Robert:
Yes, you CAN use an elastomeric coating on the exterior of your house,
and if nothing were to damage that coating, it'd last a very long time.
But, that's where the problem is. In a state like Arizona, I expect
that exterior house paints chaulk due to the intense sunlight. And, I'd
be concerned that your elastomeric coating that's 5 times as thick as a
regular exterior latex would chaulk just as quickly as a regular
exterior latex, thereby requiring you to repaint just as often as if
you'd used a regular exterior latex.
So, yes, the coating is 5 times as thick, and so it theoretically should
last 5 times as long, but if it's surface chaulks, then you're not
benefitting from that film thickness cuz you gotta repaint anyhow.
Elastomeric coatings are best suited for masonary or stucco walls with
ACTIVE cracks that would otherwise let rain water or snow melt in
through those cracks, thereby causing damage to the masonary or stucco
if/when that rain or melt water freezes. That is, the person whose
using an elastomeric coating isn't using it cuz it's greater film
thickness means it theoretically should last longer. They're using it
to prevent water from getting into a masonary wall and causing
freeze/thaw damage.
Every paint store sells elastomeric coatings. I'd talk to some of the
paint store managers in your area and find out what their customer's
experiences have been using elastomeric coatings instead of exterior
latex paints.
PS: You don't need to know the rest...
That write up for Behr elastomeric coating said:
> The 100% acrylic latex formula provides a breathable film, releasing
> moisture that builds in walls.
In fact, every latex paint will do that, but some do it better than
others. If you want to know how a paint film can keep rain water from
penetrating through the paint from the outside, but yet still allow
moisture to evaporate through it from the inside, ask and I'll explain
it.
--
nestork