Find the answers to some of the most commonly asked questions regarding architectural expansion joints; what they are, how to use them and more.

The answers to the most commonly asked expansion joint questions: 

What is an expansion joint?

An expansion joint is a purposely designed gap within a building that allows for expansion and contraction. Think about the gaps in-between squares on the sidewalk, those are expansion joints. Like the gaps in the sidewalk, buildings are broken into smaller portions as well.

In an architectural project, expansion joints are gaps within the structure that allow for thermal expansion and contraction, the moving and shifting caused by wind sway, and even the movement that follows seismic activity.

Why do buildings need expansion joints?

While it might not look like it, buildings experience shifting and movement every single day. Whether it’s due to high wind gusts, temperature swings, or maybe vehicular traffic coming and going from a connected car park – our buildings are moving and adjusting for these daily movements.

Buildings need to have architectural expansion joints to accommodate these movements and to prevent damage to the structure such as cracks and building degradation.

Do all buildings need expansion joints?

Yes – but to different degrees.

Buildings in areas of high seismic activity require much wider expansion joints, 12” + inches, some even as wide as 32”!

But areas with no seismic activity or smaller buildings, might only require 2”4” joint systems or masonry joints to accommodate thermal movement.

What is an architectural expansion joint system?

Architectural expansion joint covers are the engineered products that fit within your buildings expansion joint. Remember that some expansion joints can be anywhere from 2”-32” wide; now picture looking down that gap of the 12th floor of a hospital…I bet you’d prefer it covered too!

But architectural expansion joint systems do a lot more than just cover the building’s gaps, they are highly engineered to move with the building in all three directions and prevent the spread of smoke and fire when using fire barrier systems within the joint.

What are the different types of expansion joint systems?

Expansion joint systems come in many different varieties. Here are the main categories:

Within each category there is a ton of variety depending on material choice, fire rating requirements, widths, movement ratings, load requirements, surface or recessed options, etc.

How do I pick the right expansion joint system for my building?

  1. First and foremost, the easiest way to pick the right system for your building is to contact an expansion joint expert. Every building has unique needs that must be taken into consideration when selecting your architectural expansion joint systems.
  2. Consult with the structural engineer on the project. They’ll likely have a strict outline of the requirements the expansion joints need to meet.
  3. Finally, use your resources! Here is a free white paper that outlines the top six questions that architects should ask about expansion joints.


While these are some of the most frequently asked questions, we know that there are plenty more questions left unanswered. Please contact one of our expansion joint specialists to continue the conversation.


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