Mechanical expansion joint covers are designed to accommodate structural movement in a building due to thermal shrinkage and expansion of a building’s structure, or the impact of environmental factors like seismic activity. However, because expansion joints are manufactured differently according to their intended application, it’s integral to choose the correct type.
As an engineer or architect, it’s up to you to properly specify the right expansion joints for each building. Here’s a simple guide.
Expansion joint selection criteria
To properly specify expansion joints, you’ll need to take into account the following aspects of your construction application. You can also try using our free Product Selection Assistant.
Application
Assess where expansion joint covers will be required. For instance, will they be used between floor to floor, floor to wall, wall to ceiling, or wall to wall? This will make a difference to how you can specify expansion joint covers correctly to fit the structure.
Joint width at installation
Measure the joint width in the structural slab to ensure you are specifying the correct expansion joint covers.
Range of movement
Consider both the + (positive) and - (negative) range of movement. The positive will include the effective amount the joint cover needs to extend in width and the negative will include the effective amount the joint cover must contract in width. This will need to be established by the structural engineer.
Also note that expansion joint covers are specified according to their standard installation configuration. If being installed in an alternative position, bear in mind that this will change the available ± movement, but will not alter the total range of movement available.
Location
You'll need different expansion joints depending on whether their application will be indoors or outdoors.
Set down depth
If the floor expansion joint is being installed with a set down for the floor finish, it is important to know the depth of this and the thickness of the flooring finish whether it is stone, carpet, timber or any other floor covering, be prepared with all measurements (in millimetres) before exploring which product is most appropriate.
Floor finish
Expansion joint covers are manufactured in a range of depths to accommodate different flooring surfaces; including stone, tiles, carpet, vinyl, timber and concrete. Alternatively, if you require a joint cover for an application where two floor surfaces meet, a composite joint system can be created.
Speak to a Latham representative here about creating custom expansion joint solutions.
Cover plate material
Choosing the right expansion joint depends on the cover plate material - from aluminium to stainless steel, brass and other materials. Our expansion joints are designed not only to meet the structural requirements of the building but also to be aesthetically pleasing while architecturally enhancing the structure
Traffic usage
Your choice of expansion joint covers for flooring will also depend on the level of the pedestrian or vehicular traffic it will be exposed to.
Fire rating required
If a fire rating is needed, assess whether a 2 hour or 4 hour rating will be necessary to ensure the expansion joint covers maintain optimal performance in the case of fire. According to Australian standards, Fire Rated Expansion Joint Covers must be tested in accordance with the standard time temperature curve, which subjects all structural components of the product to conditions replicating a fire in a true field installation.
To make the expansion joint specification process simpler we've created a reference system which our expansion joint covers are labelled with.
This enables you to quickly recognise the features available in each product and assess its suitability for your application; including directional movement (which varies from 2, 4 or 6-way continuous multi-directional movement), location of use, fire rating, water gutter use and suitability for seismic and vehicular activity.
To find out more about Latham products, please visit www.latham-australia.com. To talk to a Latham product expert, call 1300 LATHAM (528 426) or email sales@latham-australia.com.