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Message |
Ronald J. Ray, RA, CCS, CCCA, CSI, SCIP, AIA
Senior Member
Username: rjray
Post Number: 188
Registered: 04-2004
| | Posted on Thursday, November 15, 2018 - 11:36 am: |    |
Folks,
I spoke with someone at ICC regarding any required flame spread or smoke-developed index for PVC drywall trim, specifically related to a "new" product that can be as much as 3.5 inches high above the floor.
The gentleman at ICC was of the opinion that "trim" is "trim" and that drywall trim must comply with IBC 806.7 (Class C when tested in accordance with ASTM E84.)
Of course, drywall trim does not come in the test sample size required by ASTM E84 (20 to 24 inches wide and 24 feet long), but that did not seem to be of any concern to the gentleman with ICC.
I could only fine one manufacture of PVC drywall trim that listed ASTM E84 testing. They told me they had no idea why they included that information, and would not have any test reports to support the data.
Thoughts? |
Ronald L. Geren, FCSI Lifetime Member, AIA, CCS, CCCA, CSC, SCIP
Senior Member
Username: specman
Post Number: 1521
Registered: 03-2003
| | Posted on Thursday, November 15, 2018 - 01:10 pm: | |
PVC will have inherent properties regardless of who manufactures the product, provide the material complies with ASTM D1784. Here's a link to the Vinyl Institute's document on fire properties of PVC: http://www.vinylinfo.org/sites/default/files/Fire%20Properties%20of%20Polyvinyl%20Chloride.pdf
Rigid PVC will have a flame spread index (FSI) less than 25, so it would be considered a Class A finish. Materials with low FSIs will generally have low smoke developed indices (SDI).
I looked to see if ASTM D3678, Standard Specification for Rigid Poly(Vinyl Chloride) (PVC) Interior-Profile Extrusions, includes the ASTM E84 test, but it does not.
Just think, we put PVC on the roofs of buildings (which is flexible and has a lower FSI) without much of an issue (even though roofing is tested differently), so it would reason that the rigid trim for gypsum board would have an equal or better performance than roofing.
Ron Geren, FCSI Lifetime Member, AIA, CCS, CCCA, CSC, SCIP
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John Bunzick, CCS, CCCA, LEED AP
Senior Member
Username: bunzick
Post Number: 1771
Registered: 03-2002
| | Posted on Thursday, November 15, 2018 - 04:22 pm: | |
Ron, are you referring to the drywall accessories, such as corner bead? I never heard of that being considered trim. Seems odd. |
Ronald J. Ray, RA, CCS, CCCA, CSI, SCIP, AIA
Senior Member
Username: rjray
Post Number: 189
Registered: 04-2004
| | Posted on Thursday, November 15, 2018 - 05:26 pm: | |
Hi John.
My interest was in a specific product, but the ICC guy did not think it made any difference if it was PVC drywall corner bead or any other type of PVC drywall “trim.”
Based on Ron Geren’s statements, I can’t help but wonder if someone else had answered the ICC telephone, I would have received a different opinion.
Per ASTM C1047, PVC trim must comply with ASTM D3678, Class II or III, which requires PVC extrusions to comply with ASTM D1784, the standard Ron referenced. ASTM D1784's reference test for flammability is ASTM D635, not ASTM E84.
However, based on the link Ron provided, it appears that rigid PVC of any size or profile would meet the requirements if IBC 806.7, whether or not required for gypsum board PVC accessories. |
Guest (Unregistered Guest)
Unregistered guest
| | Posted on Thursday, November 15, 2018 - 07:44 pm: | |
I think an argument could be made for corner bead not being "...decorative or protective...", i.e., nothing like/similar to moldings, chair rails, baseboards, etc. as examples cited in IBC? Corner bead is neither "interior...finish" as it is not exposed per Chp 2 definitions for "interior wall and ceiling finish"?
I think your "mistake" is calling it "trim"; correct nomenclature is "corner bead"...embedded in wall assembly...and not a surface-applied decoration? |
Ronald L. Geren, FCSI Lifetime Member, AIA, CCS, CCCA, CSC, SCIP
Senior Member
Username: specman
Post Number: 1522
Registered: 03-2003
| | Posted on Monday, November 19, 2018 - 10:36 am: | |
Corner bead is "protective"--it protects the external corner of a gypsum board wall from damage and is specifically mentioned in ASTM C840, "external corners shall be protected with a metal corner bead or other suitable type of corner protection..."
As for not calling it trim, well, ASTM C840 refers to metal and PVC accessories (including corner bead) as "trim and casings."
Although corner bead is covered by a coating of joint compound, some PVC accessories are exposed.
I understand that ICC's response is an opinion and not an official committee interpretation, and the response from another staff member may have resulted in a different opinion. Calling corner bead "trim" by IBC definition is splitting hairs, but the fact remains, whether "trim" or not, the material complies with IBC's requirements for "trim."
Ron Geren, FCSI Lifetime Member, AIA, CCS, CCCA, CSC, SCIP
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