Production building with BauBuche structure

Façade design

Above the transparent ground floor zone, the façade is clad with slate, the region’s traditional building material. The individual façade sections are tilted vertically at a range of different angles. The angle changes the way the sunlight hits the building envelope and the play of light and shadow intensifies the relief. This gives the façade its “craggy” appearance which, together with the anthracite-coloured material, alludes to the nearby Thuringian Slate Mountains. The narrow triangles created by the inclinations are offset with steel plates in the corporate colour green – a nod to the company motto, “elobau goes green”.

BauBuche load-bearing structure

The roof of the building is supported by roof trusses made of BauBuche. This type of construction is a so-called brace truss with additional support. The elements of the truss are subjected solely to tensile and compressive stress, so the high tensile and compressive strength of BauBuche make it ideal for construction with low-profile trusses and comparatively slender components. This provides an attractive, streamlined look with sufficient headroom for the installation of tall machinery and shelving. The top chords of the trusses are flush with the hall ceiling. The roof trusses are designed with a planned camber of 36 mm in order to reduce deformations.

Plan extract: merz kley partner ZT GmbH

Truss spacing	5 m
Columns	BauBuche GL70, 300 x 280 mm
Crane runway	BauBuche GL70, 180 x 360 mm

Roof trusses

Span	25 m
System height	1800 mm
Top chords	BauBuche GL70, 180 x 280 mm
Bottom chords	BauBuche GL70, 160 x 280 mm
Diagonals	BauBuche GL70, 160 x 280 mm
Vertical members	BauBuche GL70, 100 x 280 mm

Material comparison – BauBuche GL70 with GL glulam

	BauBuche GL70	BSH GL24
Top chords	180 mm x 280 mm x 25 m	240 mm x 360 mm x 25 m
Bottom chords	160 mm x 280 mm x 25 m	260 mm x 360 mm x 25 m
Diagonals	160 mm x 280 mm x 28,8 m	180 mm x 360 mm x 28,8 m
Vertical members	100 mm x 280 mm x 7,2 m	100 mm x 360 mm x 7,2 m
Material consumption per truss	3,87 m³	6,63 m³
Material saving	ca. 42%
Material costs per m³ *)	700,00 €/m³	450,00 €/m³
Material costs per truss	2709,00 EUR	2981,00 EUR
Material cost savings	ca. 10%

*) To calculate material costs, we have applied mixed prices (ex-works, without transport costs or trade margin) for a range of qualities.

The high strength values of BauBuche enabled material savings of 42% for this project, while the slender BauBuche components not only lent the building a more elegant look, but also made it possible to reduce material costs by 10%.

Truss junctions / connectors

The junctions and chord joints of the roof trusses were secured with dowels and slotted metal plate connections, with the steel parts completely embedded in the timber. This not only creates aesthetically pleasing junctions, but also considerably increases fire protection, as external steel parts lose their strength very rapidly in the event of a fire. Normally, the holes are drilled separately through the timber and the steel, which requires millimetre accuracy to ensure that timber and steel are subsequently a proper fit.

However, in this project, the problem was neatly side-stepped by using self-tapping dowels (manufacturer: SFS intec AG).

The multiple-shear steel-timber joints are created with extremely high fitting precision using a WS connector and a setting tool, The dowels are driven through both the timber components and the embedded 5-mm thick steel in a single process. We used dowels with a diameter of 7 mm.

Stiffening of the building / wind bracing

The stiffening of the building is achieved using wind bracing, which is likewise made of BauBuche GL70 beams. BauBuche GL70 beams are also used for the crane runway.