Post 476 –by Gautam Shah
The word Trellis derives from trilicius, (tri- + licium = thread), referring it to a woven entity ‘with three threads’. A trellis in old French as treliz simply refers to a fabric of open texture. Basket or matt weave is interpreted as construction where two or more threads of grass, weeds, vines, twigs, bamboo slivers or green cane slip are used in both the warp and filling direction. And so Trellis may have meant an open-mat like weave. These may have been used as screen cover over the gaps or openings like doors and windows, to prevent entry of stray animals rodents, flies, and mosquitoes, to reduce the pressure of heavy winds, or, control the brightness.
Matts have Three forms, soft ones have no edge reinforcement and so can be folded in either of the direction. Matts with reinforcement at the ends (usually warp ends) can be rolled up after hanging, whereas with stiff support on all four edges, it forms a panel. Trellises are referred to “as panels, made from interwoven wood pieces”.
Treillage is French word (Middle French, from treille or vine arbor) for latticework used for supporting vines and green foliage. Lattices have been used in agriculture for supporting plants, and protecting them in inclement weather. During Renaissance period lattices were key elements of garden scapes. These were used for gates, fences, tree guards and as support structures for pots and vases. For garden scapes metal trellises replaced the wood trellises, post-industrial age. A metal structure gets very hot and fast, burning out the climbers or plants, so wood has continued to be a compulsory requirement.
Lattices are architectural as well as interior space elements. These are of essentially of Five types.
1 Protective lattices against height related hazards, within openings, spiked one against unauthorized entry, and as spark arresters in fire places.
2 Space dividing elements such as fences, guard rails, reja (screens to enclose a chapel or a tomb in a church), partitions, and as a translucent barrier. Indian balconies, Zarokha and Mid-East countries traditional window form, Mashrabiya, use grills to occlude vision from outside and as a sun shading device.
3 Roofing elements are called Pergola or roof screens. Indian urban houses in crowded localities have central open cut spaces called Chowk, and these are covered with a lattice structure at every floor level. These are used for seating, sleeping, craft work, drying clothes, etc. besides providing lighting and ventilation to every floor. Pergolas are used to control the illumination and cutoff sunlight during specific daily and seasonal schedules.
4 Flooring elements of lattices are used in walkways and catwalks of warehouses, performance stages. Floor lattices in doors screen dust off the shoes soles. Floor lattices do not allow cattle to enter or leave an estate.
5 Structural Lattices are mainly used for reducing the mass (dead weight). Girders are castrated to increase the depth for the same mass. Brides, towers, pylons, Vierendeel Girders.