Technical Insight: Roof Structure

As in previous stages of the Kashitu School project, we have once again implemented a proven structural solution for the new building's roof system — nailed timber trusses. These trusses, fabricated from locally sourced wood, are treated with a protective coating made from used motor oil to provide resistance against moisture and, more importantly, against insects — particularly the local "hungry" pests such as termites, which could otherwise compromise the structure within a short period. 

The trusses are supported by a reinforced concrete ring beam with dimensions of 300×300 mm, which is firmly tied to the vertical reinforcement (using Y12 rebar, with Y8 used for stirrups) in the corners of the perimeter walls, anchored into the cavities of interlocking bricks. The ring beam was cast into timber formwork, which was removed after curing. In some areas, mechanical surface finishing was required — removing concrete overflows with a chisel to create a smooth surface for subsequent installation of the roof structure.

The nailed trusses are then installed on the ring beam at regular intervals (spacing 2.1 m), forming the main roof framework. The trusses are anchored to the load-bearing structure using threaded rods and steel profiles.

Beekeeping Cooperative Facility

Each year, within the Kashitu School development program, a new facility with a distinct function is constructed — ranging from classrooms and workshops to this year's building, designed for a newly established beekeeping cooperative. The facility serves as a production and processing unit, with design emphasis placed on safety, indoor environmental quality, and operational efficiency.

From the users' perspective, three key requirements were identified:

• High-quality lighting of work surfaces
  

• Reliable electrical power supply for processing equipment
  

• Safe and hygienic indoor environment, protected not only from dust and humidity but also from bees, which can become particularly active during harvest season.
  

The issue of power supply and its continuous provision will be addressed separately in an upcoming update, as it represents a critical aspect of the building's long-term operation.

Clerestory Lighting – Daylight from Above

From the standpoint of occupational safety and health, natural lighting is a crucial design feature. The roof structure therefore incorporates a central skylight, providing clerestory (basilical) lighting.

This architectural principle originates from historic basilicas, where interior spaces were illuminated from above through a raised band of windows between two roof levels. The advantage of this system lies in its evenly distributed, diffused daylight without glare, enhancing visual comfort and reducing the need for artificial lighting during daytime hours.

For the beekeeping facility in Kashitu, this results in a more natural working environment, lower heat buildup, and reduced energy consumption. Artificial lighting will be strategically added above designated work areas to ensure safe and comfortable conditions during late afternoon and evening operations.

Conclusion

This year's phase of the project continues the long-term philosophy of implementing simple, locally feasible, and sustainable construction solutions, tailored to the region's material resources and climatic conditions.

The roof structure in Kashitu is not only a technical element but also an example of how traditional architectural principles can be adapted to modern requirements for safe and healthy environments.

The design draws inspiration from the clerestory lighting principle found in ancient and early Christian architecture — for instance, in St. Peter's Basilica in Rome, where the elevated central nave allows natural illumination of the interior. This concept has been reinterpreted within the contemporary context of Kashitu, adapted to local building conditions, much like modern educational projects across Africa (e.g., COF Outreach Village Primary Schools by Localworks, Uganda) that utilize natural light and ventilation to enhance indoor environmental quality.