Processes for the plates

Processes for the plates

“Wood construction works best when the proportion of prefabrication is as high as possible,” says Jens Koch, wood construction expert at building materials manufacturer Saint-Gobain in Austria. This sentence reflects the new self-image of an industry that is currently reinventing itself. What was once limited to carpentry businesses and single-family homes is now an industrial process for large-scale residential construction - with a significant influence on all trades involved - including drywall construction.

Industrial production

“Austria has very experienced timber construction and prefabricated house manufacturers,” continued Koch. “In recent years, all providers have not only introduced innovations in products and systems, but also invested in their own production.” The result: Timber construction companies now work with industrial production facilities, processes have been simplified, and a lack of skilled workers has been replaced by new technologies.

The increasing level of prefabrication in timber construction not only changes the construction method itself, but also leads to a change in the planning, coordination and tendering of construction services. "What was once painstakingly installed layer by layer on the construction site is now pre-assembled in modern production halls. For drywall construction, this means a change from classic interior design to an integral part of the wall and ceiling elements," explains Koch.

In Austria, the proportion of new wooden buildings has increased significantly in recent years - especially in multi-storey residential buildings. Industrial prefabrication makes it possible for entire modules, including insulation, cladding and installations, to be assembled on the construction site within a few days - with virtually no waste or rework.

This also has an impact on drywall construction. “Drywall construction in particular shows how closely the trades are now intertwined,” says Saint-Gobain expert Koch. Instead of erecting one-sided planked frames on site, complete wall and ceiling elements with integrated drywall cladding are now produced in the factory. Sound insulation, fire protection and thermal insulation are no longer separate topics, but rather part of a holistic system. Koch: “The classic interfaces between timber construction, insulation and drywall construction are becoming blurred – in favor of greater efficiency and time savings.”

Saint-Gobain has responded to this development. A good example of this is the Riduro wooden construction board from the Rigips brand. It was developed specifically for the requirements of multi-storey timber construction and, with a 15 millimeter thick layer in the system with Isover Ultimate mineral wool, provides fire resistance of 90 minutes. This makes it possible to create slim wall structures that meet both fire protection requirements and static requirements - for example as stiffening walls. The panel is delivered impregnated and is also suitable for covered external walls and damp rooms - wherever no direct entry of water is to be expected.

In order to fully utilize the advantages of industrial prefabrication in timber construction, Saint Gobain expert Koch believes that the processes must be adapted. He criticizes the fact that, despite technical advances, planning in practice often still follows “the old pattern”. This starts with the submission planning. Often only a rough building envelope is designed, without precise information about insulation thicknesses, fire protection concepts or installation routes. Detailed planning only begins after the contract has been awarded to a general contractor - a procedure that is hardly practical in timber construction. "In the conventional construction process, detailed planning only begins when construction actually begins. That is too late for timber construction," warns Koch.

While in solid construction many decisions can be made during the construction phase, in prefabricated timber construction everything has to be decided in the early planning phase: from the statics to the installations to the specific product selection. “If a building is submitted in timber construction, it basically already corresponds to an implementation plan – whereas in solid construction it is only a rough plan,” says Koch.

In his view, this circumstance calls for a “radical rethink” among planners, architects and clients: the early determination of component structures, cable routing and material combinations is crucial in order to be able to use the advantages of prefabrication at all. “If you only start thinking about timber construction at the construction site, you have already lost the efficiency gain,” he says.

According to experts, the solution lies in greater integration of planning, prefabrication and execution – ideally in one hand. Companies that are able to deliver entire components or modules including all technical requirements can not only build faster, but also better control costs and quality. However, this also requires new forms of tendering. Instead of tendering out drywall, insulation and timber construction as individual trades as was previously the case, functional tenders are needed: a wall or ceiling element with defined requirements for fire, sound and heat insulation - regardless of how the provider meets them.

"In practice, we still often see misunderstandings. For example, when timber construction, drywall construction and building services are tendered as individual lots - even though they actually belong together," says Koch. “It would be much more efficient if detailed planning, prefabrication and execution came from a single source – as some construction companies with timber construction expertise already do.”

But the way there is still long. In many areas, the legal basis is still missing to be able to carry out functional tenders in a legally secure manner. Public clients such as cities or municipalities often still work according to classic tendering patterns, which prescribe awarding on a trade-by-trade basis. Koch: “I appeal to the authorities and politicians to finally adapt the regulations to the possibilities of the 21st century.”