Is Type X Gypsum Board better than Re...

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Author Message Jerome J. Lazar, RA, CCS, CSI, NCARB Senior Member Username: lazarcitec Post Number: 1714 Registered: 05-2003 Posted on Wednesday, October 05, 2016 - 02:35 pm:    The Architect drawings call for Type X Gyp Board in partitions that are not required to be fire rated, the GC wants to substitute with standard Gyp Board of same thickness. Is this acceptable? Is Type X stronger? Dewayne Dean Senior Member Username: ddean Post Number: 94 Registered: 02-2016 Posted on Wednesday, October 05, 2016 - 02:40 pm:    This might be more info than you want, but here it is Regular gypsum board, after water is driven off by heat from a fire, reduces in volume, develops large cracks in the board, and eventually fails. A 5/8 inch regular gypsum wallboard panel exposed to 1850°F., will fail in 10 to 15 minutes. By extrapolation, a 1/2-inch board would probably fail in 10 to 12 minutes. Type X has a glass fiber reinforced gypsum core. The fibers reduce the extent and severity of cracks in the board when exposed to flame and heat, thus increasing the time it performs without failure. Tests show that Type X board, exposed to the same 1850° heat will remain effectively in place for 45 minutes. It, too, ultimately fails Jerome J. Lazar, RA, CCS, CSI, NCARB Senior Member Username: lazarcitec Post Number: 1715 Registered: 05-2003 Posted on Wednesday, October 05, 2016 - 02:43 pm:    Dewayne, appreciate the quick response, but my client does not need fire resistance, the question is other than fire resistance is Type X better than Standard? Dewayne Dean Senior Member Username: ddean Post Number: 95 Registered: 02-2016 Posted on Wednesday, October 05, 2016 - 02:49 pm:    Jerome, "Type X has a glass fiber reinforced gypsum core." This should make it stronger. George A. Everding, FCSI, CCS, CCCA, AIA Senior Member Username: geverding Post Number: 831 Registered: 11-2004 Posted on Wednesday, October 05, 2016 - 02:58 pm:    My understanding is that regular gypsum board is 1/2" and Type X is 5/8". This has to do with efficiencies in manufacturing. At one time, you could get either in either thickness, but several years ago the manufacturers decided to standardize. 5/8" regular would therefore now be a special order, and probably end up costing more than 5/8" type x. It's been several years since I have been involved in writing Division 09 specs, so you should verify this information from one of the major gypsum companies, National or USG. Let me know what you find out, if this is still the case. Michael Chusid, RA FCSI CCS Senior Member Username: michael_chusid Post Number: 221 Registered: 10-2003 Posted on Wednesday, October 05, 2016 - 02:58 pm:    "should make it stronger" is a reasonable assumption, but performance also depends on the gypsum board, gypsum to fiber bond, paper faces, etc. Test data would be a more useful. I am sure the major gyp board companies can answer. But first, what type of strength is customer looking for? - Flexural - Fastener head pull-over. - Shear - Wet strength - Impact - Crushing Did architect have a bad experience that he/she is trying to avoid? Let us know what you find out as I am interested. Michael Chusid, RA FCSI CCS www.chusid.com www.buildingproduct.guru 818-219-4937 Dave Metzger Senior Member Username: davemetzger Post Number: 660 Registered: 07-2001 Posted on Wednesday, October 05, 2016 - 03:12 pm:    It's easy to overthink this. On several of our projects, the architect wanted to use Type X for all partitions because there was less field management and inspection required to make sure that the correct type gypsum board was installed in each partition. Having just one type of board solved this problem by avoiding it. The cost savings in the GC's field management outweighed any additional material and labor costs involved with using Type X board everywhere--though this may vary in different locations. Another consideration is that 5/8" board provides higher STC ratings--is that an issue for the architect? Sheldon Wolfe Senior Member Username: sheldon_wolfe Post Number: 929 Registered: 01-2003 Posted on Wednesday, October 05, 2016 - 03:15 pm:    My thoughts, too, Dave. George, 1/2 inch Type X is available. I recall the rumor, several years ago, that non-rated 5/8 inch board was going to be discontinued. Apparently, the economics don't justify doing so. Jerome J. Lazar, RA, CCS, CSI, NCARB Senior Member Username: lazarcitec Post Number: 1716 Registered: 05-2003 Posted on Wednesday, October 05, 2016 - 03:36 pm:    In So Florida its always about $$$, Architect called for Type X everywhere because it is a condo and more sound control is always better, the UL Assembly calls for 5/8 in. not 1/2 in. The Developer wants to reduce cost anyway he can, so he has asked the GC to cut corners and reduce cost. The bigger problem is going to be if all these changes are going to be documented in a record set, Florida Statutes require that the Developer turn over to the Condo Association a set of documents that depict the actual construction, however this is barely ever done. When problems start developing with construction defects questions will be asked as to why construction in place does not match the drawings. Condo home owners do not care about the Developer wanting to save $$$, they want to know if they have been short changed. These days sound control litigation is more likely than mold and mildew. The difference in gyp board thickness could certainly backfire on the Developer and the Architect. Jerome J. Lazar, RA, CCS, CSI, NCARB Senior Member Username: lazarcitec Post Number: 1717 Registered: 05-2003 Posted on Wednesday, October 05, 2016 - 03:42 pm:    Keep on responding, I have to leave the computer and put my shutters in place before the rain starts...yes I am in Broward County and we are going to have a visit from a storm called Matthew in 24 hours, so much fun I can not tell you. Gas stations starting running out of gas last night. Don Harris CSI, CCS, CCCA, AIA Senior Member Username: don_harris Post Number: 292 Registered: 03-2003 Posted on Wednesday, October 05, 2016 - 04:00 pm:    Like Dave above, we use Type X for everything that doesn't require Type C. I was told by a contractor years ago that the cost difference between 1/2 and 5/8 X is nothing compared to the redo if some idiot puts 1/2 where the 5/8 belongs. 5/8 definitely gives better STC than 1/2. University clients of ours require 5/8 everywhere. Guest (Unregistered Guest) Unregistered guest Posted on Wednesday, October 05, 2016 - 08:01 pm:    Have the GC tell developer to hire 3rd party inspector to continuously monitor installation so 1/2-inch isn't installed on rated partitions? Or better yet, GC's change order proposal should include such inspection...that should more than offset cost savings (if any) for using 1/2-inch board? anon (Unregistered Guest) Unregistered guest Posted on Wednesday, October 05, 2016 - 03:31 pm:    Sheldon, it's still available: https://www.usg.com/content/usgcom/en/products-solutions/products/wallboard/lightweight-panels/usg-sheetrock-ultralight-panels-firecode-30.html Brian Payne, AIA Senior Member Username: brian_payne Post Number: 64 Registered: 01-2014 Posted on Tuesday, October 25, 2016 - 02:49 pm:    Don't be confused between Regular 5/8" and the newer Ultralight 5/8". The Ultralight is 30% lighter which is great on installers, but that 30% in weight will have a negative effect on acoustical STC. (Which as far as I know has yet to be substantiated.) Be careful that the contractor is not using ultralight for non-rated walls. We are doing an office remodel right now, and the contractor is using 1/2" ultralight for the sound/dust partition. Not good.