Timber frame construction and its advantages
In recent decades, modern timber frame construction has been steadily gaining market share and set standards for energy-saving construction. Timber frame structures are found in single-family houses, multi-storey residential buildings and commercial and administrative buildings.
Timber frame construction is also well suited for renovation, heightening or extensions, thanks to its low weight and short construction time.
Advantages of timber frame construction:
- Optimal and resource-saving use of building materials
- Durable constructions due to the vapour permeable timber frame construction method
- Healthy living - thanks to natural moisture-regulating materials and high insulation standards
- The best insulation standards with low wall thicknesses reduce space consumption or optimise usable space.
- High quality and short construction time through extensive prefabrication
Structure types in timber frame construction
Timber frame construction is particularly economical if the design and structure are already adapted to construction grids optimised for timber construction at an early planning stage.
Typical and economical construction grids in timber construction are stud or beam distances of 625 mm or 833 mm. Depending on the building task and the desired degree of prefabrication, three construction methods are defined in timber frame construction:
Platform framingIn the case of platform framing, the walls are erected by storey, and the ceilings are also placed on the walls by storey. In this type of construction, large ceiling elements can also be prefabricated and placed on the lower walls at the construction site.
Balloon framingIf balloon framing is used, the walls are installed on two or more storeys first, the ceilings are placed in between the walls afterwards. Prefabrication possibilities for ceilings are very limited since the installation of large prefabricated components is rather complex in balloon framing.
Quasi-balloon framingAs a combination of platform and balloon framing the Quasi-balloon framing came up. The exterior walls of two levels leave space for the ceiling in between but are still connected. The significant advantage of this construction is the airtight connection between wall and ceiling. In addition, the Quasi-balloon framing allows a high level of prefabrication.
Static dimensioning
The static dimensioning of wood structures is carried out on the basis of the applicable national and European standards and building regulations. The basis is the EU Construction Products Directive (CPD), which is currently under revision and being transposed into a Construction Products Regulation.
EU-wide, the procedure for the design and calculation of timber structures is based on Eurocode EN 1955-1-1 2006: “Dimensioning and design of timber structures”. In EU Member States, an additional national application document (NAD) for EN 1955-1-1 may apply to dimensioning.
Characteristic values for Egger OSB and Egger DHF as a basis for structural design according to Eurocode 5 can be taken from EN 12369-1 “Wood-based materials – characteristic values for the dimensioning and calculation of timber structures”, building authority proofs of usability (e.g. European technical approval (ETZ), the General Building Authority Permit (ABZ) or the national application document (NAD).
Planning instructions
Compliance with the following planning instructions eases the procurement of the necessary board formats:
- As a rule, sheathing materials for timber construction are tailored to the grids e = 625 mm or 833 mm.
- The grid for the structure should only be established after the available panel formats have been determined.
- When sheathing is applied over a beam structure, the direction of the strong axis has to be taken into account for OSB (as a rule: orient the surface layer strands transversely to the direction of the beams).
- When sheathing is applied over beams, the panels must be connected on the beams, i.e. the available panel length and grid have to be matched in order to reduce waste.
- When specifying the panel size, apply main axis × secondary axis [mm], e.g., 2,500 × 1,250 mm, where the main axis of the OSB board is in the direction of the 2,500 mm length.
- We recommend ceiling-high sheathing for wall elements to reduce additional costs due to horizontal joints. As a guide, the minimum panel thickness for wall and bottom ceiling sheathing should be the panel thickness = span width (mm) / 50 in order to avoid bending.
Rule Details
Der Einsatz von Holz im Baubereich ist heute relevanter denn je, da Holz zahlreiche Vorteile für ökologisches Bauen bietet: Es ist nachhaltig, recycelbar, besitzt eine hohe Stabilität und ist wirtschaftlich zugleich. Um einen effektiven Brandschutz, Wärmeschutz und Schutz vor Feuchtigkeit zu gewährleisten, ist es wichtig, Details und Anschlüsse sorgfältig auszuführen.
Die in der Planungshilfe gezeigten Detailzeichnungen dienen als allgemeine und unverbindliche Empfehlungen und stellen einen Planungsvorschlag dar. Sie können jedoch individuelle planerische Detailvorgaben nicht vollständig ersetzen. Bei der Umsetzung sollten die projektspezifischen Rahmenbedingungen berücksichtigt werden und es ist ratsam, erfahrene Planer und Architekten hinzuzuziehen.