Project Overview
The project was carried out as part of a wider estate portfolio, focusing on assessing and addressing structural defects in a timber gable truss.
The truss exhibited significant weather-induced deterioration and wood rot, compromising its structural integrity and ability to support the barn’s roof.
Site Investigation
A site visit was conducted in coordination with the farmer and asbestos removal surveyors to evaluate the condition of the truss.
The primary constraint during this assessment was the presence of asbestos-containing material in the lining behind the truss, which restricted access to certain structural elements.
Structural Assessment
Upon detailed inspection, it was identified that the timber truss had originally served as an intermediate support member. However, when the barn was downsized, this truss was repurposed as the end gable, subjecting it to increased exposure to environmental conditions. The deterioration observed was severe enough that the truss no longer provided adequate roof support, necessitating its replacement.
Initial Sketches
Proposed Solutions and Client Decision
A structural report was prepared, outlining the observed defects, their likely causes, and recommended corrective measures. The report included conceptual options for the replacement truss structure:
- Timber Truss Replacement – A like-for-like timber replacement, maintaining the original aesthetic and load-bearing function.
- Steel Frame Replacement – A steel-framed solution offering greater durability and requiring minimal foundation work.
After reviewing the options, the client opted for the steel replacement due to its reduced requirement for foundation excavation and lower overall disruption to the site.
Structural Design and Implementation
Following the client’s decision, structural design calculations were conducted for the steel frame replacement. The design included cranked elements, which posed geometric challenges but were necessary to align with the existing structure. Using Building Information Modelling (BIM), the final scheme was developed for submission to Building Control.
Outcome
The steel frame solution successfully replaced the deteriorated timber truss, ensuring long-term structural integrity while minimising onsite disruptions. The project was completed efficiently, meeting all safety and regulatory standards, and delivering a durable, low-maintenance structural solution for the estate.
Conclusion
This project highlighted the importance of thorough structural assessment and strategic material selection to address defects effectively. By leveraging BIM technology and engineering expertise, a structurally sound and practical solution was achieved, preserving the functionality of the barn while enhancing its durability.
