Should interior walls be sprayed or rolled?

Short answer: spray big empty spaces, roll lived-in rooms

Spraying suits large, empty rooms. Rolling suits furnished rooms and small jobs. Wagner, a sprayer maker, says new builds need less masking because the floors often aren't laid yet, and that the larger the area, the easier an airless unit is to work with. In a small room, Graco suggests a pressure roller instead if you'd rather not spray inside. Here's how the two compare, factor by factor.

Neither one wins everywhere. The deciding question is how much has to be covered before the first drop of paint goes on.

Finish: a sprayer leaves no roller texture

A sprayer lays paint on without touching the wall, so there's no roller stipple. Wagner says spraying means you don't risk brush, hair or roller marks. It also says a roller's fibres can reach into the paint already on the wall and lift it in places. That's a sprayer maker talking, so treat it as its view.

A roller still gives a good, even finish when it's used the way the paint makers describe. For Wash&Wear Low Sheen, Dulux says to cut in around the edges with a brush, then roll up to that border while it's still wet. It says to apply two coats, with the first completely dry before the second. For Wash&Wear +PLUS Anti-Scuff, Dulux says to use a medium nap synthetic roller, and that poor quality or worn rollers can affect the final finish.

Sprayed walls aren't automatically perfect either. Dulux says tilting the gun gives an uneven finish, and fanning it causes an uneven finish and overspray. The sheen you pick matters as much as the tool. Our guide to interior paint finishes covers which sheen goes on which wall.

Speed vs masking: the spraying is fast, the masking isn't

Spraying is quick once you start, but a lived-in room takes real time to mask first. Haymes says an airless sprayer finishes projects faster, with a continuous, high-pressure stream of paint. Graco says a sprayer can repaint a room in a fraction of the time a roller or brush takes. Neither of those counts the masking. Here's what Graco and Wagner list before you spray a room:

• Furniture out, or to the middle. Graco says to move any remaining furniture to the centre of the room and cover it completely.
• Doors, windows and trim. Graco says to apply masking tape and protective paper around and over them.
• Switches and power points. Graco says to tape over them. Any work on wiring or fittings is a job for a licensed electrician.
• Vent covers. Graco says to remove heating and air conditioning vent covers.
• Floors and ceiling. A project guide on Wagner's site masked the floors with flooring paper and the ceiling with tape and plastic.
• Rooms you're not painting. The same guide suggests walling them off with plastic taped or stapled to the ceiling.

Rolling skips most of that list. You still need drop sheets and tape along the edges. That's why the sprayer makers point to empty rooms and new builds, where most of the list is already done.

Paint use and overspray: pressure decides how much drifts

An airless sprayer always loses some paint to the air. Pressure decides how much. Graco says overspray can't be avoided when airless spraying, but it can be cut by reducing pressure. Dulux says too much pressure results in overspray and extra paint usage. Wagner says unnecessarily high pressure also wears the unit and nozzle faster.

The fix the makers agree on is the lowest pressure that still gives an even fan. Dulux says to start low and increase it until the spray pattern is even. Graco says to test on cardboard and raise the pressure until the lines at the top and bottom of the pattern go away. A worn tip wastes paint too. Graco says a worn tip sprays a smaller fan with the same amount of paint, so you'll need more paint to finish.

Sprayer makers also sell lower-pressure machines. Wagner says its High Efficiency Airless sprayers make up to 55% less overspray than conventional airless, which means less masking and less paint lost. Haymes says some advanced models have control settings that cut wastage and overspray.

Indoors there's one more kind of loss. The Wagner project guide says spraying inside makes some paint dust, which is paint that dries before it reaches the wall. Masking keeps it off everything else. Working out how many litres a room takes? Our guide on how much paint you need does the sums.

Where a sprayer earns its place inside

Inside a house, a sprayer makes the most sense where there's a lot of wall and very little to protect. These are the cases the paint and sprayer makers point to:

• New builds before move in. Wagner says the masking is lighter because floors often aren't laid yet. Our page on interior painting in Aura covers painting a new house before the furniture arrives.
• Whole-house renovations. Wagner pitches its DIY airless machines at complete interior or house renovations, with walls and ceilings, doors and frames to paint.
• Textured ceilings. Graco says rolling a textured ceiling takes time and can make the texture flake off, and that spraying keeps the texture.
• Doors and trim, laid out in one room. The Wagner project guide took the doors off their hinges and sprayed them in one well-masked room, using a fine finish sprayer rather than the wall machine.

Dulux lists spray as an application method, alongside brush and roller, for both Wash&Wear Low Sheen and Ceiling White. For a ceiling on its own, Graco says to protect the walls with paper, plastic or a spray shield held tight at 45 degrees into the corner. Rolling a ceiling is covered in how to paint a ceiling.

How to spray an interior wall, step by step

To spray a wall, prep and mask it, set the lowest pressure that gives an even fan, then spray top down in overlapping passes. These steps are drawn from the Haymes, Dulux and Graco spraying guides.

1. Clean and fill. Haymes says to clean the surface of dust, dirt and debris. Graco says to fill nail and screw holes, then sand rough areas once dry.
2. Mask. Haymes says to cover everything you're not painting with drop cloths or plastic sheeting. Use the masking list above.
3. Pick the tip. Dulux lists a 0.015 to 0.019 airless tip for broadwall acrylic paint. Graco says a 0.015 or 0.017 tip typically suits interior walls, and that indoor paints take smaller tips than outdoor ones.
4. Check the thinning on the label. Haymes says to thin paint to the sprayer's specifications. Dulux allows up to 30ml of water per litre for airless spraying of Wash&Wear +PLUS Anti-Scuff, and up to 125ml per litre for Professional Interior Matt. Different paint, different limit.
5. Test on cardboard. Haymes says to test the gun on cardboard to adjust the flow and pattern. Start at low pressure and raise it until the fan is even.
6. Edges first. Graco says to start at the top of the room, work in sections, and spray the outer edges first. For inside corners, it says to aim the tip into the corner so the spray covers both sides.
7. Fill the flat areas. Haymes and Dulux both say to hold the gun about 30cm from the wall. Dulux says to hold it straight to the surface. Overlap each pass by about 50%, as Haymes and Graco both say.
8. Second coat on the label's timing. Dulux lists Wash&Wear Low Sheen as touch dry in 30 minutes and ready to recoat after 2 hours.
9. Take the tape off once it's dry. Graco says to allow plenty of drying time before removing tape from trim, for clean lines.

Rolling instead? The step by step is in how to paint a room.

Sprayer safety: high pressure can pierce skin

An airless sprayer is a high pressure tool, and the makers treat it that way. Haymes describes it as pumping paint at high pressure through a hose and out a spray tip. Dulux warns that high pressure fluid from the gun, a leaking hose or a failed part will pierce the skin.

• Make it safe. Dulux says to make the machine safe when changing tips or leaving it, keep your fingers behind the trigger when you're not spraying, and use the safety trigger when the gun isn't in your hand.
• Cover up. Graco lists gloves, safety glasses or goggles, a spray sock or hat, dust masks and respirators. Wagner says to always wear a respirator mask plus protective clothing when spraying wall paint.
• Air the room. Haymes says to make sure the area is well ventilated. Graco says the same.

Follow the safety section of your sprayer's own manual. Don't take a pump apart beyond what the manual covers. Anything to do with wiring, switches or power points beyond taping over them is a job for a licensed electrician.

What it means for your quote: ask what the masking covers

Whether a painter sprays or rolls changes where the hours go. With a sprayer, more of the work happens before any paint goes on, masking and protecting the room. With a roller, more of it happens on the walls. So when you compare quotes, ask which method they'll use in each room and what the masking covers, including floors, windows, fittings and any rooms next door.

In Queensland, the QBCC says a licence is needed to contract for building work valued over $3,300. A handyman can only take on jobs up to that value without one. We hold QBCC licence 1281728. Our interior painting cost guide shows what a repaint costs by house size. For help with your own place, our interior house painters work across the Sunshine Coast. Check the locations page for the suburbs we cover, or get a guide price from the instant estimate.