Interior painting: 3 pro secrets that DIY skips
Every homeowner has painted a room at some point. And every homeowner has watched that paint job peel, chip, or look patchy after a year or two.
Here's the truth: the paint itself is almost never the problem. It's the prep — the boring, time-consuming work that nobody wants to do — that determines if your paint job lasts 2 years or 15.
Here are three prep steps DIY painters almost always skip.
Secret #1: Wash the walls (yes, actually wash them)
Walk into a bathroom or kitchen. Now imagine years of cooking grease, hair spray, or shower steam settling on those walls. That film is why paint doesn't stick.
Professional painters clean walls with TSP (trisodium phosphate) or a similar degreaser before priming. In a kitchen, this alone doubles the lifespan of the paint job.
For a whole-room clean: warm water, TSP substitute (TSP-PF works fine), sponge. Wipe walls top to bottom. Let dry fully.
Skip washing, and you're painting over dirt. The paint bonds to the dirt, not the wall. It peels off within a year.
Secret #2: Prime bare drywall and patched areas
New drywall or drywall you've just patched drinks paint. If you skip primer, your topcoat looks blotchy, uneven, and needs 3+ coats to look uniform.
Primer is cheap ($25-40 per gallon) and covers 300-400 sqft. It:
- Seals porous drywall so topcoat doesn't soak in
- Blocks stains from bleeding through
- Creates a uniform surface for color
- Saves you a whole coat of expensive finish paint
Use a shellac-based primer (Zinsser BIN) for water stains or smoke damage — regular primer won't block it, and stains will bleed through.
Secret #3: Sand between coats
This is the one most people skip and it makes the biggest visual difference.
When paint dries, it raises tiny wood fibers on drywall paper and creates microscopic bumps. If you paint over those bumps, they get locked in. The finish feels gritty forever.
Pros lightly sand between primer and first coat, and between first and second coat. Use 220-grit sandpaper on a sanding block. Just enough to knock down the fuzz — you're not really removing paint.
The result: a finish that feels like glass instead of sandpaper.
Bonus: Buy pro-grade paint
Not all paints are equal. The $25/gallon at Home Depot builder-grade paint has 30-40% solids. Pro-grade paint has 50-60% solids. That means more pigment per coat, better coverage, and a longer lifespan.
My go-to lines:
- Sherwin-Williams Emerald — best interior paint I've used. Washable, low VOC, coverage is excellent.
- Benjamin Moore Regal Select — close second, excellent for cabinets.
- Sherwin ProClassic — my go-to for cabinets and trim.
Cost: $60-90/gallon. Sounds expensive until you compare — one coat of Emerald often replaces two coats of builder-grade, saving time and materials.
The right order of operations
- Move furniture, cover floors
- Wash walls (TSP or degreaser)
- Patch any holes, sand smooth
- Prime bare drywall and patches
- Caulk any gaps at trim, corners
- Lightly sand primed areas
- First coat of finish paint
- Lightly sand
- Second coat of finish paint
- Cleanup, touch-ups the next day
Skipping steps 2, 4, or 6 is what makes DIY jobs look like DIY. Do them, and your paint job holds up for 10-15 years.
Not sure if it's worth doing yourself?
Painting takes 10-15 hours per room done right. If your time is worth more than what you'd save, hiring a pro pays off. Send me photos and I'll give you a real quote.