4specs Discussion Forum: What is the difference between Portland cement plaster and Stucco?

20 Feb.,2024

 

Author Message Anonymous
 
Posted on Saturday, May 10, 2008 - 02:50 pm:    and is there such a thing as "Portland cement Stucco"? John Regener, AIA, CCS, CCCA, CSI, SCIP
Senior Member
Username: john_regener

Post Number: 391
Registered: 04-2002
Posted on Saturday, May 10, 2008 - 09:13 pm:    Stucco is the finish coat of a portland cement exterior plaster system. The basecoat (nominal 3/8" thick) is the "scratch" coat. The intermediate coat (nominal 3/8" thick) is the "brown" coat. The finish coat (nominal 1/8" thick) is the "stucco" coat. See ASTM C926 which covers "requirements for the application of full thickness portland cement plaster for exterior (stucco) and interior work." Richard Howard, AIA CSI CCS LEED-AP
Senior Member
Username: rick_howard

Post Number: 179
Registered: 07-2003
Posted on Monday, May 12, 2008 - 09:03 am:    The term "stucco" is often used in a broad sense (erroneously) to indicate finish systems that duplicate the appearance of portland cement plaster, such as EIFS or DEFS (thin-coat sythetic plaster). True stucco is a built-up system as John describes above. While portland cement stucco might be redundant, it does differentiate from the imitators. Anonymous
 
Posted on Monday, May 12, 2008 - 10:25 am:    Several of our clients have asked that we no longer refer to it as Stucco, but rather Portland Cement Plaster citing ASTM C 926 to avoid confusion - semantics, semantics, semantics! Ron Beard CCS
Senior Member
Username: rm_beard_ccs

Post Number: 276
Registered: 10-2002
Posted on Monday, May 12, 2008 - 01:23 pm:    FWISW:

1779: Inventor Bry Higgins receives a patent for concrete stucco.

1824: British stonemason Joseph Aspdin makes kiln-fired mixture of clay and ground limestone on the Isle of Portland, dubbing his creation "portland cement."

Source: May 2008 issue, This Old House Steven Bruneel, AIA, CSI-CDT, LEED-AP
Senior Member
Username: redseca2

Post Number: 106
Registered: 12-2006
Posted on Monday, May 12, 2008 - 02:07 pm:    In reference to a brown, scratch and topcoat assembly, we provide a definition that "the work of this Section may be referred to as Stucco", just to close the loop and avoid tiresome RFI's.

In other Sections we have a similar comment regarding "curtainwall" and "windowall" in reference to aluminum framed glass and panel systems. I have heard each used in a single sentence in a trailer meeting, by the manufacturer's rep no less, so I might as well give up.

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