Hexayurt reciprocal frame roof options.

The walls of the Hexayurt shelter could provide an ideal base for a reciprocal frame roof with significant advantages for beneficiaries and Aid Agencies.

Improved ventilation, a cooler shelter, reduced transport costs and, importantly, the use of sustainable materials such as bamboo are just some of the advantages of this option. It also offers an opportunity to use standard tarpaulins if available.

The following diagrams and models illustrate how this option could work.

hex poles
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6 poles are overlapped reciprocally on the ground and lashed together. Bamboo, wood or steel tent poles can be used.
It is not necessary to determine the exact dimensions of the central hexagon or its symmetry at this stage as adjustments can be made after the frame is lifted onto the hexayurt walls.

In this model each wooden beam supports its neighbour.
This creates a self-supporting roof frame.

Hexayurt roof option -side

The incline of the roof is determined by the size of the central aperture required and the diameter of the beams

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In this model the aperture is small and the beam diameter relatively large, making a higher inclined roof.

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In a transitional shelter this central aperture has distinct advantages for ventilation.

As the structure is self- supporting, the weight of the roof is exerted vertically downwards at the pole ends and there is less " outward spreading" forces on the walls.

Hexayurt roof option - Copy 4
Hexayurt roof option - Copy (6

If wooden beams are used the standard Hexayurt wooden triangular roof panels can be used.

Alternatively, as in this example, two tarpaulins can be used instead of 4 of the panels, with the remaining 2 panels being used to seal the roof as shown below.

Hexayurt roof option - Copy (7
Hexayurt roof option - Copy 12

The two tarpaulins are now secured by 2 overlapping roof panels. The great weight bearing strength of the reciprocal frame means that additional reeds, grass or bamboo can be added at a later date to cover the tarpaulin if required making the shelter even cooler.

Hexayurt roof option - Copy (10
Hexayurt roof option - Copy

The central aperture is ideal for providing additional light and ventilation. It can be capped in various ways; the simple rigid panel shown here allows cross ventilation and some lighting. In a cold climate the central aperture is ideal for a stove flue.

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In this model of the roof a simple cap sits on top of the frame providing good cross ventilation through the side apertures.
In the tropics this cap can be removed most of the time and simply tied in place when required.

Hexayurt roof option - Copy (15
Hexayurt roof option - Copy 16

A single tarpaulin could be used in an emergency and secured at the centre with a rope tied horizontally around the aperture

Advantages of using a reciprocal frame roof for the Hexayurt.

The hexagonal frame of the Hexayurt provides a very strong foundation for mounting a reciprocal frame roof. In return the RF roof offers the following advantages for Hexayurt construction:
 

  • Strength of reciprocal frame for load support.
    • This allows the use of locally acquired heavy insulating materials. In the tropics covering with reeds, grass or bamboo makes the shelter cooler. In a cold climate insulation is provided by a deep layer of snow.

      •  Simple construction, no special skills required .
        • The joints are cross-lashed together with twine or rope. The roof weight is transferred vertically at the points of support with minimal spreading forces; this makes for easy attachment at the walls during assembly.

          •   Improved ventilation.
            • Central cross ventilation through roof. The roof could also be supported at each corner with posts that can lift it a little above the side walls to provide additional ventilation.

              •  Option to use tarpaulins.
                • The roof can be completely, or partly covered with standard relief tarpaulins. The tarpaulins can then be covered with available materials for additional insulation if required.

                  •   Option to use bamboo.
                    •  All main components of roof can all be made of bamboo if available.

                      •  Option to use steel poles.
                        • This is mainly for shelter kits with tarpaulins when available. Steel is becoming increasingly attractive for durability and ability to be recycled into more permanent constructions.

                          •  Reduced weight for transportation (more economic for Aid Agencies).
                            • Savings on weight and volume for transportation especially if local materials can be used to complete construction.

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