Apply Full Primer Coat to Walls
This is where your prep work pays off. Applying a full coat of primer creates the perfect foundation for your paint, ensuring even coverage, true color, and professional results. Master the W-pattern technique and wet edge method to prime like a pro.
Quick Summary
Time needed
2-3 hours per room
Cost
$30-50
Difficulty
Moderate
Why Primer Makes All the Difference
Primer isn't just diluted paint. It's specially formulated to seal porous surfaces, block stains, and create a uniform base for your paint to grab onto. Think of it like putting on a base coat before nail polish—it makes the color coat go on smoother and last longer.
The payoff: A properly primed wall means your paint will cover in fewer coats, the color will be truer, and you won't see bleed-through from old paint or repairs. It saves you money and time in the long run.
Professionals almost always prime, even when the paint can says "no primer needed." That's because they know primer gives them better results, period. Now you'll know the technique too.
What You'll Need
Materials
- •Wall primer (1 gallon per 400 sq ft)
- •Paint tray liner (makes cleanup easy)
Tools
- •9-inch roller frame with extension pole
- •3/8-inch or 1/2-inch nap roller cover (smooth to semi-smooth walls)
- •2-3 inch angled brush
- •Paint tray
Step-by-Step Guide
1. Cut In the Edges First
Before you start rolling, use a brush to "cut in" a 2-3 inch border around all edges where the roller can't reach.
Areas to cut in:
- •Ceiling line (where wall meets ceiling)
- •Inside corners where two walls meet
- •Around door frames and window trim
- •Along baseboards
Tip: Use the tip of your angled brush for precision. Load the brush about 1/3 full—too much primer will drip, too little won't cover. Wipe excess on the edge of your paint container.
2. Load Your Roller Properly
The right amount of primer on your roller makes all the difference between smooth coverage and drips or thin spots.
Roller loading technique:
- 1.Pour primer into paint tray, filling the deep well about halfway
- 2.Dip roller into primer and roll it on the ridged slope to distribute
- 3.Repeat 3-4 times until roller is evenly saturated but not dripping
- 4.Roll off excess on the ridged area—roller should feel substantial but not heavy
3. Use the W-Pattern Technique
This professional technique distributes primer evenly and prevents lap marks and stripes.
The W-pattern method:
- 1.Start near the top of the wall (a few inches from the ceiling)
- 2.Roll upward at an angle to form one leg of the W (about 3 feet long)
- 3.Without lifting the roller, roll down at an angle to form the middle
- 4.Continue to complete the W shape (or M shape)
- 5.Still without lifting, fill in the W by rolling horizontally and vertically
- 6.Finish with light upward strokes to blend and remove roller marks
Important: The key is not lifting your roller until you've filled in the entire W section. Lifting creates starting and stopping points that show as lines in your finish.
4. Maintain a Wet Edge
This is the professional's secret to invisible seams. Always roll new primer into wet primer—never onto dried primer.
How to keep a wet edge:
- •Work in 3x3 foot sections—small enough to stay wet while you work
- •Overlap each new section with the previous one by a few inches
- •Work across the wall continuously—don't stop in the middle
- •If you must take a break, finish the entire wall first
Tip: In hot weather or dry conditions, primer dries faster. Work quicker or add a paint conditioner like Floetrol to extend the working time.
5. Work Top to Bottom, Wall by Wall
Strategy matters. Start at the ceiling line and work down so any drips land on unpainted wall.
Room coverage strategy:
- 1.Cut in the entire room first, or cut in one wall at a time
- 2.Roll the first wall starting from top left (or top right if left-handed)
- 3.Work across in vertical strips using the W-pattern
- 4.Finish the entire wall before moving to the next
- 5.Move around the room clockwise or counterclockwise
6. Check Your Work and Touch Up
Once you've finished, inspect your work from different angles and in different lighting.
What to look for:
- •Thin spots or missed areas (will look darker or patchy)
- •Drips or runs (catch these while wet)
- •Roller marks or texture from too much pressure
- •Edges where you can see lap marks
Pro Tips
Pro tip: Use an extension pole even for walls you can reach. It gives you better leverage and reduces arm fatigue, plus you get better coverage because you're not working at an awkward angle.
Pro tip: Don't press hard on the roller. Let the roller do the work with light, even pressure. Pressing hard squeezes out too much primer and creates texture and splatter.
Pro tip: For large rooms, two people make it easier to maintain a wet edge. One person cuts in ahead while the other rolls.
Frequently Asked Questions
Do I really need to prime walls before painting?
For new drywall or significant color changes, yes. Primer seals porous surfaces, ensures even paint absorption, and helps paint adhere properly. You can skip primer if you're repainting walls in similar colors and the existing paint is in good condition. Many premium paints advertise "paint and primer in one" but a separate primer coat still gives better results for problem areas.
What does "maintaining a wet edge" mean?
A wet edge means always rolling new primer into primer that's still wet, not dried. When primer dries and you paint over it, you create a visible line or lap mark. Work quickly enough that each new section overlaps wet primer from the previous section, creating a seamless blend.
What's the W-pattern and why does it matter?
The W-pattern (or M-pattern) is a professional technique where you roll primer in a large W shape, then fill it in. This distributes primer evenly and prevents the striped look from rolling only up and down. It also helps you work faster and maintain that crucial wet edge.
Ready for the Next Step?
Now patience is your friend. Give the primer proper time to dry before moving on to painting.