| Author |
Message |
Brett Wilbur
Junior Member
Username: bwilbur64
Post Number: 2
Registered: 02-2018
| | Posted on Wednesday, February 28, 2018 - 02:10 pm: |    |
Searched the archives but I don't see anything about this product - "one-coat plaster" touted as the “the most efficient stucco system available.” OK, fine, so says the NOCSA. http://nocsa.org/index.html.
It is perhaps a misnomer. Yes, it is a single base coat, but still has a finish coat, so for all intents and purposes, it is a two-coat system. The metal-lath-reinforced cement base coat takes the place of, or combines, the typical scratch and brown coats, but still, it has a finish coat. Also, glass fibers are embedded into the base coat so it offers higher flexural strength, reduced labor costs, low maintenance, high durability.
So my question is, anybody ever use this product/system? What is your experience? I have a GC that wants to VE a standard 3-coat system.
On the surface, it sounds like a good idea, but I don't know enough about the science of plaster to even know why we use 3-coat systems. Can anyone school me?
I might feel more comfortable if it was on a solid backup like CMU or concrete, but it will be on glass-mat sheathing and metal stud framing. |
Liz O'Sullivan
Senior Member
Username: liz_osullivan
Post Number: 241
Registered: 10-2011
| | Posted on Wednesday, February 28, 2018 - 02:27 pm: | |
The building code may not allow the use of this type of stucco system for your building, depending on what the construction type is and the exact one-coat stucco assembly. If I recall correctly, usually it's allowable for Type V construction, if there's no continuous insulation within the stucco assembly (and sometimes ok if there is insulation as part of the assembly). Different manufacturers have different ICC-ES reports that say different things for similar one-coat stucco assemblies, so whether it's ok or not could be manufacturer-dependent, too. Consider talking to the technical hotline for the one-coat stucco manufacturer, or a rep. |
Nathan Woods, CSI, CCCA, LEED AP
Senior Member
Username: nwoods
Post Number: 735
Registered: 08-2005
| | Posted on Wednesday, February 28, 2018 - 02:36 pm: | |
one coat plaster systems are extremely popular in the southwest, such as Arizona, where the base layer is usually 1" of EPS foam. Its basically a modified EFIS approach. The systems I am familiar with are all proprietary, and have their own ICC-ES reports. A gotcha with a lot of those systems is that they are tested on 2 story buildings, and thus their test data is insufficient for use on 3 story multifamily projects where the majority of Arizona housing developers want to use 1 coat. Also, having foam as a base coat, the finish is very susceptible to impact damage, so I would not recommend in stairs, corridors, etc.... |
Wayne Yancey
Senior Member
Username: wayne_yancey
Post Number: 857
Registered: 01-2008
| | Posted on Wednesday, February 28, 2018 - 02:43 pm: | |
Keep in mind where the project is located.
Is the rain fall less that 20 inches per year?
Is the sheathing glass mat gypsum board, plywood or OSB (Danger, danger, Will Robinson)?
Is the project 2 storeys or less?
Don't install interior vapor barriers. |
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