In 2018, the market town of Hard in Austria built a new school. Its interior is dominated by BauBuche. With a few exceptions, all floors are made in this attractive material, as is the post & beam construction. The community is delighted with the attractive uniform interior and also appreciates the durability of the flooring.
The three-storey building designed by the architects of Baumschlager Hutter Partners from Dornbirn (Austria) won the open competition in 2014. Completed in 2018, the building now houses the local primary and secondary schools. From the outset, it was the intention of the municipality to bring these two schools together in one building, as this arrangement would allow for tuition across classes and streams, in line with the Montessori comprehensive school model.
This idea is reflected in the general layout of the school that includes nine clusters dedicated to joint learning, each consisting of three classrooms, two group rooms, a staff room and a kitchenette. There is one such cluster at every floor in the three sections A, B and C of building. Wing D houses the school canteen, the assembly hall, administrative offices and rooms for teaching staff. The main building is thus designed in the shape of a comb and consists of a reinforced concrete frame construction with concrete cores. The transparent shell features post & beam web structures in BauBuche, complementing the flooring made of the same material.
Sturdy timber floor meets fire safety requirements
The proprietors insisted on timber flooring. To meet the statutory fire safety requirements, the hardwood floor needed to be at least 2 cm thick. When researching the options for such solution, the architects came across BauBuche. Given the exceptional strength of the material and its excellent hardness (Brinell hardness HB = 38.2 N/mm²), BauBuche met all criteria of the designers. BauBuche floors were therefore installed throughout the building in all classrooms, corridors and stairwells.
The architects also considered a hardwood flooring in ash and oak, but eventually opted for BauBuche, as they liked the attractive look of the material and its durability.
Joints compensating moisture-induced expansion
For the installation of the floors, the swelling and shrinking properties of BauBuche had to be taken into account, as the natural material is susceptible to moisture. The solution the architects came up with includes expansion joints fitted with cork strips.The main challenge in this context was finding the right number of joints to be installed in this way – as few as possible and as many as necessary – so as to prevent cracking or warping of the floor, while maintaining large smooth surfaces without visual obstructions. To find the best solution, the architects consulted the flooring contractor who was involved in the planning process from an early stage.
Traditional timber floor substructure
To support the 2 cm BauBuche floor, the designers opted for a timber underlay made from planks resting on beams, a floating construction method known from old buildings. The BauBuche boards of 11.2 cm in width and 2.2 m in length were then nailed to these planks. In contrast to a floor glued directly to a screed, the chosen construction allows for some yield and enhanced walking comfort, as the floor is "softer" to walk on. By opting for this substructure, the architects took advantage of a tried and tested timber construction method that befits the natural material of BauBuche.
At the same time, the floor surface is extremely durable and dirt-repellent. That is why the architects installed the BauBuche floor in all areas of the school, except in the bathrooms and the kitchenette. To protect the surface, the timber floor was sealed with a two-component oil-based product.
Cost-effective and ecological solution
The flooring works were included as a separate item in the best bidding process, and the costs of the flooring material was one of the key criteria. BauBuche trumped as the most cost-effective product.
The municipality obtained grants from the Austrian state and the government of Vorarlberg available for projects that meet the communal building certificate criteria prescribing minimum ecological standards for construction products. These criteria form the basis for the public funding of building projects in Austria. In the tendering process, compliance with these criteria must be proven in advance and the relevant specifications must be included in the submission. In addition, all material suppliers must also submit evidence that their products meet the criteria and that they are certified. Even the packaging of the products must meet specific criteria.
Very positive feedback
"We are very pleased with the BauBuche flooring in the school. It goes beautifully together with the BauBuche post & beam façade," says architect Ralf Bernhardt. "The homogeneous look of the BauBuche surfaces creates an interior of calmness."
This was exactly what the architects wanted to achieve, as the building was to form the neutral backdrop for the creativity and liveliness of the young students.
- Text by Susanne Jacob-Freitag -