Should I Paint Ceiling Parallel or Perpendicular to Window? We Answer

Different interior parts have unique considerations that require your focus when painting them. The ceiling is one such part. You may paint the ceiling as part of a general project involving other parts of a space, like the walls and baseboards, or by itself. You might be seeking clarity on whether to paint the ceiling to the window. Perpendicular or Parallel?

We intend to answer that question. This article will treatise whether one of these techniques is preferable and explain why. As a bonus, we will give you general instructions and tips for painting the ceiling.

Painting The Ceiling: Parallel or Perpendicular to The Window?

This question is important because of how shadows appear on the ceiling as light reflects on them. Using the wrong technique in a particular space could make the room appear smaller and less cozy.

Now you might be wondering which technique is incorrect. Neither of them is particularly wrong. Yet, in certain situations, one may be a better option. The key is the number of windows available that serve as a source of natural light in the space.

You should only paint the ceiling parallel to the window if the space has one window serving as a natural light source. The general recommendation is to paint the ceiling parallel to the room’s main source of natural light. So, for a one-window room or a room with one window serving as the main source of natural light, we recommend painting parallel to the source of that light.

The reason you need to paint parallel to the single window or main light source is to prevent the appearance of faint shadows from lap marks showing up on the ceiling. Lap marks get created when paint overlays a dry edge. With the right technique, you can reduce the occurrence of lap marks, but it is unlikely you can avoid them completely.

Painting against a main source of light can create lap marks. Light directly hitting the edge of those lap marks will cause shadows. Even with the tiniest lines or ridges, the sun poring across them will highlight the shadows. The shadows may be indistinguishable in a room with multiple natural light sources. Yet, this is less likely to be the case when those lap marks are hit directly by the light from a single window or main light source.

When you or anyone else enters a room, the natural light from the window will make paint lines from a roller obvious if you paint perpendicularly or haphazardly. This effect is aesthetically unpleasing and will appear even worse on a textured ceiling.

Painting parallel or in line with the light from a window or main light source will mask lap mark effects. Thus, in a room with a single window or a single window being the main light source, it will be better to paint in parallel so that the light from the single or main source channels across the lap mark and not against it.

Additionally, painting the ceiling in one direction throughout the process will give an even finish. Painting in whatever way or changing direction mid-process can lead to an awry-looking finish. In this sense, painting in the direction of a single window can give you a straightforward template or guide to achieve an even coat.

On the other hand, you can paint a ceiling perpendicular to a window when multiple windows pour similar levels of light into the room. Parallel painting still works here, but with different windows serving as a light source, there is no way to align with a single one.

Thus, to get the best finish for your ceiling, paint the ceiling perpendicular to the windows when you have more than one window serving as a source of natural light in the room. Here you paint across the longest wall in the room with straight up and down strokes. Alternatively, you can paint in a “W” pattern. The “W” pattern is friendly to newbies.

The reason for painting the ceiling this way is not as long-winded as painting parallel to the window. The simple reason is that multiple light sources counteract the effect of lap marks on the ceiling. So, in painting the ceiling of a room with two or more windows serving as natural light sources, you can paint the ceiling perpendicular to the windows.

How To Paint a Ceiling

Knowing the direction to paint the ceiling is one thing, actually painting it is another. You will see steps for painting a ceiling here. Some of the tools you will need include:

  • Paint
  • Paint tray
  • Plastic tarp
  • Painter’s tape
  • Nap Roller (½ – ¾ inches)
  • Paintbrush (2 to 3 inches)
  • Roller extension
  • Ladder

Once you have these tools, you are ready to paint your ceiling. Below are the instructions.

1) Remove Furniture, Hanging Fixtures, And Equipment

Take out furniture, equipment, hanging fixtures, and all other items that are movable from the room so you don’t accidentally get paint on them.

2) Clean The Ceiling

Remove cobwebs and dust from the ceiling with a broom and possibly sand it afterward. Sanding will help in paint bonding and getting a smooth finish. It would be helpful to clean the surface of the ceiling with some soap if you can. If you spot cracks in your ceiling, it would be best to seal them.

3) Prepare The Area

Cover areas outside the ceiling so paint does not get to them. Use painter’s tape on the edge of the walls you intend to paint. Also, cover the floors and items you could not remove with plastic, cardboard, or towels. If you have painted the walls already, line up the plastic tarp on the side of the walls to protect it from paint splatter. Also, use the tarp if you do not intend to paint the wall.

4) Apply A Good Primer

While this step is sometimes overlooked, we recommend using a primer to cover or block ceiling marks and facilitate stronger paint adhesion. A good primer will also minimize water damage.

5) Cut In

With a ladder, paint the sides of the ceiling first with a brush. Pour a small amount of the paint into a small bucket, put it on the top of the ladder, and paint from it, rather than carrying a heavy paint bucket. Ensure you apply 2 – 3 inches of paint on the edges of the ceiling.

6) Apply The Paint

Attach the roller extension. Afterward, pour a small part of the paint into a paint tray. Then roll it into the tray with your roller. Brush off excess paint from the roller using the textured side of the tray.

It is better to apply a thin coat so the paint adheres to the surface of the ceiling. Roll the paint on the ceiling and move in a parallel motion. Get as close to the brushed areas as you can. We advise using a low nap roller to paint smooth ceilings and ½- to ¾-inch ones on textured surfaces.

7) Let The Paint Dry

Allow the paint to fully dry. You can inspect the ceiling for any areas that need additional work after 30 minutes of drying. Apply a secondary coat, if necessary, but only do this after the first coat is completely dry. Don’t remove the plastic tarp or painter’s tape until the paint has dried.

Ceiling Painting Tips

  • Wear Protective Equipment

Painting the ceiling can lead to paint spilling straight down on you. To protect your eyes wear goggles. Use a cap or cover for your hair, and protective clothing for the rest of your body. You can wear old clothes.

  • Don’t Paint Directly Above Yourself

Do not paint the ceiling directly above you to minimize paint splattering on you. Instead, paint the ceiling ahead of your position on the floor or ladder.

  • Paint The Ceiling First

Paint the ceiling first, if you are painting both the wall and ceiling. This way, you will not have to bother too much about paint spilling on the walls. If paint splatters on the wall, you can cover it when you paint the walls.

  • Clean Tools

Clean up your tools as soon as you finish painting so the paint does not dry on them. It becomes difficult to clean the tools once the paint has dried.


This article discussed whether to paint your ceiling parallel or perpendicular to a window. We also provided some general instructions and tips for painting a ceiling. Painting the ceiling of a space can be challenging. Getting an awry finish after such an arduous task can be disheartening.

When multiple windows serve as natural light sources, you can paint your ceiling perpendicular to those windows. However, if you have just one window or a single window serving as the main source of natural light, we strongly advise that you paint the ceiling parallel to that window to avoid lap marks. This is because light beaming on the side of those marks will cause shadows to appear that will look unpleasant and make the space feel less welcoming.