ends. The end seals should keep the paint out of the bearing surfaces which would otherwise wear fast. The mechanism should be easy to clean and the roller pole robust enough to support the load from the painter bearing down on it. Spare perforated roller covers should be readily available at reasonable cost. As they need to fit the American standard roller head, they will have to be slightly smaller in diameter: 1" instead of our 1". Perforated covers with a foam layer between the nap and the core are available for rough walls and allow the cover to be kept very wet.
Spray Rollers
This type of roller is much faster than an internally-fed roller, because the work of spreading the paint is done by the spray head, which is directed onto the surface just in front of the roller cover that finishes the job of working in the paint, or providing the roller stipple finish.
A spray roller can be used to either roll, or spray, or both without stopping: since the spray head is directed in front of the roller, lifting it off the surface will allow the spray to pass underneath and spray without rolling. This is invaluable for painting surfaces that cannot be rolled, such as inside corners and pipework, so you don’t have to take out a brush to paint them.
A spray roller is also the ideal tool for applying blockfiller, using a large spray tip, say 31 thou’. (Blockfiller is a generic American product for painting blockwalls quickly and is now available in the UK).
Spray rollers are available for 9" and 18" non-perforated covers (the latter having twin spray heads). The roller frame takes the American 1" covers, but some models can be adapted to take the British 1" covers by bending the wires outwards.
Power Painting® Accessories
Pole-guns and gun extensions
Airless paint rollers
Extension poles
Spray shields
Zip Wall
Masking tape & film dispensers
Paint Strainers
Breathing Masks
Spray socks