Fire Safety and Loctite HB X

Expanding Mass Timber Design Options with Loctite HB X

A new 12-story office tower in Rennes, France, and the Skypark Business Center in Luxembourg are two mass timber hybrid projects making industry headlines, even before they are topped out.

The projects are newsworthy not only because of their innovative designs and sustainability credentials, but also because of their demanding heat and fire performance specifications.

To help meet the challenge, the project teams chose mass timber made with Henkel Loctite HB X. The HB X formulation is suited for projects that require cross-laminated timber (CLT) and glue-laminated timber (glulam) with a fire resistance of greater than 60 minutes and self-extinguishing properties. Its fire and heat performance, specifically its charring rate, is close to solid timber.

Henkel Engineered Wood certified Loctite HB X in North America in 2018, which means it is compliant with the latest PRG 320 Standard for Performance-Rated Cross-Laminated Timber. The standard is known for its stringent heat and fire resistance requirements.

Now the same level of adhesive performance is available to mass timber manufacturers on three continents, thanks to recent HB X product certifications in Australia and Europe. 

Enabling Growth for Mass Timber Manufacturers

Henkel Engineered Wood expects HB X to accelerate a new generation of mass timber building designs in these regions. The expectation is not mere speculation. The trend is already well underway in the US market, where European and North American manufacturers using Loctite HB X are supplying an ever-growing number of large-sized projects.

Some prominent examples include Platte 15, an elegant 5-story retail and office building, which is the first CLT building to be built in Colorado, Carbon 12, a 26m tall luxury condominium in Oregon, and Adohi Hall, an award-winning 700-room student residence at the University of Arkansas.

Coming soon is Walmart’s multi-story and multi-building headquarters, featuring Arkansas-sourced mass timber material made with HB X. Also under construction is Ascent, the 85.6m tall luxury apartment building in Milwaukee, which will be the world’s tallest mass timber hybrid building when completed. 

The Premium Value of Henkel Engineered Wood Adhesives

While optimized for heat and fire performance, HB X has all the quality and productivity advantages that Henkel Loctite one-component polyurethane (1C-PUR) adhesives are known for. For example, quick, room-temperature curing, low coating weight, and zero adhesive-related formaldehyde emissions. 

“Henkel’s HB X is the first heat- and fire-resistant 1C-PUR adhesive to attain certification on three continents. Looking ahead to the next iteration of international standards, such as Eurocode 5, we wanted to make certain HB X products available in the interim,” says Olga Golgor, Head Market Strategy at Henkel.

Builders and architects now have more flexibility to realize their visions. Whether it is flexibility in the height of a mass timber building, the thickness of the wood elements, or the amount of visible wood in the interior spaces, project teams across three continents can specify products from the growing number of CLT and glulam manufacturers that are using Loctite HB X.