Painting Spray Foam (Expanding Foam) Insulation: Bet You Didn’t Know This!

Now that you’ve successfully installed spray foam insulation in your home you wonder how to camouflage the places where the dried insulation is visible. What you haven’t realized was that spray foam insulation has a distinctive color, and because of this, exposed insulated areas often form an unwanted focal point in a room. 

You most probably have wondered whether you can paint over the insulation to let it blend in with the color of your walls or ceiling. So can you paint spray foam insulation?

You can definitely paint over dry spray foam insulation. You can paint over the insulation whether it is outside or indoors. It is not necessary to paint spray foam insulation, but if you paint exposed areas of insulation to look better, it will have no negative effect on the insulation. You just have to use the right type of paint and method of applying.

In this article, we’ll have a brief look at what is spray foam insulation exactly and what type of paint do you have to use if you want to paint it. Then we’ll discuss the steps you should follow to successfully paint the insulation, and look at different methods of applying the paint.

paint spray foam insulation

What is spray foam insulation?

Spray polyurethane foam (SPF) is a spray-applied plastic and is a very effective insulation and air barrier material. You can use it to seal walls, floors, and ceiling cavities to prevent air and heat movement. It is widely used to insulate buildings and seal cracks and gaps to make buildings, including homes, more energy-efficient. It can also be done by a DIY enthusiast.

It is often used to seal spaces around electrical outlets and light fixtures, and where windows and doors meet the walls. Spray foam insulation can be sprayed into an open cavity in new or existing constructions and it will never lose its shape, compress, or sag over time.

Why paint the spray foam insulation?

Spray foam insulation doesn’t need any paint to enhance its effectiveness, but if you paint over it, it will have no negative influence on the insulation capabilities of the spray foam. 

But why do people then sometimes paint on spray foam insulation? 

Spray foam insulation has a quite distinct light yellow-beige color that homeowners sometimes might want to hide. The best way to hide it is to paint over the visible insulation sections. You can paint it any color you want to.  

Painting is generally the more cost-effective way of “camouflaging” the spray foam insulation that you don’t want to attract attention to.  

Another alternative could be the fitting of extra drywall sections. You can even decide not to insulate the areas where the spray foam insulation will be visible. 

How to paint spray foam insulation

If you follow the steps we will explain here, you will find it easy to paint the “unattractive” spray foam insulation in your home. Before you start reading, I recommend watching the video below;

Step 1 – Wait for the foam to dry

Wait until the foam has dried and settled. When it is dry it will be hard and stable. It takes at least 30 minutes for the spray foam to expand and start to settle. It will also start to dry after about half an hour. 

Although the foam may feel dry after 30 minutes, it is only the surface that has become dry by then.  To get fully set and dry overall will take at least 8 hours. But it is good practice to wait 24 hours before you start to manipulate the hardened foam and start painting.  

Step 2 – Manipulate the foam insulation

The visible areas of the insulation will mostly look rough and the edges might be uneven. To make it more acceptable to be in view and to start preparing the foam for painting, it is now time to cut and sand the areas and edges.  

For safety and health reasons, you should wear personal protective wear such as a mask and goggles when cutting and sanding the foam. Always cut away from your body. 

 You can use a butter knife or utility knife to trim or cut the foam insulation. If it is a thick section you want to cut off, it is better to use a small handsaw and then do the finer trimming with a knife. Try to cut as near to the surface as possible and use smooth strokes when cutting. 

When you’ve cut off everything you want to get rid of, use sandpaper for the final touches. Ensure that you don’t remove foam under the surface when you are sanding the area.

Step 3 – Clean up all dust and debris

Cutting and sanding always leave a lot of dust and even some debris on the surface. You can’t paint over dust and debris and therefore you have to clean the area you want to paint thoroughly. 

You can wipe the surface down with a damp cloth if it is waterproof spray foam that has been used. Otherwise use a dry cloth to remove the dust.  If possible, it is good to either blow the dust and debris away with pressurized air or suck it in with a vacuum cleaner. 

Remember to wear your mask and goggles so that dust and debris can’t be inhaled or get into your eyes. 

Step 4 – Decide on the paint you are going to use and how to apply it 

Type of paint

The specific type of paint will differ depending on whether you are going to use it outdoors or indoors. Paint for exterior use should be much more durable for changing weather conditions than paint to be used only inside the home.  

There are different brands of paint that you can use, but it is recommended that you only use latex or water-based acrylic paint for your painting.  Do not use any oil-based or solvent paint as it will break down the foam and destroy it over time. 

Another tip is not to use glossy paint. Glossy paint might emphasize the insulation patch that you want to camouflage. 

Application method

When you’ve decided on the paint you are going to use, you have to decide on the application method. Let’s look at some of the methods:

  • Hand brushing 

Hand brushing is ideal for small detailed paintwork and for hard-to-reach places but is not recommended for large areas.  It is very difficult to get an even and smooth surface with a hand brush.

  • Paint rolling

Paint rolling is a good choice for larger areas that have to be painted if you don’t want to go the aerosol way.  The problem with paint rolling is that it shows unevenness in the material. Thus, the surface of the foam insulation has to be very smooth to successfully paint it with a roller. 

  • Spray painting

Spray painting is in most cases the ideal way to paint the visible parts of your spray foam insulation. You get a smooth surface effect when you spray-paint. For small jobs, you can use spray paint in an aerosol can, but it might be worthwhile to get a spray gun if you have to paint large areas.

Step 5 – Apply the first coat of paint

For the best results paint should be applied in multiple lights and even coats, but the first coat will always set the foundation of all the other coats, and ultimately the final look.  The more time you take with the first coat, the easier the application of the following coats will be.

You must also have the patience to wait for the first coat (and every coat thereafter as well) to dry thoroughly.  It is recommended that you give the first coat at least 5 hours to dry before you paint the second coat. 

Good ventilation in the area where you are painting and warm, dry weather conditions can shorten the drying period of the first coat. But it will still be a good idea to wait at least 5 hours. 

Step 6 – Final coats of paint to complete the project

For the sake of good appearance and durability, it is necessary to apply more than one coat on the spray foam insulation. Multiple coats help to seal the material, especially if it is outdoors.

It is recommended that you apply at least 2 to 3 coats of latex or water-based acrylic paint.

It is important that the second coat is applied exactly as the first coat – the same paint, the same thickness, and the same method of applying. Further coats can be thicker, and if needed be applied even with another method. 

If you want to, you can finish everything off with a coat of varnish. 

FAQs

Q: Is Great Stuff spray foam paintable?

A: When Great Stuff spray foam has hardened and cured sufficiently, you can paint it any color you want.  The paint will also prevent the foam from discoloring under UV light.

Q: Can you use Rustoleum spray paint on spray foam insulation?

A: Rustoleum spray is an acrylic spray paint and is safe to use on spray foam insulation.  It can be used for interior and exterior surfaces. 

Conclusion

Although it is not necessary to paint spray foam insulation, you can paint it, especially in visible areas. To cover the yellow-greyish color of the dry insulation, many homeowners paint the visible areas another color to make it less of an “ugly” focal point in a room.  

Just use the correct type of paint and procedures and you can blend the previous  “ugly” parts of the insulation into your color scheme in the room without influencing the insulation capabilities of the spray foam. 

Charles John

Experienced HVAC technician with 8 years of experience in the industry. Capable of handling all sorts of heating and cooling equipment as well as proficient in operational management, construction-related techniques such as preventative maintenance, electrical troubleshooting and AutoCAD

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