Interior Painting Tips: Best Practices from an Expert

You could say that painting found Mauro, rather than the other way around. Recently arrived from his native Brazil, he was working on a construction crew, hoping to become a carpenter, when the painter on the job didn’t show up. “My boss looked at me and said, ‘Can you paint?’ I said, ‘I can try,’ and picked up a brush,” he says. “I found I really enjoyed the work.”

After the job was done, he started practicing at home—”on the walls, inside closets, windows, trim, everywhere”—and making a study of his new craft. “My dad taught me to be very detail-oriented,” Mauro says of his handyman father. That meticulousness paid off: He got more and more jobs, eventually opening his own business.

Then one day he found himself painting at the home of Russ Morash, creator and longtime producer of This Old House—though he had no idea who “Russ” was. Impressed with his work, Morash gave the young painter an on-camera role at the Newton project house. A segment on Ask TOH followed, and Mauro eventually earned an official place on the TOH team.

We caught up with him on a recent job, painting a colorful kids’ room in Somerville, MA. Here’s a look at the steps he takes to deliver a first-class interior paint job—and you can too.

How to Prep a Room for Paint: Step-by-Step

1. Remove hardware. Take off window locks and lifts, doorknobs and strikes, electrical cover plates, and light fixtures. Tape the screws to each piece of hardware and label its location; store the items together in a bucket—this makes reinstalling them easier later on.
2. Clear out obstacles. Whenever possible, relocate furniture to another room so that you can easily navigate the space where you’ll paint. Cover whatever can’t be removed with plastic sheeting, and clear a pathway that’s at least 3 feet wide.
3. Protect floors. Pros generally avoid using painter’s tape—it’s time-consuming to apply. One place Mauro always tapes: along the bottom of baseboards. Then he tapes a wide border of rosin paper to this strip of tape, and covers the rest of the floor with plastic-lined canvas drop cloths—these prevent any spilled paint from seeping through. “Protecting the floor will save you time, and headaches, in the long run.”
4. Fill holes, gaps, and cracks. Closely inspect walls and trim for imperfections; patch holes, dents, and dings by using ready-mix spackle on walls or wood filler on trim. On plaster walls, Mauro uses joint compound and mesh tape on wide cracks and flexible patching compound on smaller ones. Fill gaps around the trim by cutting a caulk tube close to the tip and running a small bead, pressing down and pulling the caulk gun toward you as you work; then run a wet finger on it to smooth it out.
5. Sand and remove dust. To create a smooth, even surface for painting, scuff-sand moldings, doors, and windows with 220-grit paper. Use a pole sander with 120-grit paper to smooth walls. (If you’re working on paint that could be more than 45 years old, be sure to test for lead first.) Thoroughly remove sanding dust with a vacuum equipped with a HEPA filter, followed by a damp rag or tack cloth

TOH Pro Tip: Don’t over-caulk gaps. Cutting the tip of the tube too big results in messy joints. Measure the gap, and use a caulk tube that’s marked with lines indicating where to cut depending on the size of the gap. Or start small, near the end of the tip, and adjust as needed.

Choosing the Best Primer

Primer isn’t always necessary—if you’re recoating walls and trim that are in good condition and were previously covered in a similar shade and formulation, for instance. But with new drywall and fresh plaster, primer is essential to seal the surface. And if you’re applying a light color over a dark one, the previous paint job is damaged or deteriorated, or you’re coating a porous or slick surface, using an appropriate primer will ensure optimal coverage.

• Walls: A general-purpose water-based, 100-percent latex formula should do the trick here. If you’re making a big color change, ask your paint store to tint the primer to ensure even coverage.
• Bare wood trim: Mauro relies on oil-based primer for this: “It fills and seals the pores so that whatever paint you use will adhere well.”
• Painted wood trim: For trim previously painted with latex, a water-based latex primer is fine. But if you’re unsure what type of paint was used, you may want to use one that’s oil-based.
• Clear-coated wood trim: If the trim has a coat of polyurethane or varnish, shellac primer will provide the best adhesion. Note: Since both oil-based and shellac primers give off volatile organic compounds (VOCs), which can damage your lungs, be sure to work in a well-ventilated space.
• MDF: For medium-density fiberboard moldings or built-ins, choose shellac- or oil-based primer; water-based formulas can cause the material to swell and crumble.
• Masonry: Got an exposed brick wall or chimney indoors? Seal the pores with a water-based latex primer.
• Metal: Use an oil-based primer on ferrous metals, which contain iron, to prevent rust, and a water-based latex metal primer on nonferrous surfaces.
• Plastic: If you’re painting laminate, go with a bonding primer, a modified acrylic formulation made to adhere to slick surfaces.

Must-Have Painting Tools

1. Paintbrush: “Always buy high-quality brushes,” says Mauro. “They’re built to last and don’t leave bristles behind on surfaces.” For latex paints, that means brushes with synthetic bristles—a 2½-inch angled sash brush is his go-to for cutting in. For detail work, he likes a 1½-inch sash brush, and to cover large, flat areas, a 3-inch straight brush. He uses natural hog hair (a.k.a. China bristle) brushes with oil-based paints and disposable foam brushes for one-time touch-ups. SHOWN: 2.5-inch Clearcut Glide nylon-polyester bristle brush; amazon.com
2. Paint roller and roller covers: Mauro relies on lint-free microfiber covers. He chooses from three naps: ¼ inch for smooth surfaces, 3⁄8 inch for semi rough surfaces (most common indoors), and 1 inch for textured surfaces. Starting with a sturdy roller frame, he adds a screw-in extension pole for coating ceilings and other hard-to-reach areas. SHOWN: 9-inch Sherlock roller frame and 3⁄8-inch Pro/Doo-Z woven roller cover (striped), amazon.com; 3⁄8-inch Ultra Finish woven microfiber roller cover (white), amazon.com
3. Painter’s tool: Mauro uses this classic multi- tool for scraping out joints, cutting tape, prying open cans, cleaning roller covers, and more. This version boasts many more features than the original 5-in-1. SHOWN: Clauss Non-Stick STIFF 14-in-1.Painter’s Tool; amazon.com
4. Pole sander: A sanding head fitted with 120- grit sandpaper and a pole smooths walls for painting. “Sweep the sander side to side as you work your way from the top down,” Mauro advises. SHOWN: 3M Drywall Pole Sander; amazon.com
5. Painter’s tape: To mask off finished surfaces, like floors, Mauro uses low-tack painter’s tape; he burnishes the edge with a putty knife to ensure there’s no bleed through. SHOWN: FrogTape Delicate Surface Painter’s Tape; amazon.com
6. Caulk gun: Mauro likes a manual gun that has a built-in tip cutter and a hinged steel pin for puncturing the seal on a tube of good-quality, paintable white acrylic caulk. SHOWN: Dripless ETS2000 caulk gun; amazon.com

TOH PRO TIP: “Always buy top-of-the-line paint. It costs a little more per gallon, but it goes on better, looks better, and gives you a more durable finish. will last longer.”

Make a Plan: What to Paint When

Following a logical order for any paint project is crucial, Mauro says. “It saves time and protects your work—you won’t be brushing up against or dripping paint on wet surfaces, so you won’t have to redo them.” The general approach: work top to bottom.

1. Start with the ceiling. First, cut in a 1½- to 2½-inch-wide band along the perimeter with an angled sash brush (see “Technique Basics,” opposite), then use a roller on an extension pole to cover the broad expanses. Do two coats. “If you miss any drips, spatter, or errant brush marks on walls or trim, you can fix them as you move on,” says Mauro.

2. Then paint the trim, windows, and doors. Tackle crown molding first, followed by windows and their casings, then doors and their casings. If you have the space, remove doors to another work area where you can lay them flat; paint them while the rest of room is drying. Finish by painting any wall paneling or other trim.

3. Cut in and roll the walls. With much of the detail work out of the way, you can paint the walls. This is an opportunity to create a crisp border with previously painted surfaces if the line is uneven.

4. Paint baseboards last. Since you’re working with gravity, any fallen paint droplets that you missed cleaning up can be addressed now. Start by cutting in along the top of the molding, then work your way down to the floor.

How to Hold a Paintbrush

The right grip allows you to control the flow of paint. Start by holding the brush like a pencil, with your index finger touching the ferrule along the narrow edge, your thumb on one side, and your remaining three fingers on the other. This works well when cutting in. “But it’s okay to adjust your grip as you go, depending on what you’re doing,” says Mauro. “It helps fight hand fatigue.”

How to Load a Paintbrush

Never dip your brush into a can of paint. “You risk contaminating the whole can if debris or dust gets in,” says Mauro. Always pour paint into a small paint pail; fill it about halfway. “To load the brush, dip the bristles into the paint about the width of two fingers,” he says. “This prevents dripping, and also prevents you from having to clean the entire brush when you’re done, which saves time.” Tap it lightly against the side of your bucket to work the paint into the bristles and remove any excess.

How to Cut in with a Paintbrush

When painting a room, you want to start where two surfaces meet and a roller can’t reach: where a wall meets the ceiling, where a wall meets another wall, and along trim and baseboards. These areas call for a special brush sequence, called cutting in.

Starting position: Beginning in a corner, place the brush’s bristles against the wall about 1/2 inch below and nearly parallel to the adjacent surface. Gently push them up to that edge.

First stroke: Angle the leading edge of the brush slightly away from the edge of the adjacent surface as you pull the brush in one smooth stroke, about 12 to 14 inches long. Apply light pressure at first and increase the pressure slightly near the end of the stroke, pulling the brush down slightly and away from the edge you’re cutting in. Go back and smooth out any visible brushstrokes on the lower edge, brushing in the same direction.

Second stroke: Position your brush about 12 to 14 inches away from the first stroke and repeat the steps above, moving in the opposite direction. Continue across the wall, always placing the brush on drywall and pulling it into the fresh paint left by the previous stroke, until you reach the next corner.

How to Roll a Wall

Moderate, even pressure is the key to smooth, even coverage

Fill the paint tray’s reservoir below the ridges. Dip the roller cover in, then distribute the paint evenly by rolling the cover over the ridges. “If the roller is covered with paint, you have enough,” says Mauro. “It shouldn’t be dripping.”

Starting near the top, at the edge of the cut-in area, place the roller flat on the wall; roll on the paint in a W or N shape, overlapping the previous stroke by 30 to 40 percent as you fill in the gaps. Don’t press too hard or try to stretch the paint toward the end; this can cause ridges to form. Focus on applying a smooth, even coat, working in a 3- to 4-foot-square area.

When you’ve covered the wall, run a lightly loaded roller along the perimeter to blend in the texture of the brushstrokes you made while cutting in.

Let the walls dry for about 1½ hours, then repeat the cutting in and rolling sequence to apply a full second coat.

TOH Pro Tip: Make a custom-fit disposable paint-tray liner with aluminum foil. Buy a roll that will cover the full width of the tray, up the sides, and around the edges. Carefully press down a foil sheet so that it conforms to the contours of the tray and won’t shift around. When you’re done, you can peel it off and toss it.

A Quick Guide to Paint Finishes

Paint comes in a variety of light-reflecting sheens. Here’s how Mauro approaches which one to use where

Flat: The lowest sheen, which means the paint soaks up the available light. “It’s ideal for no-traffic areas like ceilings and hides surface imperfections.”

Matte: A slightly reflective sheen that’s a bit more durable, and hides minor imperfections. While not as washable as paints with more sheen, it takes touch-ups better if the painted surface gets scuffed later on. Excellent for low-to-moderate-traffic areas like bedrooms.

Eggshell: A soft, velvety sheen with a bit more luster than matte paint, more stain resistance, and more washability. “It lends itself to areas with moderate to high traffic, such as kitchens, bathrooms, and hallways, where durability is essential.”

Satin: A glossier sheen with a pearl-like appearance. It’s easy to clean, so it is well-suited for cabinets.

Semigloss: A sleek, radiant sheen that’s scrubbable. Mauro’s choice for trim, doors, and playrooms.

High gloss: A brilliant shine with a glassy sheen. Mauro uses it to add vibrancy to entry doors, accent walls, or ceilings.

How to Paint Divided Lights

Whether you’re working on windows or doors, taping off glass is time-consuming. Mauro knows a better way

1. Prep the glass. In lieu of tape, use a 2-inch square-tipped brush to apply a wide band of liquid mask along the edges of the glass (Associated Paint Masking Liquid H2O; amazon.com). When the opaque liquid dries clear, brush on a second coat. When the second coat is dry, you’re ready to paint.
2. Paint the muntins. Use a small 11/2 -inch angled sash brush to cut in along the inside edges of the muntins; then paint the flat fronts.
3. Paint the perimeter. Using the same brush, coat the stiles and rails. Allow the paint to dry for at least 90 minutes. Then repeat Steps 2 and 3 to apply a second coat.

How to Paint a Straight Edge without Painter’s Tape

Sometimes painter’s tape just isn’t an option: maybe a side casing is too close to an inside corner, or you’re painting the outside edge of a window sash. Then Mauro uses a wide putty or taping knife as a guide. Here’s how:

1. Holding the blade between your thumb and remaining fingers, place it along the edge you want to paint. Grip it firmly, but make sure you can slide it.
2. Touch the bristles of the paintbrush to the surface in front of the knife and slowly drag both hands down the joint at the same pace.
3. Stop when paint starts to accumulate on the blade. Carefully lift it straight off to keep paint from bleeding onto the adjacent surface. Wipe the blade clean.
4. Continue down the joint in the same manner. Once you reach the end, flip the brush over and paint in the opposite direction to smooth out your brushstrokes.

TOH Pro Tip: “The sheen you select can have a big effect on the final product, both in terms of how it will look and how it will wear. Be sure to factor in the condition of your walls or trim, as well as how much traffic it will be subjected to.” — Mauro Henrique

Paint Clean-Up Tips

Take the time to carefully remove protective coverings and thoroughly clean the tools you’ve invested in.

• Remove dried masking liquid: First, make sure paint is dry—it’s best to allow 90 minutes. You don’t want the paint to peel off along with the protective barrier. Use a utility blade to score the mask along the edges of the glass; then lift it off in one piece (left).

• Pull up painter’s tape: Once paint is dry, carefully pull off painter’s tape at a 45-degree angle to keep from taking paint with it (below left). If the edge is sealed with paint, score along the paint line with a putty knife first.
• Clean paintbrushes: To get rid of latex paint, run the brush under warm water with the bristles pointed down; use your fingers to work a few drops of dish detergent into the bristles, keeping water away from the ferrule. Press bristles up against the sink wall and scrub off any stuck-on paint with a plastic or nylon scrub pad. Avoid aggressive metal combs and brushes, says Mauro; they can damage the bristles. To clean off oil-based paint, swirl the bristles in odorless mineral spirits.
• Remove excess moisture with paper towels, then spin the brush handle between your palms: Never place wet brushes in a container with the tips up, where moisture can seep into the metal and cause it to rust. Lay brushes flat or hang them on a hook to dry, then store them in their original sleeve to keep the bristles in shape.
• Clean paint-roller covers: First, run the curved blade of a 5-in-1 tool down the cover to remove the paint. With latex paints, pull the cover halfway off the frame and run it under warm water, using a hand to push the paint out of the fibers. With oil-based paint, pour solvent into a paint tray and dip and roll the cover in the tray a few times; replace with clean solvent for a final rinse. Blot the cover with paper towel, and stand it on end to dry.