Where are the expansion joints?

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Author Message Jerome J. Lazar, RA, CCS, CSI, NCARB Senior Member Username: lazarcitec Post Number: 1844 Registered: 05-2003 Posted on Monday, December 11, 2017 - 06:25 pm:    A client (the Architect) asked me (the specifier) where he should place expansion joints? My answer was simple, how should I know, you are the Architect? He clarified and asked where are expansion joints usually placed? Well I used to know some rules of thumb as to where expansion joints should go, do any of my colleagues have a link to a web page that my client can check out or can someone share that knowledge that I seem to have forgotten. He thought ASTM would have a standard for this? Or the Florida Building Code? Michael Chusid, RA FCSI CCS Senior Member Username: michael_chusid Post Number: 349 Registered: 10-2003 Posted on Monday, December 11, 2017 - 06:29 pm:    Please clarify if you are asking about masonry expansion joints (for use with clay masonry) or building expansion joints? Michael Chusid, RA FCSI CCS 1-818-219-4937 www.chusid.com www.buildingproduct.guru Jerome J. Lazar, RA, CCS, CSI, NCARB Senior Member Username: lazarcitec Post Number: 1845 Registered: 05-2003 Posted on Monday, December 11, 2017 - 06:41 pm:    Building Expansion Joints. Jerome J. Lazar, RA, CCS, CSI, NCARB Senior Member Username: lazarcitec Post Number: 1846 Registered: 05-2003 Posted on Monday, December 11, 2017 - 06:42 pm:    Building Expansion Joints Liz O'Sullivan Senior Member Username: liz_osullivan Post Number: 238 Registered: 10-2011 Posted on Monday, December 11, 2017 - 06:48 pm:    Sounds like a job for the Structural Engineer. Not all buildings need expansion joints, though. Brian Payne, AIA Senior Member Username: brian_payne Post Number: 121 Registered: 01-2014 Posted on Monday, December 11, 2017 - 06:51 pm:    https://www.aisc.org/globalassets/modern-steel/steelwise/052011_may11_steelwise_web.pdf Guest (Unregistered Guest) Unregistered guest Posted on Monday, December 11, 2017 - 08:24 pm:    I think "expansion" is a misnomer, as, in Calif., it's often referred to as seismic joints. But whatever the cause of displaced movement, I've always preferred "separation" joints, which in turn permit independent movements of each portion, regardless of the cause (wind, thermal, seismic, blast). Most all my encounters, the structural engineer dictates where and how (extent and direction) these "joints" need to move. Nathan Woods, CSI, CCCA, LEED AP Senior Member Username: nwoods Post Number: 728 Registered: 08-2005 Posted on Monday, December 11, 2017 - 11:53 pm:    For fun, ask your architect/client what the calculated inelastic drift will be at the highest point of the building.... J. Peter Jordan Senior Member Username: jpjordan Post Number: 1008 Registered: 05-2004 Posted on Tuesday, December 12, 2017 - 07:26 am:    I always defer to the structural engineer, and I am frequently surprised by the response. Some buildings that I would feel sure need them don't and vice versa. In addition to the causes listed by "guest" above, you can add differential settlement as well as isolation due to fire-resistance construction. What I find is that most of my clients (architects) put off selecting products and detailing until the end of the CD phase. It is usually more detailed and complex than they believe it will be, and I usually have to generate a very broad section to cover them. J. Peter Jordan, FCSI, AIA, CCS, LEED AP, SCIP Brian E. Trimble, CDT Senior Member Username: brian_e_trimble_cdt Post Number: 98 Registered: 08-2005 Posted on Tuesday, December 12, 2017 - 10:17 am:    And if you don't put in building expansion joints, I can show you a building in Central PA that was 700' long that didn't have any and the resulting cracks. But as many have said, its the designer's (A or E) job to "design" these joints. While there may be some rules of thumb, this is a pretty critical detail that should have analysis behind it, not guessing. This leads me to another question about "unintended" delegated design. We have some architects and/or specifiers who write into their specs for the mason contractor to place "expansion and control joints in the building according to BIA and NCMA literature". But this is a design decision not a installers concern. The mason should only place them where the plans show them and not be doing that on their own. Same thing goes with wall ties that exceed the 4 1/2" cavity. Its not the masons job to engineer these wall ties, but the architect's or engineer's role. Is all of this the result of decreased design time and lower fees, or maybe the shifting of liability? ken hercenberg Senior Member Username: khercenberg Post Number: 1140 Registered: 12-2006 Posted on Tuesday, December 12, 2017 - 01:03 pm:    Brian, thanks for pointing these items out. I think a lot of designers don't have this on their radar. When it comes to masonry, our engineers have little involvement regarding joint design or spacing. Even more so, with the increase in insulation depth, I know few Architects who understand that 4-1/2 inches is about the max that conventional ties are engineered for. Greta Eckhardt Senior Member Username: gretaeckhardt Post Number: 71 Registered: 08-2013 Posted on Tuesday, December 12, 2017 - 01:28 pm:    I agree with "Guest" in thinking the phrase expansion joint is a misnomer. A joint between portions of the building that allows for differential movement due to seismic forces or settlement of the building not only needs to be located by the structural engineer, it needs to be an integral feature of the structural design. The Structural Engineer must also determine its width and the anticipated movement across that joint. I would prefer to call it STRUCTURAL MOVEMENT JOINT or something like that but Masterspec and the rest of the industry continues to call it an expansion joint so I don't fight it (for now). It is a joint that extends from exterior to interior construction. Therefore, once the Architect knows where and what it is, they are responsible for designing a cover and fill that will maintain continuity of the thermal/water/air or fire control layer across it, and the Architect must show these things on their drawings. As I think we all know, various materials in the construction of a building also need joints because they expand or shrink for various reasons and we would like to control where that movement occurs. In an ideal world, we would call these CONTROL JOINTS. Specifications can refer to standards for the maximum distance between such joints. However, any Architect who does not locate them on the drawings is going to see some ugly lines or cracks just where they don't want them on masonry facades, tile floors, gypsum board walls and other construction. As specifiers, the best thing we can do is act as a nudge or nag, letting the Architect know that they need to consider both these types of joints a a part of design that must be located and detailed on the drawings - just naming products and including references to standards in specifications is not going to result in a successful design. Dave Metzger Senior Member Username: davemetzger Post Number: 712 Registered: 07-2001 Posted on Tuesday, December 12, 2017 - 02:17 pm:    Actually, there is a difference between “control joints” and “expansion joints” in masonry. The following is excerpted from an article in The World of Masonry Construction. CMU shrinks as it loses moisture, so control joints are typically used in CMU to reduce the occurrence of shrinkage-related cracking. Although CMU masonry expands during warm weather, it generally expands less than it shrinks. Expansion joints are typically used to accommodate thermal and moisture expansion in clay brick masonry, because clay brick masonry expands over time. So these joints in CMU are properly called "control joints" and in clay brick masonry are called "expansion joints". Greta Eckhardt Senior Member Username: gretaeckhardt Post Number: 72 Registered: 08-2013 Posted on Tuesday, December 12, 2017 - 02:50 pm:    Thanks for the correction, Dave! Then ideally we would identify and label 3 types of joints: structural movement joints, expansion joints and control joints. Mark Gilligan SE, Senior Member Username: mark_gilligan Post Number: 835 Registered: 10-2007 Posted on Tuesday, December 12, 2017 - 04:36 pm:    There are several possible reasons for jointing a building. These include seismic or wind movement, differential temperature change during the life of the building, and shrinkage of concrete or masonry. This is not a decision that can be made without the structural engineer's involvement. Location of the joints will have major impact on the lateral system. Some of the recommendations on masonry control joints were developed in the context of little to no reinforcement in the masonry. With sufficient reinforcement shrinkage crack sizes can be controlled so you do not need as many joints. Brett Scarfino (Unregistered Guest) Unregistered guest Posted on Thursday, December 14, 2017 - 11:58 am:    I'm not sure that all joints fit nicely into simplified categories. I like the idea of thinking about them all as "joints". On a fundamental level, the joint is there to absorb movements and tolerance(s). Movements might come from skeletal deflections and long term movements (as Mark noted, S.E./Arch. coordination), from the skin components themselves (thermal/moisture induced movements, deflections under load...), or a combination of both; through-wall or just in a few wall components. Mark Gilligan SE, Senior Member Username: mark_gilligan Post Number: 836 Registered: 10-2007 Posted on Thursday, December 14, 2017 - 01:37 pm:    My sense is that with respect to the skin much of the movement is accommodated locally but on long buildings long term concrete shrinkage or significant temperature changes can result in some columns leaning or high unanticipated forces. These are issues that the structural engineer is in a better position to consider than the architect. Also if the architect were to make a decision to joint the building without discussion with the structural engineer this could cause major problems for the lateral system. To be blunt an architect should not make decisions regarding jointing of the building without consulting with the structural engineer. An architect who does not understand the need for this should probably have his license revoked. Dave Metzger Senior Member Username: davemetzger Post Number: 713 Registered: 07-2001 Posted on Thursday, December 14, 2017 - 01:47 pm:    Yes, it's important that the architect and structural engineer arrive at a joint decision. Michael Heinsdorf, P.E. Senior Member Username: michael_heinsdorf_pe Post Number: 31 Registered: 01-2014 Posted on Thursday, December 14, 2017 - 02:20 pm:    Nice one, Dave. Also keep in mind that expansion joints need to be coordinated with other disciplines and may require additional design work. Electrical conduit may require relief, HVAC equipment locations should be checked, etc. Dewayne Dean Senior Member Username: ddean Post Number: 147 Registered: 02-2016 Posted on Thursday, December 14, 2017 - 03:27 pm:    you guys crack me up Ronald L. Geren, FCSI, AIA, CCS, CCCA, SCIP Senior Member Username: specman Post Number: 1486 Registered: 03-2003 Posted on Thursday, December 14, 2017 - 03:58 pm:    To expand on the subject, maybe referring to them as "Movement Joints" is more to the point and covers all aspects of building movement: shrinkage, wind, seismic, settlement, thermal expansion/contraction, etc. Ron Geren, FCSI, AIA, CCS, CCCA, SCIP www.specsandcodes.com Jeffrey Wilson CSI CCS SCIP Senior Member Username: wilsonconsulting Post Number: 245 Registered: 03-2006 Posted on Thursday, December 14, 2017 - 04:35 pm:    That's a great idea, Ron. So if participants on this forum wanted to start a movement (the "Movement Joint Movement"!) who would we have to convince to get a general consensus for this term? Jeffrey Wilson CCS CSI SCIP Wilson Consulting Inc Ardmore PA Ronald L. Geren, FCSI, AIA, CCS, CCCA, SCIP Senior Member Username: specman Post Number: 1487 Registered: 03-2003 Posted on Thursday, December 14, 2017 - 04:59 pm:    If someone is willing, they can put a request into MasterFormat.com to change the section titles from "Expansion" to "Movement." Thus: 07 71 29 - Manufactured Roof Movement Joints 07 95 00 - Movement Control 07 95 13 - Movement Joint Cover Assemblies 07 95 63 - Bridge Movement Joint Cover Assemblies Ron Geren, FCSI, AIA, CCS, CCCA, SCIP www.specsandcodes.com Greta Eckhardt Senior Member Username: gretaeckhardt Post Number: 73 Registered: 08-2013 Posted on Thursday, December 14, 2017 - 05:04 pm:    While I think "movement joint" is a fine generic term for all the joints we have been discussing, I also think it is important to distinguish between the 3 types. Here is the nomenclature I would propose. CONTROL JOINTS involve a single material that can crack due to the fact that it shrinks over time, so we want to control where the crack occurs, usually with guidelines from an ASTM standard. Sometimes these joints need to be coordinated with joints in overlying materials, such as tile over concrete, but the standard is based on a single material. Control joints are usually gaps spanned by a flexible trim or saw-cut joints that are filled with sealant. Architects need to locate these on their drawings. EXPANSION JOINTS are needed to accommodate the expansion of a material such as brick or metal. Again this is a joint governed by the properties of a single material, and they comprise a gap filled with a compressible filler. Architects need to locate these in their drawings, . STRUCTURAL MOVEMENT JOINTS are much more complex because they often allow for multiple types of movement of the building structure as a whole due to seismic, wind, thermal and settlement forces. They involve many materials as they extend from interior to exterior surfaces, and they must be continuous from roof to wall to foundation. Providing a cover/fill involves maintaining continuity across the joint for thermal, water and air barriers. These joints must be located by the structural engineer as a feature of their structural design, but they need also to be located and detailed by the Architect on their drawings.