Fiber Expansion Material vs Nomaflex

By Marcus Kirkwood

What’s so exciting about expansion joint material, that we decided to write an informative blog about it? Well, frankly, pretty much nothing. But it’s necessary, so here we are, at your service, explaining the when, the why and the what of expansion joint materials.

The When

Expansion material is placed between sections of concrete. It’s that black stuff you see between concrete slabs sometimes if a contractor doesn’t put a sealant on top of it. If they do seal it, you’re likely going to see a grey sealant between sections of concrete. But don’t be fooled!! Beneath that beautiful sealant is something that can be compressed and expand in order to stop the concrete from doing that (because concrete can’t do that, it just breaks).

The Why

There’s not a whole lot more to it than the material itself acting as an expansion device for concrete or something other dense materials. The earth will forever move underneath whatever structures we create. As the earth moves, the materials above it move too. If those materials (concrete), have no flexion, they just break. You see broken or cracked concrete on every sidewalk you walk down. Expansion material puts a small pad between really hard materials giving them the chance to bend and not break as an entire unit.

The What

At Outpost, most of the expansion materials we offer are from WR Meadows. The most common expansion material is Fiber Expansion Joint. It’s composed of cellular fibers securely bonded together and uniformly saturated with asphalt to assure longevity. It’s versatile, resilient, flexible, and non-extruding. When compressed to half of its original thickness, it will recover to a minimum of 70% of its original thickness. WR Meadows also makes ceramar, rubber, plastic, cork and other materials that are used for the same purpose. This will, of course, depend on your application. So you stick to the original Fiber Expansion Joint, what’s the downside?

Well, there are a few. Namely, it’s a mess. Also, it snaps and breaks quite easily at times, and anything it touches will be black. In steps the next generation: Nomaflex. It’s even lighter than Fiber Expansion Joint. A small child could carry a bundle of it. Literally. And you get to ditch the zip strip. You just buy a cutter, and chop off that top ½”. Nomaflex is an excellent substitute for the original. In fact, it won World of Concrete’s Most Innovative Product in 2017. It meets ASTM standards D8139, D1751 and D545.

Whether you go the older, cheaper route, or the newest and most innovative, make your purchase at