Profiled timber elements – the smart solid timber units

Bild: Petzenhammer Architekten
Bild: Petzenhammer Architekten

The all-rounders for interior finishing and external structures

Profiled timber elements (PHE) complement the Massiv-Holz-Mauer® (MHM) walling system by forming the roof and ceiling components and thus making it possible to manufacture the complete structural shell of a residential building out of solid timber.
What is more, these board stack elements can also be used as solid, large-surface components in all areas of timber construction regardless of the MHM construction method. The solid timber PHE elements are made of multiple rows of 24 mm-thick softwood boards joined together by fluted aluminium nails. Details of the technical properties and dimensions can be found here.

Profiled timber elements are especially suitable for refurbishing or renovating old timber supporting structures and trusses because in such cases the load-bearing components (e.g. ceilings) can be constructed layer by layer without over-stressing the existing supporting structure by weight, shocks or opening up the outer shell. Ceilings made of PHE elements can be walked on immediately after manufacture, which is a definite advantage both in new buildings and refurbishing work.

Advantages of PHE solid timber elements at a glance

  • Unique value for money: minimal planing and trimming losses – only around 5 % depending on wood quality
  • Glue content is kept to a minimum
  • Moderate component thickness reduces thickness of floor/ceiling
  • Pleasant surface temperature improves interior atmosphere
  • Tested sound levels and strength parameters
  • Well-rounded – PHE units can be manufactured with a certain degree of widthways curvature so as to create a rounded building corner, barrel dormer or curved shower enclosure.
  • Choice of soffits – V-chamfer or acoustic profile
  • Minimal warping due to thin 24 mm board layers
  • Can be used as highly fire-retardant building component (M-HFHHolzR)

Surfaces of PHE profiled timber elements
The PHE elements can be produced with a number of different surface qualities. If the surface is to be visible, wood colouration and knotting is reduced to a minimum. A precise definition can be agreed with the PHE manufacturer concerned prior to production. In addition, the shape of the surface can also be modified. The unique production process and the use of 24 mm-thick softwood boards creates thin, understated, line-like laminations in the finished profiled timber element. A V-chamfer between the individual laminations or the patented PHE acoustic profile can be machined.
The V-chamfer is used to create a discreetly textured, virtually smooth surface when installed.
The patented PHE acoustic profile produces a less smooth surface that has sound deadening properties.

Sound insulation using PHE profiled timber elements
Building plots and sites are becoming smaller and smaller; distances between buildings are shrinking. Multi-storey and multigenerational houses are the trend. Due to the resulting increase in noise from the outside or the apartment above, good sound insulation is enormously important (especially footfall sound insulation of ceilings). PHE elements have a high basic mass with a relatively thin ceiling thickness. Mass is extremely important in terms of footfall sound insulation and vertical airborne sound insulation. In that respect, PHE elements have an enormous advantage over conventional frames of joists. In addition, there are certified ceiling structures and sound levels for PHE elements.

Further enhancements to meet higher sound-insulation requirements, for instance, can be achieved by means of a suspended ceiling soffit (gypsum board, timber formwork and spring washers) and well-designed details (ceiling bearing points). To obtain good sound insulation from a ceiling, the separating ceiling itself should not be viewed in isolation – instead, the secondary sound transmission paths should also reduced.
You can find the details in the planning manual available free of charge from our download area.

Structural load capacity of PHE timber elements
Fundamentally, the structural load properties for general applications are verified according to Eurocode 5 (EC5). EC5 is a standard introduced in the EU for carrying out structural load calculations in timber construction. All structural load verifications for PHE elements, e.g. for ceiling diaphragm, vibration, point loads and transverse distribution, should be carried out by a suitably qualified person or the manufacturing plant.

PHE as wall element
As the solid timber wall (and other wall construction systems) are generally lined with boarding materials, PHE elements can be used as wall elements that are exposed on one side. However, it should be clearly determined at the planning stage where electrical wiring and other installations are to be placed in the exposed walls.

PHE as roof element
Especially in the heat of the summer, occupants can find themselves wishing for pleasant and cool loft and attic floors. To achieve that, builders must aim at creating roof structures that offer long phase shift times. Solid timber, which is what PHE elements are made of, provides the best possible basis for achieving long phase shift times. In addition, the roof soffit is immediately finished when using exposed profiled timber elements in the interior. The developer or architect can concentrate on other trades.

Detailed solutions
You can download the connection details for the profiled timber elements here.