Green tin roofs

Additive for altering sheen of roof coating

Green tints have been a challenge to roof coating manufacturers since the 1990s.    Water-based formulas for roof coatings, such as acrylic, require the addition of zinc to retard the growth of organic “stuff” in the finished product.  Since green tints, used to changed the generic acrylic to green, are usually organic, the zinc addition tends to cause a chalking action.  The result:  in five to 8 years, the roof appears worn and aged.

The irony of the aging green acrylic-coated roofs:  the performance is the same as any other colored acrylic….it just that the roof does not look pleasing.

Recent improvements in green roof coating

Recently, materials have come available to resolve the early chalking that characterizes acrylic green coatings.  Several versions are on the market that offer a customer a more attractive appearance long-term.

As with any modification, there are tradeoffs:

For example, the application of a cyclo-aliphatic urethane product is tricky–certainly not recommended for the do-it-yourselfer.

The acrylic products are easy to apply, easy to repair, easy to touch up and reasonably priced.  The roof below with the non-chalking cyclo-aliphatic urethane is attractive to the eye, yet a contractor has to take other steps to compensate for its limitations, such as  our project in Washington, DC

For example, the above photo illustrate the messy mixing requirements.

View of roof with Restoration Green