| Author |
Message |
Jerome J. Lazar, RA, CCS, CSI, SCIP
Senior Member
Username: lazarcitec
Post Number: 704
Registered: 05-2003
| | Posted on Friday, October 23, 2009 - 12:53 pm: |    |
What are the concerns, if any, in applying 5/8-in thk stone wall tile thinset over 1/2-in gypsum board over 20 ga metal stud interior partition, non wet area? Is a backer board always required in this type of application? |
Ronald L. Geren, AIA, CSI, CCS, CCCA, SCIP
Senior Member
Username: specman
Post Number: 808
Registered: 03-2003
| | Posted on Friday, October 23, 2009 - 01:04 pm: | |
Regular gypsum board is permitted as a substrate for tile in non-wet areas.
Ron Geren, AIA, CSI, CCS, CCCA, SCIP
www.specsandcodes.com |
Steven Bruneel, AIA, CSI-CDT, LEED-AP
Senior Member
Username: redseca2
Post Number: 205
Registered: 12-2006
| | Posted on Friday, October 23, 2009 - 02:12 pm: | |
Tile size is a consideration.
Large tiles can "pop" off because gypsum board can bend and deflect but tiles do not. |
Anne Whitacre, FCSI CCS
Senior Member
Username: awhitacre
Post Number: 915
Registered: 07-2002
| | Posted on Saturday, October 24, 2009 - 08:59 pm: | |
the other consideration, again with large tiles, is that they can be heavy enough to pull the paper off the gypsum board, and that sort of messes up the installation. small tiles, no problem. |
John Bunzick, CCS, CCCA, LEED AP
Senior Member
Username: bunzick
Post Number: 1125
Registered: 03-2002
| | Posted on Monday, October 26, 2009 - 12:15 pm: | |
We have just gone through a decision process with this. We limit deflection on partitions with tile to L/360 on 32 mil studs. Deflection between studs could be as high or higher, IMHO, than gypsum board because these products are not necessarily stiffer. I found that manufacturers of both gypsum panels (I spoke to four) and tile setting materials (I spoke to three) were not especially concerned about large format tile on gypsum board. The special tile base products are significantly more expensive installed than gypsum products.
We are planning to use abuse resistant gypsum as a tile base (due to it's higher "soft-body impact resistance" relative to standard gypsum board) in school corridors with 12 by 24 tile, set with medium bed, non-sag, high-bond polymer modified mortar. Toilet rooms (only the wet-wall gets tile) will be mold and moisture resistant board, with a "flash cove" of waterproofing membrane at the base to protect the board from mop water. |
Anne Whitacre, FCSI CCS
Senior Member
Username: awhitacre
Post Number: 917
Registered: 07-2002
| | Posted on Monday, October 26, 2009 - 02:41 pm: | |
however, if the deflection of the tile is tighter than the deflection of the substrate you can still get popoff if the building moves enough. Not exactly this example, but I worked on an installation for an exterior and we specified L/720 for the exterior finished walls (ie, with the glazing in the windows) and the tile was installed before the windows. the tile cracked off the walls because the wind pressure was enough to flex more than the tile flexure. |
ken hercenberg
Senior Member
Username: khercenberg
Post Number: 40
Registered: 12-2006
| | Posted on Tuesday, November 10, 2009 - 10:04 am: | |
I used to be a tile installer; ran 3 crews and saw lots of things that none of the manufacturers address or seem to care about. I agree with Anne that large format tile doesn't belong on paper faced products. I have also found that wet area applications should be limited to cement board regardless of what manufacturers claim. I'm tired of hearing that mold can't grow on glass fibers (ever see moldy insulation?) and using gypsum in wet areas still scares me, including at exterior sheathing applications. That's why I have always required a waterproof coating over gypsum panels and sheathing no matter what. For the tile over abuse-resistant board, especially if any impact conditions are expected, I'd again lean towards the non-paper-faced products. The USG Fiberock line is much heavier than available glass- or paper-faced gypsum panels and seems to provide a better substrate for this kind of application. Just my opinion. |
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