STUCCO CONTROL JOINTS ON SOLID SURFACES

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Author Message Jerome J. Lazar, RA, CCS, CSI, SCIP Senior Member Username: lazarcitec Post Number: 1025 Registered: 05-2003 Posted on Wednesday, January 08, 2014 - 11:34 am:    ASTM C926 REFERS TO CONTROL JOINTS OVER LATH INSTALLATION, FOR SOLID SURFACES ASTM C1063 IS REFERENCED, ARE THERE ANY OTHER WRITTEN REQUIREMENTS FOR CONTROL JOINTS OVER SOLID SURFACES IN REGARDS TO THE APPLICATION OF STUCCO, I CAN FIND NONE. ken hercenberg Senior Member Username: khercenberg Post Number: 674 Registered: 12-2006 Posted on Wednesday, January 08, 2014 - 12:59 pm:    Always found these folks to be handy http://www.tlpca.org/technical_resources0.aspx Usually find that no matter how many you put in, you need more. Liz O'Sullivan Senior Member Username: liz_osullivan Post Number: 120 Registered: 10-2011 Posted on Wednesday, January 08, 2014 - 01:02 pm:    And architects LOVE them, Ken. ; ) Bryan Stanley (Unregistered Guest) Unregistered guest Posted on Wednesday, January 08, 2014 - 01:41 pm:    Ken, you may find Technical Bulletins 60.155,60.160 and 60.210 Helpful. Below is the link to our Website.http://www.tsib.org/technical.shtml# You can also find our "online plaster manual" on our site. A third source is at http://www.naamm.org/emla/emla_technical_literature.aspx Bryan Stanley Technical Advisor Technical Services Information Bureau Nina Giglio Senior Member Username: ngiglio Post Number: 9 Registered: 01-2006 Posted on Wednesday, January 08, 2014 - 02:01 pm:    Jerome, ASTM C926 in A2.3.1 indicates that stucco over solid plaster bases are exempt from the control joint criteria indicated in C1063 - which includes expansion joints in the base and or where dissimilar materials occur ken hercenberg Senior Member Username: khercenberg Post Number: 677 Registered: 12-2006 Posted on Wednesday, January 08, 2014 - 02:08 pm:    Nina, that's true, but I've found that stucco often needs more control joints than those found in solid backing materials, especially in the case of substrates such as concrete and engineered/reinforced CMU. Unfortunately, ASTM doesn't address that reality. Bryan, thanks for those resources. I look forward to having time to review them and hope to add them to the arsenal. Nina Giglio Senior Member Username: ngiglio Post Number: 10 Registered: 01-2006 Posted on Wednesday, January 08, 2014 - 03:18 pm:    Best practices vs "requirements" . While I agree that it is better practice to include control joints, Jerome's question indicated "requirements" which many times are different. ken hercenberg Senior Member Username: khercenberg Post Number: 678 Registered: 12-2006 Posted on Wednesday, January 08, 2014 - 03:22 pm:    Sad but true. What's a Specifier to do (other than post questions here)? Jerome J. Lazar, RA, CCS, CSI, SCIP Senior Member Username: lazarcitec Post Number: 1026 Registered: 05-2003 Posted on Wednesday, January 08, 2014 - 04:00 pm:    The question came up on a CBS construction 3-4 story apartment project currently under construction where the architect does not call for control joints and the GC wants to install them. The Architect has had a history of stucco accessory failures and has recently requested we no longer specify stucco accessories. On this particular building there are no long expanses of walls, the exterior wall goes in and out along the façade. The GC has argued that installing control joints is an Industry Standard and a Requirement of the ASTM Standards typically addressed for this work. Being that this is a long time client with repeat work each year for the past 12, I find the need to prepare a modified stucco spec section void of accessories, to suit their needs for all their upcoming work. Perhaps I should talk to a much older specwriter with experience writing specs before accessories became so prevalent as I am uncertain of how to prepare this spec without preparing DIY text. ken hercenberg Senior Member Username: khercenberg Post Number: 679 Registered: 12-2006 Posted on Wednesday, January 08, 2014 - 04:07 pm:    Just curious as to types of accessories the architect has had issues with (zinc, plastic, other), including which configurations (one-piece vee, two piece, etc) and how they were implemented in relationship to the backup. Lots of good reasons why accessories fail. One thing I'm not sure about is if placement of accessories in stucco are similar to other types of masonry products in terms of corners and changes in plane. In most forms of masonry that I'm aware of, you still need to maintain your control joint spacing. The other concern occurs where you have 'natural' breaks such as openings in your wall. Just because you don't put in a control joint accessory doesn't mean that nature won't put in a control joint for you later. Dave Metzger Senior Member Username: davemetzger Post Number: 487 Registered: 07-2001 Posted on Wednesday, January 08, 2014 - 04:09 pm:    Who's going to admit to being "a much older specwriter"? Without including myself in that group, I'd hazard a guess that pre-accessories stucco had a higher lime and lower cement content than is used today. What was the root cause of the stucco accessory failures your client has experienced? Were the accessories galvanized? PVC? Both of which I could see issues with in south Florida. Frankly Jerome, I agree with the contractor in this case. I'd recommend zinc control joints. But then I'm not a much older spec writer. Jerome J. Lazar, RA, CCS, CSI, SCIP Senior Member Username: lazarcitec Post Number: 1027 Registered: 05-2003 Posted on Wednesday, January 08, 2014 - 04:46 pm:    perhaps the use of the term older was inappropriate, hell I just hit 60 and I feel like an old F___t...still writing specs probably until the day I die...pathetic I know. Dave at least you are retired to some extent, enjoying your senior years...so perhaps I should changed the word "older" to 'super-senior" Lynn Javoroski FCSI CCS LEED® AP SCIP Affiliate Senior Member Username: lynn_javoroski Post Number: 1739 Registered: 07-2002 Posted on Wednesday, January 08, 2014 - 04:59 pm:    "more experienced" "elder" "venerable" "revered" "supreme" "distinguished" "more advanced" "more skillful" "senior" "more expert" just to choose a few other words we could use... John Hunter Senior Member Username: johnhunter Post Number: 111 Registered: 12-2005 Posted on Wednesday, January 08, 2014 - 05:18 pm:    It would be interesting to know the architect's definition of "failures." Mark Gilligan SE, Senior Member Username: mark_gilligan Post Number: 629 Registered: 10-2007 Posted on Wednesday, January 08, 2014 - 06:16 pm:    If the stucco is directly adhered to concrete it is not clear how the strain can be accumulated at the joints. If you are worried about cracks in the concrete then you need to not adhere the stucco directly to the concrete. ken hercenberg Senior Member Username: khercenberg Post Number: 680 Registered: 12-2006 Posted on Wednesday, January 08, 2014 - 06:39 pm:    That's part of my point Mark. Stucco has its own properties. It's a thin film of mortar-like material applied to the substrate and will tend to crack no matter how high the quality and the amount of tensile-adding-reinforcement (even horse hair) or modifiers like so-called one-coat systems. Even in regions where workers understand the product like Florida and Texas, there seem to be designers who don't understand the need to design stucco in square-shaped panels typically not exceeding about 20 feet in both directions, and that's presuming that you've designed the entire system properly. From what I've seen, mirroring the joints in the substrate has been a serious cause for failure. It's just asking too much of a material that's not designed for that use. Mark Gilligan SE, Senior Member Username: mark_gilligan Post Number: 630 Registered: 10-2007 Posted on Wednesday, January 08, 2014 - 11:49 pm:    Cracks in stucco applied directly to concrete will not be prevented by installing joints every 8 feet.