Cementitious Coatings over Foam | Ask Mason Knowles - SPF Consultant | Spray Foam Technical Questions and Answers | SprayFoam Magazine Q&A Forums

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Posted: Dec 11, 2010 10:33 PM	Cementitious Coatings over Foam Hi Mason I just finished another exterior project with closed cell foam where we used cementitious coatings to cover the product as an expierement. Do you have any experience with this type of coating? Do you know if any testing has ever been done using cementitious coatings as a roof coating? This material is very common in the construction industry and in different forms is used as a fluid applied air barrier, vapor barrier, dry wall, etc.... How will it stand up as a Thermal or Ignition Barrier? I was just impressed with the strength of the product, the overall look of the product, colors available to me and most importantly the ease of application using the same equipment that I alread have. What are your thoughts?
mason Posted: Dec 12, 2010 11:51 AM	I am familiar with a brand of cementitious coating that was developed for foam roofing by Industrial Plastics out of Houston. The coating was an acyrlic, cement blend that was installed with a pole gun and looked like stucco. It had great fire resistance and a few drawbacks. Because it does not have good elasticity the coating will crack and it tends to break off in small chunks. You need to check out it every year and patch in the areas that break. I have seen roofs more than 25 years old with the coating in fairly good shape and seen others that broke completely apart. For my money, I would prefer an agregate covering in lieu of the cementitious coating similar to what NCFI markets.

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Posted: Dec 11, 2010 10:33 PM

Cementitious Coatings over Foam

Hi Mason

I just finished another exterior project with closed cell foam where we used cementitious coatings to cover the product as an expierement.

Do you have any experience with this type of coating?

Do you know if any testing has ever been done using cementitious coatings as a roof coating?

This material is very common in the construction industry and in different forms is used as a fluid applied air barrier, vapor barrier, dry wall, etc.... How will it stand up as a Thermal or Ignition Barrier?

I was just impressed with the strength of the product, the overall look of the product, colors available to me and most importantly the ease of application using the same equipment that I alread have.

What are your thoughts?

mason

Posted: Dec 12, 2010 11:51 AM

I am familiar with a brand of cementitious coating that was developed for foam roofing by Industrial Plastics out of Houston. The coating was an acyrlic, cement blend that was installed with a pole gun and looked like stucco.

It had great fire resistance and a few drawbacks.

Because it does not have good elasticity the coating will crack and it tends to break off in small chunks. You need to check out it every year and patch in the areas that break.

I have seen roofs more than 25 years old with the coating in fairly good shape and seen others that broke completely apart.

For my money, I would prefer an agregate covering in lieu of the cementitious coating similar to what NCFI markets.

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