Learn how Sika’s bus roof bonding solutions can enable 90% faster assembly times with 70% less weight.

Now it’s possible to assemble bus roofs 90% faster with 70% less weight and just a fraction of the assembly staff. By bonding lightweight composite roof modules directly to the vehicle’s steel body, manufacturers can save materials, weight, and time, all while meeting the highest OEM safety and performance standards. Discover how Sika’s innovative adhesive assembly solutions can help you overcome the limitations of traditional mechanical fastening and move your business forward. In the fast-changing landscape of commercial vehicle manufacturing, design paradigms are changing. New hybrid platforms, large modular components and mixed-material constructions are all transforming the way vehicles are designed and built. At the same time, experienced welders are in short supply, while material costs continue to rise. Sika’s bonded bus roof systems tackle these challenges head on, enabling lighter buses that can carry more passengers while requiring less time, material and effort to assemble.

Sika Industry - Moving Forward

Accelerating Production

Traditional construction methods, such as welding, often entail prolonged production times and labor-intensive processes. For Van Hool, an independent bus manufacturer using traditional body-in-white design with several metal segments joined by welding and bolts, this amounted to a 24-hour production process with three shifts and several workers on the line. Instead of using six line workers to assemble and mount individual roof parts, Van Hool decided to explore the possibilities of a new structurally integral composite sandwich rooftop which could be mounted in a single piece. Standard adhesives were considered but were deemed unfeasible due to their short open time, which would require six workers to apply adhesives simultaneously, and long curing time, which would add up to twelve hours of unproductive waiting time. Fortunately, Sika’s specially formulated Powerflex and Curing-by-Design technologies eliminated these obstacles. Using cartridges or a pumping system, the adhesive can be applied by just one or two people. And faster curing means that subsequent assembly steps can continue less than two hours after mounting – amounting to a full 90% time savings.

New energy electric bus arranged in the workshop

Enhancing Performance and Safety

Unlike conventional adhesives, which are often compromised by thermal expansion in extreme temperatures, Powerflex adhesives offer heightened toughness and impact resistance across a temperature range of -40 °C to 100 °C. By uniting different materials and optimizing stress distribution, these adhesives provide consistent performance across a wide temperature range, ensuring flexibility at lower temperatures and stiffness at higher temperatures. As extensive rollover impact tests and FEM simulations clearly show, the result is a consistent improvement in structural crashworthiness (ECE R66) of the bus superstructure.

icon showing a building for facade

Sika Fenestration partner services include:

  • Construction consultancy: Review of existing systems for suitability for bonding and advice for system amendments
  • Functional testing: Support with prototyping, functional tests, system compatibility, adhesion and functional features• Application technology selection: Tactive consulting to select application and bonding technologing, systems and equipment engineering, and support for equipment application processes
  • Applicator training: Preparation of operation manuals for bonding/repair glazing for ISO compliance, together with customer service
  • External approvals: Best practice sample preparation 



Sika structural window bonding solutions enable:

  • Up to 20% improvement in thermal insulation
  • Up to 30% more light
  • Dynamic load enhancement, with increase of approved wind load by up to 10%
  • Up to 10% reduction in production costs
  • Up to 90% reduction in service costs
  • Up to 90% lower compliant rat