Addressing Design Discrepancies in Fixing Timber Wall to Steel Structures: An RFI Necessity

Author: RAJ (Arokiaraj Arputharaj)

Addressing Design Discrepancies in Fixing Timber Wall to Steel Structures: An RFI Necessity

When it comes to construction projects, precision and adherence to design specifications are critical. However, sometimes, practical considerations highlight the need for adjustments to those specifications. One such scenario involves the fixing of a timber wall to steel SHS columns and beams, where the original design calls for M12 bolts spaced 300 mm on centers.

The Issue with 300 mm Spacing

While the design specifies M12 bolts at 300 mm centers, this spacing is notably narrow for this type of application. Typically, such close spacing is reserved for situations where exceptional load-bearing capacity or additional structural support is required. In this context, a spacing of 600 mm on centers would be more than sufficient to secure the timber wall effectively, without compromising structural integrity.

The concern with the 300 mm spacing is not just overengineering but also the practical implications on the job site. Implementing such close spacing requires more materials, labor, and time, leading to increased costs and potential delays. Moreover, drilling excessive holes into steel SHS columns for fixing purposes could weaken the structural integrity of the columns, which is an outcome that must be avoided.

Alternative Solution: Gun-Fixing the Studs

Given that the primary objective is to secure the timber wall to the steel structure, an alternative approach could be considered. Gun-fixing the timber studs directly onto the steel columns, without the need for drilled holes, is a viable option. This method is not only faster but also maintains the strength of the steel columns by avoiding unnecessary perforations.

Raising the Issue: The Importance of an RFI

Before proceeding with the job, it is essential to address this issue through a Request for Information (RFI). An RFI will formally document the concern regarding the overly narrow bolt spacing and propose the alternative method of gun-fixing. By raising an RFI, the project team can seek clarification and approval from the design engineers or the client to adjust the specifications accordingly.

This step ensures that all parties are aligned, and any modifications to the original design are officially approved, reducing the risk of rework or disputes later in the project. It also demonstrates due diligence and a commitment to delivering a project that is both cost-effective and structurally sound.

Conclusion

In summary, while the original design calls for M12 bolts at 300 mm on centers to fix the timber wall to steel SHS columns and beams, this spacing is unnecessarily narrow. A 600 mm spacing would be sufficient, and an alternative method of gun-fixing the studs to the columns should be considered. Before commencing work, this issue must be addressed via an RFI to ensure that all stakeholders are in agreement and that the project proceeds smoothly and efficiently.