Good day, Lettie.

We have a new flat roof with no attic, just a 200 sq. m. space with thin PE (polyethylene) foam insulation. The contractor installed pre-painted dark metal roofing instead of white.

My concerns are adhesion, lifespan, and measured reduction of heat under the sun. Any advice in terms of paint I can use will be appreciated.

Boysen User J

Hi, Boysen User J!

When you don’t have enough measures in place against the heat, it really can get hot, pretty quickly indoors during the summer season in the Philippines.

Taking your concerns into consideration, I would suggest seeking the help of Boysen Cool Shades, a heat-reflecting roof paint. Boysen Cool Shades is a water-based, low-VOC, heat-reflective roof coating. Its all-acrylic binder makes it reliably durable and long-lasting so you don’t have to worry about adhesion and lifespan. It will stick by you whatever the weather.

And, yes, Cool Shades can lower the heat inside your home as well. It does this by utilizing infrared-reflecting (IR) pigments. The IR pigments bounce back light hitting your roof before it can turn into heat that’s absorbed by your house. This then reduces heat build-up resulting in a cooler home.

Boysen Cool Shades was tested by the Department of Science and Technology (DOST). Results showed an up to 15ºC decrease in surface temperature on sample materials with Cool Shades versus conventional roof coating.

Paint TechTalk with Lettie: What Roof Paint Should I Use? | MyBoysen

Here’s how to apply Boysen Cool Shades on your roof:

Surface Preparation

For recoating pre-painted galvanized surfaces in good condition, simply sand lightly then wipe the surface clean with a rag. Sanding will ensure better adhesion of your new coat of paint.


Now that you’ve prepped the surface, prime it with Boysen Primeguard. Wait for 2 hours to allow it to completely dry. Then, apply 2 coats of Boysen Cool Shades. Recoat interval is 2 hours. For the best cooling effect, choose Cool Shades in the color Reflecting White.

Now, you’re all set. Congratulations on the new roof and happy painting!

Your Painting Partner,

Need advice? Paint TechTalk with Lettie is here for you. Comment your painting question below or send an email to


Jill is a writer on a continuous journey to learn about paint and share them with you, the reader. She has an interest in the technical side of things but also thoroughly enjoys playing with colors. She likes calm greens, quiet blues, and mellow yellows best.


  1. hi let!

    What kind of paint should i use with our rusting (not damaged i assumed and no holes) long span roof and how to repaint it? our long span roof is almost 15 years old, never been repainted since installation.

    hope you can guide me on this.

    Thank you!

    • Please see below for the suggested system.

      For recoating pre-painted galvanized surfaces in good condition, sand lightly then wipe the surface with a clean rag before applying paint. Remove all loose paint film to sound surface. Spot prime bare substrate.

      For corroded galvanized surfaces, remove rust by wire brushing and use BOYSEN Metal Etching Solution B- 71. Let it stay for 10 – 15 minutes. Be sure to remove all remaining residue. Immediately prime after drying.

      Primer (for exposed metal only): BOYSEN Rust-Off or BOYSEN Red Oxide Metal Primer
      Top coat: BOYSEN Roofgard or BOYSEN Cool Shades (at least 2 coats of any desired color)

      Please refer to the links below for product details and colors available:
      • BOYSEN Roofgard:
      • BOYSEN Cool Shades:

      If you have more questions, please directly answer the email sent to you last May 31.

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