| Author |
Message |
Robin E. Snyder
Senior Member
Username: robin
Post Number: 365
Registered: 08-2004
| | Posted on Wednesday, August 03, 2011 - 05:49 pm: |    |
My client is installing granite tiles (24 x 24 x 1/2 inch) on an exterior facade, up to a height of 50+ feet. The original tile fell off, and we believe it was due to lack of sufficient coverage of the mortar. Structural engineer says the building will not support the weigh of lath/scratch/brown coat installation. Architect submitted the following to the building department: Studs, Tyvek, Cement Board, fluid waterproofing, medium bed, tile. Build Dept rejected and insists on mechanically fastening the tile. Any suggestions on the best way to do this when the tile is only 1/2 inch thick (1/8 inch grout joints). |
Phil Kabza
Senior Member
Username: phil_kabza
Post Number: 481
Registered: 12-2002
| | Posted on Wednesday, August 03, 2011 - 05:57 pm: | |
How about those big exposed bolt heads that were the design architect rage d'jour a few years ago? Otherwise, Dryvit. Gluing this stuff on a stud-framed wall is not going to end well. |
Mark Gilligan SE,
Senior Member
Username: mark_gilligan
Post Number: 408
Registered: 10-2007
| | Posted on Wednesday, August 03, 2011 - 11:35 pm: | |
Since you have already had a failure one time I would recommend that they retain a consultant to find the cause.
Problems could have been caused by too flexible of a backing wall, creep in wood or concrete construction, inability to accommodate variations in thermal expansion and contraction. I believe that thinner granite units are more subject to warping.
You may want to contact Masonry Institute of America for information and possible referrals to experts. They have a useful book titled “marble and Stone Slab Veneer”
I tend to believe that mechanical anchoring is the way to go but it is not clear what code provision the building department referenced when rejecting the submission.. |
Justatim
Senior Member
Username: justatim
Post Number: 18
Registered: 04-2010
| | Posted on Thursday, August 04, 2011 - 07:41 am: | |
I'd investigate 1) the bond between the fluid waterproofing and mortar bed (was separation here or between the tile and mortar bed?), and 2) perhaps using soft, sealant joints to accommodate and distribute any flexural or expansive movements. You didn't say your climate, but you might investigate how Mexicans and South Americans do their very high tile walls. |
Robin E. Snyder
Senior Member
Username: robin
Post Number: 366
Registered: 08-2004
| | Posted on Thursday, August 04, 2011 - 10:11 am: | |
Maybe I should clarify my question...
1) consultant did find the cause - poor coverage of the mortar on the back of tiles and insufficient expansion joints. We have remedied the lack of expansion joints on the new design and plan to have someone oversee installation to ensure the tile is installed properly.
2) The weight of the structure will not accomodate lath/scratch/brown coat.
3) The submitted assembly is a TCNA and MIA accepted assembly (high strength mortar over fluid applied membrane over cement board over tyvek) but the building dept rejected it, even though the size of the tile falls within the accepted limits of adhered veneer. They want the tile mechanically fastened.
4) QUESTION - does anyone know of a way to mechanically fasten 24 x 24 x 1/2 inch tile (besides lath)? The only veneer ties I am familiar with are for thicker panels. |
Gerard Sanchis
Senior Member
Username: gerard_sanchis
Post Number: 37
Registered: 10-2009
| | Posted on Thursday, August 04, 2011 - 12:08 pm: | |
Robin,
I have seen 2 types of mechanical anchors used in Europe for thin tiles. Both remain exposed. The first engages 4 corners of adjacent tiles; the second consists of L-shaped clips with a return leg engaging the tile. Both were stainless steel. The corner piece was approximately 3 inches in diameter with an exposed fastener in the center, and the clip was approximately one inch wide with concealed fasteners.
Given the fact that the building department will not accept what is by code an acceptable method of installing thin stone veneer, I don’t know of any other fastening method that could be used in your case, but my knowledge is limited and there may be a system that I’m not aware of.
Hope this helps. |
J. Peter Jordan (Unregistered Guest)
Unregistered guest
| | Posted on Thursday, August 04, 2011 - 12:12 pm: | |
I am tempted to start a rant about AHJ creating new provisions in the code without going through the proper channels (have several instances of that here in Houston). If you could ask them to cite the section where this method of installation is required...maybe?
I suspect the drawings submitted indicated stone, and the plan reviewer simply can't get past the "stone" to see the "tile."
In the absence of being willing to buck the system a bit, I believe an exposed fastener system will be required like Mark indicates. In order to use the more traditional system, you may have to increase the thickness of the stone veneer to the point where it would weigh as much if not more than a tile with a mud bed.
The location of the backup framing is critical to having an exposed faster system work unless you are willing to strip the wall with supplementary framing, but you could wind up with "buttons" (stainless steel or bronze) about 2 to 3 inches in from each corner. |
Julie Cox Root, AIA
Senior Member
Username: julie_root
Post Number: 95
Registered: 02-2004
| | Posted on Thursday, August 04, 2011 - 12:31 pm: | |
We have done adheared assemblies successfully, but have stayed with smaller sizes because I am in CA in an earthquake zone which has influenced our assembly in other parts of the country.
The toughest investigation we have had on the subject is the mix of the mortar causing the mix to dry out too soon despite the contractor's best attempts to keep it wet. I cannot remember the exact mineral that was causing the trouble in the mix, but besides the issue with poor coverage on the mortar, there was also the element in the mix. Again we do not do anything over 12 x 12 tile and often smaller because we like to use stone that also has more thickness in a 'faux dry' stack kind of method.
I highly recommend Morrison Hershfied, specifically Stephan Hoffman either in in their SF or WA office.
http://www.morrisonhershfield.com/Pages/default.aspx
We also tested expoxy systems with a present contractor in order to head off some conditions we have encoutered. Stephan has a really strong background in facade conditions and while they do the whole structural system we have used him for just the facade attachements. |
Wayne Yancey
Senior Member
Username: wayne_yancey
Post Number: 481
Registered: 01-2008
| | Posted on Thursday, August 04, 2011 - 01:18 pm: | |
Robin,
You may want to consider Knight Wall Systems out of Spokane WA. We used their thin brick system for a medical office building in Ballard, WA.
http://www.knightwallsystems.com/ |
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