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David J. Wyatt, CDT
Senior Member
Username: david_j_wyatt_cdt

Post Number: 326
Registered: 03-2011
Posted on Wednesday, June 24, 2020 - 10:03 am:   Edit PostDelete PostPrint Post

Good morning.

I have been asked to specify "Very High-Impact" gypsum board for interior partitions for a church renovation project. "Very High-Impact" seems to be a marketing term, rather than an industry consensus term. ASTM C1629 classifies levels of performance, but does not appear to ascribe descriptive terms like that. Does anyone have any advice on this? Thank you.
Gail Ann J. Goldstead, AIA, CSI, CDT, LEED AP, BD+C
Senior Member
Username: ggoldstead

Post Number: 27
Registered: 03-2015


Posted on Wednesday, June 24, 2020 - 10:18 am:   Edit PostDelete PostPrint Post

David,
I agree with you. The Gypsum Association references ASTM C1629 as well:
https://gypsum.org/commercial-applications/impact-resistant-gypsum-panels/
GP Dens Armor Plus also references ASTM C1629.
Gail Goldstead
Dave Metzger
Senior Member
Username: davemetzger

Post Number: 771
Registered: 07-2001
Posted on Wednesday, June 24, 2020 - 10:31 am:   Edit PostDelete PostPrint Post

David:

Can the client advise where these partitions are, and what kinds of impacts they are concerned about? Not in terms of foot-pounds of course (because they likely wouldn't have a clue), but eg. wheeled carts in a dock area? storage room for chairs and tables?

That could at least point you in the right direction to specify the appropriate level of performance.
J. Peter Jordan
Senior Member
Username: jpjordan

Post Number: 1131
Registered: 05-2004
Posted on Wednesday, June 24, 2020 - 10:32 am:   Edit PostDelete PostPrint Post

What is important is the type of abuse that you want to protect against. Abrasion resistance requires a different approach than impact (or what I like to call "punch thru").

I believe that the best solution for this is to use some sort of fiber cement board that can be finished like gypsum board. Use 1/4- or 3/8-inch thick over regular gypsum board (or Type X). This should be very good against abrasion and provide enhanced impact resistance.

Unfortunately, the gypsum board industry has sold owners and designers on the idea that a paper face product can be effective against abuse. I maintain that if you have a bunch of high school kids with loaded backpacks crammed into a space, you will have a high level of abuse, even if most of it is unintended.
J. Peter Jordan, FCSI, AIA, CCS, LEED AP, SCIP
Edward J Dueppen, RA, CSI, CCS, LEED AP
Senior Member
Username: edueppen

Post Number: 63
Registered: 08-2013
Posted on Wednesday, June 24, 2020 - 11:00 am:   Edit PostDelete PostPrint Post

For "punch-thru" resistance, I suggest you consider applying a layer of 1/2" or 3/4" plywood behind any type of drywall. We use this in behavioral health projects.
David J. Wyatt, CDT
Senior Member
Username: david_j_wyatt_cdt

Post Number: 328
Registered: 03-2011
Posted on Wednesday, June 24, 2020 - 11:45 am:   Edit PostDelete PostPrint Post

Thank you, everyone. I appreciate your guidance. I understand the difference between impact resistance and abrasion-resistance, which translates to abuse-resistance in the gypsum board world. I have concluded that "extreme-duty," "ultra-high," and "very-high" are just superlatives that are meaningless in the specifications.


Terms like "Commercial grade" and "Heavy-duty" are sometimes valid descriptors when actually defined in a consensus standard. But in the case described, they are not.


A brief plug for joining SCIP: In addition to the camaraderie with fellow professional specification writers, membership includes a subscription to Madcad Codes, which gives you access to a lot of ASTM standards.
Rosa Cheney
Senior Member
Username: rdcaia

Post Number: 16
Registered: 07-2018
Posted on Wednesday, June 24, 2020 - 01:45 pm:   Edit PostDelete PostPrint Post

On a related note, impact-resistant gypsum board requires a thicker metal stud. The product data should have specific info, as does the Gypsum Association.

https://gypsum.org/commercial-applications/impact-resistant-gypsum-panels/
Phil Babinec
Senior Member
Username: pbabinec

Post Number: 31
Registered: 09-2004
Posted on Thursday, June 25, 2020 - 06:05 pm:   Edit PostDelete PostPrint Post

VHI is a marketing term but as mentioned per ASTM C1629 there are classification levels for Impact Resistance.
Comes into play with high rise stair enclosures: (2) layers of Level 2 or 1 layer of Level 3.

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