Expansion joint covers are exposed to a lot of abuse every day from frequent pedestrian and wheeled traffic moving across them as well as strong building movement forces pushing or pulling on them regularly.
Construction Specialties - CS has listed out five of the most common issues associated with existing, already installed expansion joint covers, along with causative factors.
Cover Warping
Expansion joint covers may warp due to incorrect specification prior to installation, with the architect selecting a standard duty model for an area where a heavier duty model was required.
An expansion joint cover will generally warp due to excessive point loading; therefore, it’s important when specifying an expansion joint cover, to check the point load capability of the cover, and installing a heavy duty option if required.
Finishes Cracking
Expansion joint cover finishes such as gaskets will often crack if the building movement has exceeded the expected limit, with the expansion joints generally expanding or contracting beyond their design. Gaskets or cover plates could also begin to crack if the load capabilities are exceeded, putting too much pressure on a certain point.
A structural engineer can be consulted at the time of specification to ensure the joint being specified will be able to cope with the expected building movement; also discuss with the end user what type of traffic would be moving across the joint after installation.
Becoming a Tripping Hazard
Improper installation can turn expansion joint covers into dangerous trip hazards. This can happen when the blockout hasn’t been created properly, causing the expansion joint cover to rise above the floor finish. Joint covers can also become a trip hazard if they become damaged from excessive movement or weight being applied to them, causing the cover or gasket to buckle and warp.
Ensure at the time of installation that the contractor on site understands the importance of the blockout being produced correctly, and the end user understands the point load requirements of the joint cover.
Excessive Noise
Excessive noise from an expansion joint cover is usually a sign that the internal gasket is either missing or damaged, causing the internal metal workings to scrape together. It’s also possible that some of the screws holding the cover plates together may have loosened over time.
Double-check that the exposed screws are tightened correctly; if this doesn’t resolve the problem, replace the joint covers.
Leaking Water
Water leaking through an expansion joint cover can often be attributed to poor blockout conditions and water actually leaking through the adjacent concrete. Also check whether the moisture barrier has been installed properly, and that any joins or splices in the membrane have been done correctly.
Construction Specialties - CS offers a wealth of experience with expansion joint covers, from specification and identification of the right cover through to installing them on site.
