Where the tent roof got its name from is unmistakable. But this roof shape has long since made it into the circle of creative stylistic devices in residential building. It stands out from other roof shapes through some elementary advantages. We explain these differences and also provide numerous facts worth knowing about the tent roof.
Shape and origin
Of course, just because of the name, the relationship between the tent roof and the real tent is unmistakable. But the design is also visually reminiscent of the simplest form of the tent consisting of a central pole with a tarpaulin stretched over it. The first permanent dwellings in the form of yurts, simple huts and other forms of appearance also make use of this simple and effective roof shape.
There is a tent roof adapted to the usually orthogonally aligned floor plans usually made up of four roof surfaces with identical inclination, which are located in a central ridge point touch. This results in the almost inevitable square shape of a building covered with this roof. A circumferential lower edge of the roof reinforces the impression of a self-contained roof hood sitting on the structure. A popular nickname for residential buildings with a tent roof is, for example, "mushroom house".
The static structure
The shape with a central ridge point quickly shows that the tent roof, despite its visual proximity, has to follow a completely different static approach than that Gable roof:
1. Central ridge support
- Vertical transfer of loads from the ridge point to the solid components below (ceiling or wall)
- From every corner of the building from hip rafters to the ridge point as the upper support or connection point of the rafters
- Circumferential threshold as the lower support point
- Rafters as load-bearing elements of the roof structure of the individual roof areas
2. Purlin construction
- Circumferential threshold as the lower support point of the rafters
- Circumferential purlin as upper support, usually approx. a third to a quarter of the rafter length from the ridge point
- Upper rafter ends freely cantilevered to the ridge point
- Purlins loaded onto foundation components via columns or walls
3. Rigid frame construction
- Circumferential threshold as the lower support point of the roof structure
- Rafters from the building corners to the ridge point, mutually supporting, as a rigid frame construction without central support
- Rafters placed on hip rafters, or connected at the same level
Typical roof structures on a tent roof
In terms of construction, possible roof systems for the tent roof are based on the proven methodology:
- Inside: Vapor diffusion-tight layer against the ingress of moisture from the living space into the insulation layer
- Insulation layer
- Diffusion-open sub-roof for ventilation of moisture escaping from the roof structure, if necessary in combination with another insulation layer
- Rear ventilation level to remove escaping water vapor
- Outside: Roof skin with substructure
Ultimately, the tent roof has both common options for implementing this structure in relation to the supporting structure:
1. In-roof insulation
The insulation level corresponds to the rafter level. For this purpose, the insulation is inserted between the rafters as a soft insulation material. The respective delimiting layers are provided below and above the rafters. The optically visible inner ones
A cladding made of wood or painted, plastered or wallpapered plasterboard forms the end of the roof structure.2. On-roof insulation
The insulation layer is built up on the structural rafter layer and can be created either as a soft insulation between the timber or as a continuous, pressure-resistant insulation layer. As a basis for the insulation layer, a flat covering made of various wood-based materials must be built on the rafters. With this variant, the supporting structure remains visible in the roof space and can be optically staged.
NOTE: In contrast to numerous other roof shapes, on-roof insulation is very widespread on tent roofs. The reason for this is the high number of structural elements and detail points in the rafters that are too lead to a large number of fault points in the insulation layer when installed in the construction level would.
The roof pitch
Ultimately, a tent roof can be erected in all inclinations from 0 degrees. From a technical point of view, however, the construction only makes sense from around 10 to 15 degrees, as the attic space gained is otherwise mainly used by structural components. Tilts between 15 and about 30 degrees are common today. Larger inclines in the range of 45 degrees and more, on the other hand, create a voluminous roof space, which, however, is very difficult to use due to the inclination on all sides. In these cases, an alternative, more usable roof shape is usually chosen.
Roof coverings
A tent roof can be provided with almost any different roof coverings, depending on the roof pitch. Flat coverings should be given preference over, for example, bricks or shingles, especially on small roofs otherwise countless adjustments and cuts of individual bricks are necessary due to the burr details that can be found on all sides would be. Types of covering that can be found again and again are:
- Bricks and concrete roof tiles - mostly from 15 degrees, some models from 10 degrees
- Foil roofs - any roof pitch
- Gravel or green covering on the membrane roof - above 10 degrees only makes limited sense
- Slate, shingles and other local cover variants - mostly from approx. 15 to 20 degrees, depending on the substructure
NOTE: Since the tent roof in residential buildings has no noteworthy history, there are no typical, historical forms of cover such as straw, thatch or reeds.
Roof structures and installations
Basically, the individual roof areas of a tent roof are suitable for the construction or installation of dormers or roof balconies. However, the tent roof is in
Generally used with a rather shallow slope. Supplemented by the fact that the roof areas are trimmed on all sides, there is only enough roof area left in the case of very large-format roofs to sensibly place these structures. In practice, even skylights are rarely found on tent roofs.Differentiation from other roof forms
From a purely geometric point of view, the implementation of a real tent roof is actually only possible on square structures. In practice, it is also generally used for floor plans that are very close to the square. However, since a real square can only very rarely be realized for a variety of reasons, numerous special forms of the tent roof cover the building. Most of the time they are very similar to an extremely pronounced one Hipped roof, in which either the ridge line was minimized to zero with a different inclination of the hip and main surface, or the Point ridge of the tent roof with an identical slope on all sides, extended to a short, but linear ridge became. The exact demarcation of the tent roof from other roof shapes is ultimately difficult, but the naming is of secondary importance in terms of practical implementation.
Cost of a tent roof
A reliable comparison of the costs of a tent roof against other roof shapes is hardly possible. The reason is the common use of this roof shape. While independent lounges are often created in gable or hipped roofs, the tent roof often covers a full standard floor with room-high vertical walls. However, if one takes into account the other special features with regard to the floor plan requirements for buildings with a tent roof, this roof shape should at least be in relation to others Roof shapes in no way appear more expensive on the same building.
Advantages and difficulties
Of course, various aspects also have a positive impact on the tent roof, while other conditions are rather difficult:
advantages
- Good roofing otherwise difficult, square floor plans
- Due to the all-round inclination, the roof has a low optical weight - the roof shape appears to be very light
- Small attic volume, therefore a good solution without the need for additional usable space, without unnecessarily large amounts of dead space
disadvantage
- Great constructive effort
- Numerous points of detail and intersection
- hardly any roof structures or installations possible