How many coats of paint you need, and when one is enough

Two coats is the starting point

Benjamin Moore says to apply at least two coats of a top coat for the best hide and color development. Its step-by-step guide to painting a room says the same thing: let the first coat dry completely, then apply a second.

A second coat isn't a formality. The first coat leaves thin spots and lap marks where the roller overlapped, and the second evens them out. Color deepens, too. A wall that looks nearly right after one coat usually looks finished after two.

Here's a quick way to size up your own room:

The rows are a starting point, not a rule. A deep color over a pale wall, or a patchy old finish, can take a coat more, and the only way to know is to look at the first coat once it's dry.

When one coat can be enough

Benjamin Moore says one-coat coverage is sometimes achievable with its paint-and-primer products, but it still recommends two coats to get full color development and the best performance. Over previously painted surfaces, it says one or two coats can finish the job. On bare surfaces, it recommends two.

One coat is realistic when most of these are true:

• The wall is clean, sound and already painted.
• The new color is close to the old one.
• The paint hides well, which varies from can to can.
• You're touching up or refreshing, not changing the room.

"One-coat coverage" on a can is a claim about ideal conditions: a smooth wall, a close color and a clean surface. If your room isn't in those conditions, plan on two.

When you need more than two

• Dark to light. Dunn-Edwards says that when you change from a dark color to a light one, a primer is often the much less expensive choice compared with applying two coats of a top-quality finish.
• Stains. Dunn-Edwards says manufacturers typically recommend a specific stain-blocking primer to stop stains from bleeding through the finish.
• Deep, custom colors. Benjamin Moore says certain custom colors may need a deep base primer, tinted to a special formula, to reach the color you picked.
• Bare drywall and fresh patches. They soak up paint unevenly, which is why they need primer before the paint.

Our post on painting over dark paint covers the dark-to-light case in detail, and whether you need primer covers when to use it and which kind.

Primer counts, but it isn't a coat of paint

A coat of primer and a coat of paint do different jobs, so primer doesn't replace one of your two coats. It prepares the surface so the paint has something to hold onto, and it handles stains and porous spots that paint alone doesn't.

Outside, the effect can be dramatic. Dunn-Edwards cites testing by the Paint Quality Institute, which it describes as an independent industry research group, that found one coat of topcoat over a properly primed surface outperformed two coats of topcoat applied directly to wood. Primer is doing real work.

Waiting between coats

Dunn-Edwards puts the recoat time for latex at two to four hours, and says oil-based paint takes longer, with professionals often waiting 8 to 10 hours or even overnight. Benjamin Moore says to check the can for the recommended dry time and to wait until the paint is completely dry before the second coat.

Cool air, humidity and dark colors all stretch those times, and so do thick coats. Dunn-Edwards says a heavier film build can prolong the time solvent takes to leave, so rolling on one thick coat doesn't save you a second one. Our post on paint dry time versus cure time explains the difference between ready to recoat and fully hardened.

New drywall and patches

Fresh drywall is the case where the coat count surprises people. Dunn-Edwards says the seams, joint compound and raw wallboard all absorb paint differently, so without primer those areas show through as dull, blotchy spots. Its sequence is simple: prime, let it dry, then paint, and one even coat of primer is usually enough on standard walls.

1. One even coat of drywall primer, rolled on the wide areas and brushed in the corners.
2. Time to dry, per the label, with the room ventilated.
3. Two coats of paint, with the first allowed to dry completely before the second.

Small holes and repairs follow the same rule. On our jobs, small holes are repaired as part of the prep, and each repair is sanded smooth and primed before the paint goes on. Our guide to patching holes in drywall shows the repair itself.

Ceilings, trim and doors

The same logic holds in the rest of the room. Two coats of finish is the default, with primer where the surface is bare, stained or glossy. Glossy trim and doors need more prep than walls do, and our posts on painting baseboards and painting interior doors cover how that's handled.

Cabinets take more steps still. On every cabinet refinishing job, the cabinets are cleaned, degreased, sanded and primed before any paint goes on, which is why most kitchens take one to two weeks.

Why more coats isn't always better

Once the color is even and the old color is gone, another coat adds time and film thickness and nothing else. Piling coats onto a wall that's stained or in poor shape doesn't fix it. A stain needs a stain-blocking primer, and a patch needs sanding and priming, and no number of finish coats substitutes for that.

If you're trying to cover a problem, treat the cause first. If you're trying to change a color, plan the primer and the coats before you buy paint, and use our guide to how much paint you need to work out the gallons.

How we decide on a job

On every interior painting job, we protect the floors and furniture first, prep the walls (clean, sand, repair, prime), paint, clean up, and walk through the finished room with you. How many coats a room needs depends on what's on the wall and the color it's going to, and George can tell you after a phone call, or a visit if he needs to see the space.

Interior painting is priced by the square footage of the space, with paint included, and most rooms take one to two days. The written quote is the price, no extra charge if the job takes longer than expected.