The Complete Guide to Painting Over Flat Paint

If you have a room in your house painted with flat paint, you may wonder if you can paint over it with a new color and sheen. 

Painting over flat paint takes some preparation. Despite not having a glossy finish, sanding is required. This will create a good base for the new paint and ensure it properly bonds to the old surface. Afterward, use a primer to cover imperfections and make it easier for your top coat of paint to adhere. 

In this article, you will learn:

  • What kind of paint you can use over flat paint
  • What you need to know about sanding
  • What you need to know about priming
  • How to paint over flat paint

What Kind of Paint Can You Use Over Flat?

Paint Finishes

Once the surface has been prepped, you can choose from various paint finishes. One option is eggshell, which offers a slight shine and is easy to clean.

A satin finish is another option, providing more shine than eggshell. This finish is also more durable and easier to clean than eggshell. 

Semi-gloss paint is a good choice for those looking for even more shine. This finish is commonly used in kitchens and bathrooms due to its excellent moisture resistance.

Finally, there is high gloss, a finish that provides the highest level of shine available. This type of finish is ideal for trim, doors, and other areas requiring extra glossiness.

In summary, you can apply any paint finish over flat paint, such as matte, eggshell, satin, semi-gloss, or high-gloss. These finishes provide a different sheen and level of durability, allowing you to achieve the desired aesthetic and functionality for your space.

Paint Types

Oil-Based Paints

Oil-based paints are paints that use oil as a binder. They are usually made of natural oils such as linseed oil or synthetic alkyds. These paints provide a hard, glossy finish and are typically used for painting surfaces such as wood, metal, drywall, and other surfaces.


  • Oil-based paints create a hard, glossy, more durable finish than water-based paint finishes. This makes them ideal for high-traffic areas and surfaces that require frequent cleaning.
  • The glossy finish of oil-based paint makes it easy to clean with just soap and water.
  • Oil-based paints last longer than water-based paints because they don’t fade or chip easily over time.


  • Oil-based paints have a strong odor when wet, which can be unpleasant to work with and may require ventilation in enclosed spaces.
  • Cleaning up after using oil-based paint can be messy since it requires mineral spirits or paint thinners to remove from brushes and rollers instead of just soap and water.
  • Oil-based paints take longer to dry than water-based products, which can cause project delays if not accounted for in the planning stages.

Water-based (Latex) Paints

Water-based paints are a type of paint that uses water as the main solvent instead of chemical solvents. They are also known as latex paints, consisting of a pigment and a binder with water used as a carrier. Water-based paint is more advantageous than oil-based paint for many reasons.


  • Water-based paints are easier to clean since they can be washed away with soap and water.
  • They dry quickly, making them ideal for painting projects that need to be completed in a short amount of time.
  • They emit fewer VOCs (volatile organic compounds) than oil-based paints, making them more environmentally friendly.
  • They’re available in a wide variety of colors, so you can find the perfect shade for your project.


  • Water-based paints are not as durable as oil-based paints, so they may need to be reapplied more often if exposed to harsh elements like rain or sun exposure over time.
  • They may not adhere well to surfaces previously painted with oil-based paint, so it’s important to properly prepare the surface before applying the new coat of paint.

Using Water-Based Paint over Oil-Based Paint

Painting over oil-based paint with water-based paint can be a tricky process, but it is possible with proper preparation and technique. Before you begin, there are a few factors that you should consider to ensure compatibility between the two types of paints.

Firstly, ensure the oil-based paint is dry and cured for at least 24 hours before attempting to paint over it. This will prevent the new paint from peeling or cracking.

Secondly, consider the age and condition of the oil-based paint. If the paint is old or in poor condition, it may not be suitable for painting over with water-based paint.

Clean the surface thoroughly to remove dirt, dust, grime, or grease. Use warm water and soap, then rinse well and let the surface dry completely. Using fine-grit sandpaper, sand the surface.

Apply a high-quality primer that is specifically designed for painting over oil-based paint. This will help the new paint adhere to the old paint and prevent peeling or cracking. Follow the manufacturer’s instructions for application and drying time.

Once the primer has dried completely, you can apply the water-based paint. Use a high-quality paintbrush or roller and apply the paint in thin, even coats.

Allow each coat to dry completely before applying the next coat. You may need to apply multiple coats depending on the color and coverage.

It’s important to take safety precautions when painting, so wear gloves, eye protection, and a mask to avoid inhaling fumes. Additionally, make sure that the room is well-ventilated throughout the painting process.

Priming Flat Paint Before Painting: What You Need to Know

A primer is a coating applied to surfaces before the paint to ensure that the surface is suitable for painting.

It is designed to provide a smooth, even surface for the paint to adhere to, and as such, it helps to reduce the number of coats of paint required, saving you time and money. Primers also help to block stains, enhance the paint’s color, and increase the paint’s durability.

Primer works exceptionally well on flat-painted surfaces because it creates a smooth, uniform surface that primes the surface for a new coat of paint.

When applying primer, use a brush or roller to cover the surface evenly and apply a thin coat. During this process, you will notice that primer has a dull finish, which will not affect the final painted surface.

Types of Primers

Choosing the right type of primer is essential to ensure that your paint job lasts long and looks beautiful. Here are the three main types of primer that can be used to paint over flat paint:

Oil-based Primer

Oil-based primers are known for their excellent adhesion and stain-blocking properties. These primers cover stains and odors, especially on wood surfaces.

Moreover, they are highly resistant to water and mold, making them ideal for use in humid areas like bathrooms and kitchens. However, they have a strong odor, take longer to dry, and can be yellow over time.

Latex or Water-based Primer

Water-based primers, also called latex primers, are popular due to their versatility and easy cleanup. They dry faster than oil-based primers, are low in odor, and can be used on various surfaces, including wood, metal, and drywall.

They are eco-friendly and can be cleaned up easily with soap and water. However, they are less effective in covering stains and water than oil-based primers.

Shellac Primer

Shellac primer is made from natural materials and is perfect for blocking any stains, including nicotine stains. It’s also great for covering knots or other discolorations on wood surfaces.

They dry up quickly, so you can apply the paint on top of it quickly. However, it can be difficult to clean up due to its alcohol base, so it’s best to use gloves and work in a well-ventilated area.

Tips for Choosing the Right Primer and Applying It Properly

When selecting the right primer for a painting job, consider the type of paint you’ll be using. For example, choose an oil-based primer to ensure proper adhesion and coverage if you’re using oil-based paint. With latex paints, a latex or water-based primer is best to use.

Before choosing a primer, consider the surface you’ll be painting. Different surfaces require different types of primer. For example, if you’re priming bare wood, you’ll need a wood primer.

Once you’ve chosen your primer, you need to prepare the surface. Sand away rough patches and fill in cracks or holes with a wood filler. If there are previously painted surfaces, ensure they’re clean and free of grease and wax before applying the primer.

Before applying any primer, it’s essential to prepare your surface properly. Remove any dirt, dust, or grease by washing the surface with soap and water or using a degreaser if necessary. If painting a previously painted surface, ensure the paint is not chipping or peeling away before applying the primer.

To apply primer properly, you should use a paintbrush or roller, depending on your painting surface. Make sure to apply the primer evenly and not too thick, as this can result in brush marks or drips.

If using a roller, roll in one direction, and use a criss-cross pattern to distribute the primer evenly. It’s important to let the primer dry before applying paint over it. 

Check the manufacturer’s instructions for the recommended drying time, which typically ranges from 30 minutes to a few hours.

Sanding Flat Paint Before Painting: What You Need to Know

What Sandpaper to Use for Sanding Flat Paint?

The type of sandpaper you use depends on how much prep work you’re doing. For basic prep, medium-grit sandpaper should be sufficient. This may include removing any loose paint or smoothing out a rough surface.

Then fine, grit sandpaper should be used for a smoother finish. The grit number should range from 150 to 220. A finer grit will reduce the risk of leaving scratches on your surface.

How Much Do You Need to Sand Flat Before Painting?

If you’re refinishing a surface, you’ll want to sand it until the flat paint is completely smooth. Depending on the condition of your walls, this could take anywhere from 30 minutes to an hour.

Can You Paint Over Flat Without Sanding?

Before painting over flat paint without sanding, weighing the advantages and disadvantages is important.


  • Painting over flat without sanding is quicker and easier than sanding.
  • You won’t risk damaging the walls by sanding too hard or using coarse grit.
  • There’s no dust or mess to clean up afterward.


  • If the paint is old or unevenly applied, you won’t be able to fix any imperfections without sanding.
  • You may have a rough finish if you don’t prepare the surface properly.

Other Options for Painting Over Flat Paint

Sanding is often a go-to option for preparing the surface. However, sanding can be time-consuming and messy, not to mention it creates dust that can be harmful when inhaled. 

Luckily, there are other options available that can achieve the same results without the hassle of sanding.

One option is using a liquid deglosser. Liquid deglossers break down the paint’s surface, making it easier to remove or adhere to.

Simply apply the deglosser to the surface and let it sit for a few minutes before wiping it away with a cloth. Make sure to follow the instructions on the product carefully and work in a well-ventilated area.

Another option is using a paint stripper. Paint strippers work by chemically breaking down the paint, making removing it easier.

Like with liquid deglossers, follow the instructions carefully and work in a well-ventilated area. Remember that some paint strippers can be harsh and may damage surfaces, so always test a small area first.

Once the surface is deglossed or the paint has been removed, you can paint over the flat paint.

How to Paint Over Flat Paint

Tools and Materials

Step 1: Clean the Walls 

This is vital to ensure the perfect finish of your new coat of paint. Cleaning the walls is necessary to remove dirt and grime, which could result in uneven application.

Warm water and mild soap or detergent are the best way to clean your walls. Use a sponge to scrub gently in a circular motion. Rinse with clean water, and allow to dry fully.

Inspect the walls for any areas with mildew, and treat them before proceeding. Also, check for any areas that need to be repaired. Use a patching compound to fix damaged sections, and let them dry before painting.

Step 2: Sand the Surface

Sanding a previously painted surface is an inexpensive and effective way to prepare it for a fresh coat of paint. The process of sanding helps to roughen the surface, creating a rough texture that allows the paint to better adhere to it.

Sand the surface by moving the sandpaper in a circular motion or the direction of the grain.  To avoid over-sanding, use a light touch and monitor the progress.

If the surface is smooth, don’t sand too much, as this can remove too much paint. If you encounter rough patches requiring more attention, circle back and sand those areas again.

Step 3: Apply Primer

Once the flat paint is clean and smooth, you can apply a primer coat. Primer works to fill in any tiny dents or cracks that may exist in the paint’s surface, providing a layer of protection against potential problems with adhesion.

I recommend Zinsser’s B-I-N Primer-Sealer, specifically designed to promote the adhesion of new paint to old surfaces. It is also a great way to ensure a uniform finish and good coverage with your new layer of paint.

Do not skip this step. It will make sure your paint job is successful and long-lasting, so it’s worth taking the time to do it properly.

Step 4: Apply the Paint

After the primer has dried, it’s time to paint. Choose the color of your choice, and apply it with a brush or roller. Repeat the process with thin layers for perfect coverage. For the best finish, you could apply two coats of paint.

Make sure you allow for enough drying time between the coats. Similarly, gently run your fingers over the surface to check for imperfections after the paint has dried up. Where necessary, perform touch-ups.

Step 5: Clean up 

After completing the painting, you could have some leftover paint, tools, or brushes. Ensure that you clean them properly so they last longer.

Clean your brushes with soap and water, or if it’s an oil-based paint, clean them with mineral spirits. Proper cleaning of tools will make them last longer and save you the cost of replacing them regularly.

Joshua Milton

Joshua Milton is a passionate DIY and home improvement enthusiast. With his expertise in various projects, he provides practical tips, step-by-step guides, and creative ideas for transforming your living space.

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