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.
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?
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
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.