Not All the World’s a Stage — Planning the Stage Floor
What must be considered when planning a stage floor?
Properties of the Stage Floor
A stage floor literally forms the foundation for all work on stage. It must be able to bear heavy loads without creaking under them. It should be black and non-reflective, as if it were invisible. Overall, it is expected to be unobtrusive while remaining remarkably durable. The stage floor forms the upper surface of the underlying machinery and ensures a uniform level across all areas of the stage. The stage floor is probably the most underestimated component in a theater, as its planning, manufacturing, and installation demand a high level of expertise and craftsmanship.
Stage Floor — Choice of Material
The high-quality woods required for stage use are expensive and only available in limited quantities. To achieve a wear-resistant stage surface, a vertical grain orientation (quarter-sawn) is essential, which requires sufficiently thick and aged timber.
Hier ist die Übersetzung ins Englische:
Oregon pine was used in the 1970s as a substitute for pitch pine, which had long been unavailable in Europe. However, commercially available Oregon pine increasingly no longer exhibits the original, well-known strength, resulting in a comparatively short service life. Since 2016, the price of Oregon pine has risen dramatically due to the near-complete logging ban in the USA. It is now only obtainable from certain regions in the USA or from Canada.
Hier ist die Übersetzung ins Englische:
Pitch pine has been used as stage flooring for over 100 years and combines all the properties necessary for theater operations. Its surface is extremely hard, the wood remains resilient due to its high resin content, and it hardly splinters. At the same time, it is easy to screw and nail, and it withstands stage traffic almost indefinitely. Pitch pine comes from Canada, the southwestern USA, and Central America. However, long supply chains and limited availability affect the cost of a pitch pine stage floor.
Hier ist die Übersetzung ins Englische:
Scots pine is a domestic wood that is nearly equivalent to pitch pine. The harvested logs are thick enough to allow rift sawing. Resin content, density, and strength are comparable to those of pitch pine. Unlike pitch pine, Scots pine is more readily available. Consistently high quality and short supply chains are ensured. Due to its fast growth and relatively short reforestation cycles, the use of Scots pine can be considered particularly sustainable.
Plywood or beech multiplex panels are generally not suitable for use in performance areas of theaters, as these panels cannot be screwed or nailed and their surfaces can only be sanded to a limited extent. However, outside performance areas, for example in pure transport zones, storage areas, or elevators, they can be used. In these cases, advantages include higher load capacity and a lower price.
Planks vs. Panel Material
The “classic” stage floor was still constructed as a plank floor until about 15 years ago. Here, 40 to 60 mm thick solid wood boards with tongue and groove were milled and glued together.
From an ecological standpoint, plank floors are no longer justifiable today, as the wear layer comprises only about 20 % of the high-quality and rare wood.
Furthermore, the demands of stage operations regarding load capacity have increased significantly over the years. The use of floor transport vehicles (such as forklifts or aerial work platforms) on stage results in high point loads, which a plank floor can no longer support.
For these reasons, panel material has replaced planks. Panels usually consist of a plywood core, a usable top layer of pitch pine or Scots pine, and a back layer also made of plywood. The top layer has a thickness of about 8 to 10 mm, which is sufficient to allow the stage floor to be sanded multiple times over its lifespan. This ensures that valuable wood is used sparingly and optimally.
Panel material can be installed more quickly than planks due to the large, continuous surface areas. When used on under-stage machinery, factory-prefabricated, precisely fitted panels are often possible, eliminating the need for on-site cutting.
Stage Floor – Construction
The substructure (support timbers) is screwed either to the raw floor or – in the case of stage technical steel and machinery – to the supporting beams. If required, measures for impact sound insulation can also be implemented in the area of the substructure.
The support timbers are leveled with millimeter precision; they provide the new stage floor with accuracy in form and position. For low construction heights, stage floors can also be laid on a filling layer instead of support timbers.
The panels are laid on the support timbers so that the grain of the top layer runs parallel to the front edge of the stage. They are screwed from above into the support timbers, countersunk, and the drill holes are closed with crosswood dowels, which can be sanded together with the stage floor.
Wear-prone edges of the floor (e.g., in the area of stage lifts) can be equipped with angled hardwood strips. These can be replaced by the operator themselves when the wear limit is reached.
Often, connection points for lighting and audio technology are located beneath the stage floor. To allow access when needed, floor hatches with appropriately designed cable feedthroughs are provided. By arranging such hatches in series, cable ducts can also be created, allowing temporary, production-specific cabling to be hidden under the floor.
Stage Floor – Installation Conditions
Stage wood has a very low moisture content of a maximum of 10 %. To prevent the wood from absorbing moisture from the environment during installation – which it would later release, causing shrinkage and cracking – certain climatic conditions must be observed. This is especially important on construction sites where unfavorable combinations of low temperatures and high humidity can occur. Humidity and temperature must therefore be continuously monitored during the construction phase and adjusted as necessary.
Stage Floor – Surface
The surface of stage floors can be finished with oil glazes or water-based PU paints. It is important that the paints used are approved by building authorities. Glazes are less susceptible to damage from adhesive tapes, while PU paints can be applied more quickly, are non-glossy, and more resistant to abrasion.