We reference this product as a separation between aluminum and cement based products (per the building code), a client has asked for a list of recommended manufactureers - does anyone know of manufacturers of this product that can be applied to aluminum?
Does the building code call for this particular product?! or just a separation. I’m wondering where the requirement for this specific lacquer came from.
John - 2010 Edition of FBC 2003.8.4.4:
Aluminum surfaces in contact with lime-mortar, concrete, or other masonry materials, shall be protected with alkali-resistant coatings, such as heavy-bodied bituminous paint or water-white methacrylate lacquer.
John, we prefer to specify bituminous paint, but in some applications bituminous paint is too messy.
John, I researched back to the 2001 Edition of FBC, the same language reappears in each version within the Chapter on Aluminum for sissimilar materials separation.
It’s a Florida thing–the unamended IBC does not have this requirement.
As I’ve said before, Florida Specifications are unique, and South Florida Specifications are insane…but I’ve been writing them for over 30 years and (knock on wood) said specs have never been named in litigation as a cause for negligence, even though we have prepared specs for hundreds of condominium projects - and the insanity continues.
Ron, I am surprised that aluminum corrosion is not addressed as strongly in the IBC as in the FBC, does not aluminum corrode in other parts of the country?
Jerome:
Yes, aluminum does; but the code also doesn’t require a lot of things, like water repellent on exposed masonry, mildew-resistant sealant in wet areas, metal door duty performance, etc. All of these affect building performance and maintainability, but are not regulated by the building code.
Some things are just left for the owner to decide. There is a point in which over-regulation may be reached, which is why many jurisdictions don’t adopt an energy code, or are slow to adopt the IgCC or they make it optional.
I asked because I have usually used other kinds of isolation depending on the condition: peel-and-stick membranes; asphalt building paper; etc. Didn’t happen too often because most of the time I was specifying aluminum with a finish.
iT DEPENDS ON THE THICKNESS OF THE FINISH, AAMA 2605 YES, AAMA 2603 NO, not sure about AAMA 2604 - should be min 0.80 mil thickness to be considered a barrier to corrosion - perhaps someone else can clarify further.
BTW, my previous comment on aluminum finish thickness is from PCA: http://www.cement.org/masonry/cc_al_frames.asp
I’ve asked the FL PPG Coatings rep to look at the PCA article regarding min thickness of paint, and am meeting with him next week. He suggested using urethane sealant as a separation material.
So no one ever answered my original question, Water-White Methacrylate Lacquer manufacturers?
See Page 22 of http://cedecor.com.ar/wp-content/uploads/2011/05/Elvacite_Brochure-06-02.pdf for an example of what’s available. you might want to call the folks who make this available as well - http://www.sigmaaldrich.com/catalog/product/aldrich/474037?lang=en®ion=US
I’m a bit surprised that methacrylate (it’s a form of modified acrylic) is listed as a preferred method of blocking galvanic action. Historically, it wasn’t considered very good for that purpose but with the elimination of zinc chromates and similar coatings due to ecological concerns, perhaps it’s good enough. Resorting to AAMA 2605 just to prevent corrosion due to contact between dissimilar metals might be a little excessive, but it sure does make a good case for defaulting to that option when selecting finishes on aluminum.