Before you break out the roller and brush, there’s one painting step that can make or break your final result: prep. Whether you’re refreshing a single room or repainting your entire home, taking time to properly prepare your walls leads to smoother surfaces, better color payoff, and a longer-lasting coat. Skipping the prep might save time now—but you’ll end up spending more on fixes later.
At KDP Paintings, we’ve prepped and painted hundreds of homes across Long Island. We know firsthand how proper prep impacts the final product. Here’s how to do it right.
Clean Walls First—Always
No matter what type of paint you’re using—latex, oil based, or something in between—clean walls are non-negotiable. Even in rooms that look spotless, dirt, dust, oils, and even smoke residue can interfere with how paint sticks.
What You’ll Need:
- Warm water
- Mild dish soap
- Soft sponge or microfiber cloth
- Bucket or spray bottle
- Optional: TSP (trisodium phosphate) for tough grime
- Towels or rags for drying
How to Clean:
Step 1: Mix a few drops of mild dish soap into a bucket of warm water.
Step 2: Starting at the top of the wall, use a sponge or damp cloth to wash the surface in sections.
Step 3: For greasy areas, like kitchens, or high-touch zones, use a stronger solution or TSP.
Step 4: Use a circular motion and rinse with clean water as you go.
Step 5: Be sure to wipe down trim, molding, baseboards, and ceiling edges.
Step 6: Let the wet walls become completely dry before moving on to the next step.
It might feel like a chore, but this is one of the most important parts of painting walls. A clean surface helps paint stick evenly and prevents bubbling, streaks, or patches down the line.
Remove Wallpaper and Residue
Painting over wallpaper might seem like a shortcut, but it usually leads to peeling, bubbling, and a bumpy texture—especially with textured or older wallpaper.
How to Remove Wallpaper the Right Way:
Step 1: Score the wallpaper lightly with a utility knife or wallpaper scorer.
Step 2: Spray with warm water and vinegar (or use a commercial wallpaper remover).
Step 3: Let it soak for 15 to 20 minutes so the adhesive softens.
Step 4: Peel the paper away gently with a putty knife, starting from a seam or corner.
Step 5: Scrub away any leftover glue using warm water and a sponge.
Step 6: Rinse and let the surface dry completely.
If you’re working with multiple layers of old wallpaper or stubborn glue, a steamer can help lift it off. Or, if the process feels overwhelming, our team at KDP Paintings is happy to handle it for you.
Repair Holes, Dents, and Cracks
After cleaning and wallpaper removal, you’ll probably notice imperfections you didn’t see before—nail holes, minor dents, small cracks, or rough patches. These should all be addressed before any paint goes on.
What You’ll Need:
- Lightweight spackle or wall repair compound
- Putty knife
- Sanding block or fine-grit sandpaper
- Dry cloth
How to Repair:
Step 1: Use a putty knife to apply spackle over any holes, cracks, or gouges.
Step 2: Feather the edges so they blend into the wall—don’t leave a mound.
Step 3: Allow the spackle to dry thoroughly (usually a few hours, or overnight for larger areas).
Step 4: Sand the area until it’s flush with the wall and feels smooth to the touch.
Step 5: Wipe away any dust with a dry cloth.
Filling small holes might seem optional, but once the paint dries, those spots will stand out. Fixing them now makes for a polished, even coat later.
Smooth Out Uneven Surfaces
Even if you don’t need major repairs, sanding can help eliminate texture left behind from previous paint jobs or patchwork. If your walls were previously painted with a semi-gloss or gloss finish, sanding is especially important for helping the new coat grip the surface.
Sanding Tips:
- Use medium-grit sandpaper (120–150) for rough spots.
- Use fine-grit (180–220) for glossy or previously painted walls.
- For best results, use a sanding block to keep even pressure.
- Sand in a circular motion and work from top to bottom.
- After sanding, wipe the surface clean with a dry microfiber cloth or vacuum with a brush attachment.
Don’t forget to look at the wall from different angles in good lighting—you’ll catch uneven surfaces that may not be visible straight on.
Tape and Cover What Matters
Prep doesn’t stop at the wall. You’ll want to protect everything around it—especially trim, floors, furniture, and light fixtures.
Supplies to Gather:
- Painter’s tape
- Canvas drop cloths
- Plastic sheeting or old sheets
- Masking tape
- Screwdriver for removing outlet covers
Prep Steps:
Step 1: Use painter’s tape to line trim, baseboards, window sills, and ceilings.
Step 2: Press the tape down firmly along the edge to prevent paint bleeding.
Step 3: Cover floors with canvas drop cloths—they’re heavier, safer, and less slippery than plastic.
Step 4: Remove outlet and switch plates and tape over the openings.
Step 5: Drape plastic sheeting or an old sheet over any furniture that can’t be moved.
Proper prep here saves you time on cleanup—and helps keep your final product sharp and professional-looking.
Know When to Use Primer
Primer doesn’t just help paint stick—it also hides stains, seals patches, and creates a uniform base coat, especially when you’re changing wall colors dramatically.
You’ll Want to Prime If:
- You’re painting over dark colors with lighter ones
- You’ve sanded or patched areas
- You’re painting bare drywall
- You’re covering glossy or oil based paint
- The walls have water stains, smoke damage, or other discoloration
Apply primer using a roller for larger areas and a brush for corners or trim. Allow it to dry completely before applying paint.
Get Your Tools and Paint in Advance
Nothing slows down a paint job like stopping to dig for tools mid-project. Getting everything organized ahead of time will make the process smoother from start to finish.
Checklist:
- Paint (plus 10–15% extra)
- Roller and roller cover
- Angled brush for edges
- Paint tray and liner
- Stir sticks
- Painter’s tape
- Drop cloths
- Stepladder
- Clean rags or paper towels
- Bucket of warm water and sponge (for spills or drips)
Set up a staging area with all your tools in one place—ideally near a sink or outlet.
Do a Final Walkthrough Before Painting
Once your tools are prepped, your walls are clean, and your surfaces are covered, take a final walk around the room.
- Look for patches that feel rough or look inconsistent in texture or color.
- Use your hand to feel for bumps or uneven areas.
- Use good lighting to check corners, ceiling lines, and trim edges.
- Wipe down the walls one last time with a dry cloth or clean, slightly damp sponge.
- Let all surfaces become completely dry before you start painting.
A few extra minutes here can make the difference between a decent paint job and one that looks like it came straight out of a magazine.
Why Hire a Professional Painter Instead?
Let’s be honest—painting walls isn’t always quick or easy. And prep work? That’s where most DIY jobs fall short. From washing and patching to priming and cutting in edges, each step has an impact on the final product.
If you don’t have the time, tools, or energy to prepare properly, professional painters can take the stress off your plate and deliver a result that looks better and lasts longer.
Here’s why homeowners on Long Island choose KDP Paintings:
- We handle all the prep: wash, sand, patch, prime, and tape
- We know how to spot and fix uneven surfaces before painting
- We help you choose the right finish and products for your space
- We use professional tools and techniques for a flawless final coat
- We leave your home cleaner than we found it
Whether you’re updating a bedroom, refreshing a kitchen, or painting walls throughout your home, our experienced Medford painters will handle every step—with less mess, fewer mistakes, and results you’ll love.
Good Prep Makes a Great Project
Prepping your walls might feel like a long checklist, but it’s the foundation of a quality paint job. A little effort now helps the paint go on evenly, cover better, and last longer. Whether you’re working with latex paint or oil-based paint, how you prep the surface matters just as much as the paint you choose.
Rather leave it to the pros? Watch how KDP Paintings handles prep work and painting from start to finish—so you can skip the stress and enjoy the finished result. Contact us via our website or give us a call at 631-948-5272 today to schedule your free estimate.
