Testing confirms mechanical performance of fixings in UK steel infill wall systems

Etex has released a third-party tested method for securing steel infill wall systems to fire-protected structural steel beams in the UK.

According to Etex, the solution has been tested for both mechanical and fire performance.

The testing was carried out by Remagin in partnership with Promat, with support from Siniat. All three brands are part of the Etex group.

The work focused on verifying that the fixings connecting steel framing systems (SFS) to protected structural steelwork maintain performance under load and meet fire resistance requirements.

Structural testing explored fatigue, movement and fixing strength

Remagin tested different screw types and configurations to understand failure loads and movement in systems where SFS heads are attached to boarded beams.

Introducing a board between the beam and the framing system can increase rotational movement and lead to additional stress on fixings.

To evaluate this, Remagin ran cyclic loading tests that simulated wind pressures typically experienced by SFS infill panels.

Richard Wilson, Technical and Specification Manager at Remagin, said: “Through comprehensive testing, Remagin has successfully verified the mechanical capabilities of fixings used in key scenarios to ensure continued robustness.

“Each fixing design is customised to the specific requirements of individual projects, and it is essential that the structural steel protection strategy and the SFS design are addressed as early as possible and coordinated well.”

Fire tests focused on maintaining compartmentation at connection points

Etex also carried out fire resistance testing on wall assemblies attached to encased structural steel.

Wilson added: “The fire testing demonstrated that fire integrity and insulation are maintained at the interface between the boarded primary steel and the wall system below.

“This testing provides confidence in the fire resistance capabilities of the holistic system to achieve performance through the complete elevation.”

He stated that the ability to conduct testing in-house across Etex brands supported a coordinated design and compliance approach.

Promat highlights risks with intumescent paints in steel-SFS interfaces

Promat UK’s Commercial Director, Joshua Slack, said that while intumescent paint is commonly used at the steel-SFS interface, it presents design challenges.

Slack said: “Complications can arise with this approach, firstly in ensuring the SFS and any required insulation allows space for the paint to intumesce.

“In addition, where the structural steel aligns with a fire compartment line the temperature needs to be kept lower than that which intumescent paints typically activates at.

“These factors should be reviewed on a case-by-case basis to ensure the best passive fire protection system is in place for the project.”

Slack stated that the collaborative testing programme would help design teams access project-relevant data and improve specification outcomes.

Third-party tested solution improves steel infill wall fixings: Summary

Etex has announced a new third-party tested solution for securing steel infill wall systems to fire-protected structural beams in the UK.

The mechanical performance of fixings was tested by Remagin using multiple screw configurations.

Cyclic loading tests were used to replicate real-world wind pressure.

Fire resistance testing was also carried out on wall panels connected to protected structural steel.

The project was conducted in collaboration with Promat and Siniat.

Richard Wilson from Remagin said project-specific screw designs were essential to maintain both structural and fire integrity.

Joshua Slack from Promat said that intumescent paints used at steel and SFS interfaces have limitations that require careful review.

He added that data-driven testing supports design teams in making informed decisions.

The work aimed to improve clarity around fixing performance and fire compartmentation where SFS connects to structural steel.

The solution has been positioned as a tool to assist accurate specification and reduce design risk.