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a (Unregistered Guest) Unregistered guest
| Posted on Thursday, January 17, 2013 - 06:03 pm: | |
A couple questions: 1. Is there a wind-driven rain performance standard for CMU coatings? (A rep suggested TTT 555B federal standard, but I cannot find anything on this.) 2. What ASTM adhesion test standard do you require for HPCs? Differences between ASTM D3359 vs. D4541? |
Richard L Matteo, AIA, CSI, CCS Senior Member Username: rlmat
Post Number: 558 Registered: 10-2003
| Posted on Thursday, January 17, 2013 - 06:58 pm: | |
I would check with The Society for Protective Coatings www.sspc.org |
ken hercenberg Senior Member Username: khercenberg
Post Number: 414 Registered: 12-2006
| Posted on Monday, January 21, 2013 - 01:56 pm: | |
You're possibly looking for Federal Specification FS TT-C-555B. From what I can tell, it's been discontinued. I'm not aware of any apples-to-apples comparison for CMU coatings which is why we deal with coating called elastomeric coatings, cementitious coatings, and high-performance coatings. Is there a difference between them? Depends on what you're trying to accomplish. From trial-and-error, especially error, I find that 'elastomeric' coatings are the lower end group of products typically but not always. Cementitious and HPC can be pretty comparable. Cost of product does not always indicate quality. Adhesion to CMU, or lack thereof, is often not the fault of the coating as much as it can be poor prep (probably the biggest problem), poor detailing (if you're letting water in through another surface, it has to come out somewhere), poor protection of the CMU prior to coating (again, water that got in during construction will come out, sometimes as vapor, afterwards and blow off your coating no matter how good your adhesion testing is), permeability (if your coating is not vapor permeable it will probably fail), use of the wrong CMU (lightweight CMU on exterior surfaces to receive coatings is usually not a good option), and the list goes on. I'd be happy to share specific experiences with specific manufacturers if you'd like. Please let me know how to get in touch with you. |
Richard L Matteo, AIA, CSI, CCS Senior Member Username: rlmat
Post Number: 559 Registered: 10-2003
| Posted on Monday, January 21, 2013 - 02:07 pm: | |
I concur with Ken. |
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