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Richard Skendzel, CCS CSI (Unregistered Guest)
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Posted on Tuesday, April 04, 2006 - 07:02 am:   Edit PostDelete PostPrint Post

Is anyone aware of a glass block product that, used in a wall assembly, can provide a 1 hour rating, per ASTM E119? The rating for Pittsburgh Corning products that I have found only applies to protected openings, and not fire rated walls.
Ralph Liebing, RA, CSI
Senior Member
Username: rliebing

Post Number: 354
Registered: 02-2003
Posted on Tuesday, April 04, 2006 - 10:10 am:   Edit PostDelete PostPrint Post

Try WECK Glass Blocks out of Glashaus, Inc. at www.weck.com
Ronald L. Geren, RA, CSI, CCS, CCCA, MAI
Senior Member
Username: specman

Post Number: 226
Registered: 03-2003
Posted on Tuesday, April 04, 2006 - 12:31 pm:   Edit PostDelete PostPrint Post

To my knowledge, there're no glassblock assemblies that have passed the ASTM E 119 test. I was curious myself, so I checked out WECK via the internet: what I found was another fine example how manufacturers don't provide enough information for the spec writer or architect on their websites.

To begin with, for an assembly to be considered "fire resistive" (such as walls, floors, and roofs), the assembly must pass the endurance and hose stream tests, AND block radiant heat per ASTM E 119.

Opening protectives only need to comply with UL 257 and UL 80 (Section 715.4, 2003 IBC), which does not test for radiant heat.

Most openings, like Richard referred to, are considered "fire protected," so they only meet the UL criteria stated above.

The WECK website states that some of their block is UL rated, but they never list the specific tests. However, each ASTM standard is listed in the References Article by number and title (somewhat); missing in that list is ASTM E 119.

So, we have to "assume" that the product is only "protective" and not "resistive." Even in their page that is titled "Typical Details and Code Limitations" doesn't address the fire rated aspect of some of their products, let alone the fire resistive/protective issue.

They state that their block has 45, 60, and 90 minute ratings. So some designers, not knowing the difference, might use this product in a condition where only an assembly passing the ASTM E 119 will be allowed per the building code.
Wayne Yancey
Senior Member
Username: wyancey

Post Number: 119
Registered: 05-2005
Posted on Tuesday, April 04, 2006 - 04:08 pm:   Edit PostDelete PostPrint Post


Great summary. Clear and concise.


Brett M. Wilbur CSI, CDT, AIA
Senior Member
Username: brett

Post Number: 111
Registered: 12-2004
Posted on Tuesday, April 04, 2006 - 04:35 pm:   Edit PostDelete PostPrint Post


in Pittsburg Corning’s catalog, they have a technical paper, No. TD-260 "Glass Block Fire Rating Facts", dated July 26, 2002. It states:

"All Underwriters (UL) fire-rated glass block on the market are tested in accordance with UL 9 (Fire Test of Window Assemblies) for a 45-minute or longer period. All national model building codes recognize this test. The UL window assembly tests performed on glass block do not qualify glass block products for use as wall assemblies. Presently, no glass block are qualified as fire-rated wall assemblies because none can pass the UL wall assembly test.”

The “UL wall assembly test” is the ASTM E 119, as Mr. Geren states above. Basically, E 119 measures heat transmission, temperatures on the unexposed side, and passage of smoke or production of gases hot enough to ignite combustibles. All of which are not required for the window assembly test, ASTM E163 (UL 9). The wall assembly must also pass the hose stream test. No openings may develop that allow water to pass through during the hose stream test. E 163 allows up to 30 percent openings in panel.

The technical paper goes on the state:

“In spite of the fact that 45-, 60-, and 90-minute fire-rated glass block exist, architects, designers or building owners could be mislead into believing that these glass block would be acceptable for fire-rated wall assembly installation. In reality, these test results carry no implications as to qualification of these products for use as a fire-rated wall assembly.”

Anyway, it goes on to describe specific test procedures and findings. I can email you a PDF of the technical paper if you like, email me at wilbur@pbkarchitects.com.
Posted on Tuesday, April 04, 2006 - 04:38 pm:   Edit PostDelete PostPrint Post

So...it sounds like you can use glass block in rated a wall, as long as it is 25% or less of the wall's area, just like normal glazed openings.
Ronald L. Geren, RA, CSI, CCS, CCCA, MAI
Senior Member
Username: specman

Post Number: 227
Registered: 03-2003
Posted on Tuesday, April 04, 2006 - 04:58 pm:   Edit PostDelete PostPrint Post

Anon: Yes.

Just to clarify further, if the opening can operate (i.e. slide, hinge, etc.) it will never be accepted where openings are prohibited, whether or not it can pass ASTM E 119. The fact that it can be opened (and potentially left open) negates the fire-resistive properties.
Posted on Tuesday, April 04, 2006 - 05:02 pm:   Edit PostDelete PostPrint Post

right! That's what fire shutters are for :-)

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