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.

Garden Trellis


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”.


Gitterpavillon_SanssouciTreillage 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.


Cheval de frise, a medieval latticed defense for anti-cavalry measure with many projecting long iron or wooden spikes or spears.

Stone Trellis Cage

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.

Iron grating over window Venice

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.

Puerto Rico Convention Center San Juan

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.

Game Nets



Post 226 – by Gautam Shah



Irons include range of materials, each of which with own unique properties. The Iron, technologically arrived in this chronological order, such as Wrought iron, Cast iron, Carbonized iron (Carbon steel) and (mild) Steel.

Wrought iron is composed mainly of elemental iron, with small amounts (1-2 %) of added slag (a by-product of iron ore smelting process consisting of a mixture of silicon, sulfur, phosphorous, and aluminum oxides). Wrought iron is highly malleable material, and so can be repeatedly heated and worked with forging tools to deform and shape it. Wrought iron gains strength when it is repeated worked. Wrought iron is softer and more ductile as contains little carbon than Cast iron. It is also highly resistant to fatigue, when large amounts of pressure are applied. Wrought iron structures pass through large deformations, before failing.


Wrought Irons are Magnetic, exhibit high elasticity and tensile strength. Wrought can be used for tension or compression (in comparison, the cast iron is suitable for compression only). First wrought items were Nails, Spikes, Clamps, Rivets, Chains, Tie rods (for arches and vaults), bulb-tees and I-beams. Other uses of wrought include, Fences, gates, grills, railings, balconies, verandas, canopies, statuettes, crests, and tools. Wrought iron is susceptible to chemical corrosion. Stressed areas are prone to cracking or chipping.


Wrought Iron lattices have been used primarily over windows, doors and other gaps. Latticed structures of wrought iron are used for balconies, as space dividers, church screens, vine climbers, stair railings, estate gates and barricades, frames for furniture items, lintels, beams, brackets, columns and for garden structures like orangeries and pavilions.

Iron forming reflects man’s innovative and craft skills. It has been a very difficult material to work with, as it presents different behaviour in its various forms. Yet, it has been cast, resealed, joined, spliced, chased and engraved. It has been reformatted with hot and cold treatments. Wrought iron has been used for household utilities, tools, vessels, arms, building elements, architectonic entities, decorative items and statuettes. It has replaced wood for its stability, strength and malleability.



Before the Middle Ages, wrought iron was used primarily for weapons, tools and utilities that only could be made with a metal. Unlike Cast iron, Wrought iron has a lower carbon content. It is stronger, non-brittle, and could be forged to any shape, and join by beating. Literally, Wrought iron means an iron that can be worked, both in hot and cold forms.


One of the most creative forms of wrought iron manifests in trellis, grills, and other hollowed or pierced-out planner forms. Earlier trellis or grills were formed of wood, bamboos, vines, and cast of copper or bronze, or even of ceramics. These materials were not amenable to plastic shaping. Wrought iron has been used as a plastic material to form variety of trellis, in simple or multi-curved planner forms and also mould sub-elements differently.

The first lattices were functional elements like the protective cover within gaps, and in doors and windows. Simple linear cast or forged elements were inserted in side structures of masonry or wood. These, however, soon became interlacing or entwined entities of bars, hot-forged or riveted forming a grill. Same techniques were used for creating grills for hearths and sieves.


Wrought Iron lattices began to be used 13 and 14th C windows of mansions and cathedrals requiring high security. Same structures were used as barricades and partitions. The lattices were designed with variegated shaping of bars’ profiles, and in terms of angle and spacing. Hot-forging and cold working methods were used to alter the sections and shapes of the linear elements. Round and square rods and bars were twisted, coiled and beaten into complex foliated forms. Iron pieces were chiselled, chased, riveted, shape forged. Iron plates were also used for plate like tracery elements. Ends, finials and cresting were cast from other materials like brass or bronze and mounted over steel roods. Riveting and hot forging was chief techniques of joint making. Joints, However, were so skillfully concealed that the grill seemed like one cast or formed piece.

Wrought ironwork began to serve other decorative purposes. Famous cathedrals and other public buildings ( Canterbury and Winchester Cathedrals of England and Notre Dame de Paris) have extremely crafty pieces wrought iron works.

21793578980_aed850cf69_cWrought Iron lattice work, began as a rough surface entity, but by end of middle ages, the surfaces were well formed, ground and joints were concealed. Surfaces were often chased, engraved, inlayed with materials. Finials, caps and other elements of brass, copper, bronze and gold were added. Ornaments were forged out as separate parts, and assembled with riveting, or welding. Decorative elements, such as of flowers, leaves, vines, birds, names, and coats of arms, were bunched or heaped to provide a composition language.





Post 200 –by Gautam Shah 



Grills are primarily protection devices in openings, but have been used as an ornamental element. Grills are placed in apertures, windows, doors, other gaps and also over walls. Grills are used barricades such as the as parapets on terraces, in balconies, galleries or at the edge of any elevated level. Grills are also used as transparent divider on roads and as estate boundaries. First grills were just heaps or stacks of twigs or thorny branches against any trespass-able opening. Fixed grills were created by or inserting wood sticks into the sides of the openings.

Reja Cathedral_of_Toledo,_1226_and_later_(9)_(29729883686)

Grills of stones or trellis are created in buildings. These Jalis provided protection and privacy. Metal grills of Bronze and Cast steel provided unbreakable and thin body material. The metals were shaped by casting, forging, bending and joining.

Sidi Sayyad Mosque .jpg


Grills of metal began to reflect the artistic fantasy, almost as close to a sculpture, mural or painting. It was possible to create many a different pattern. Grills had simple linear patterns of geometry as well as floral compositions. The lines of the composition were moulded into a planner (2D) or cubical (3D) profiles, by infinite sectional variations. The profile variations made the grill visible in different forms from different view angles. Grills themselves were initially planner elements, but now began to be moulded to form multi-curved surfaces and multi lateral 3D configurations like sculptures. A well-designed grill can be ornamentation yet be a functional entity.



Indian prostitutes peeking out from the doorways of their brothel - Lahore 1946

A predominantly vertical configuration in a grill pattern expresses a masculinity, heavy or solidity, and looks over bearing. It obstructs the vision through it. Vertical configurations in grills are psychologically associated with an enforced confinement or jail.


A predominantly horizontal grill pattern allows restricted, but wide horizontal level of vision, and so seems less masculine, solid or imposing. Horizontal patterns are too dependent on their surrounding elements to be effective, and as a result need lots of design co-ordinations.

St Peters


A curvilinear or floral pattern looks effeminate. Such grills arrest the vision into themselves, and so survive on their own. However, such patterns tend to be symbolic representations, and may seem out of place in any other context.


Grills are used to soften or harden the effect of other architectural elements. A semi circular stone arch bereft of any carvings or appendages can be made to look softer and less dominant by a suitable grill pattern. Similarly a flowing pointed arch or multi curved arch with flutes etc. can be made little more over bearing or imposing by geometric patterned grill.


Grills are used to divide very large open faces or gaps into visually manageable sections. Grills over Chowk areas in old Delhi and Northern India houses are used as walkways for accessing rooms across the Chowk and also for sleeping and drying clothes.

Latticed Roof





Post by –Gautam Shah



Grills and Trellis are used primarily for barricading, for providing a transparent vista and for ornamentation. Grills are placed in apertures, windows, doors and any other cleavages in the barrier systems. Grills are also placed against solid planes like walls for ornamentation. Grills are used as parapets on terraces, in balconies, galleries or at the edge of any elevated level. Grills are placed on level grounds to differentiate areas of landscapes and gardens, on walkways, roadsides, road lanes, etc.


Grills also incorporate railings and grab bars on walkways, stairs, ramps, passages, buses, railway coaches. Grills are placed as markers to differentiate acutely varied areas: between banks and water bodies such as rivers, canals, pools, puddles, between spectators’ and the spectacle, between slow and fast moving objects, against hazardous utilities like machines, ovens etc. Grills are used in nursery and infirm areas, where grabbing elements are required at many different heights.


Grills become gates, windows and doors. Grills also become ladders. Grills in vertical, inclined and horizontal positions are used as plant climber support, tree guards and to support pots and vases. Grills are used to hang clothes and to dry clothes.


Grills are used as spark arresters in fireplaces and against burners. Grills are used to support burning bodies in crematoriums. Grills are used to evenly distribute heat as in grilles and barbecue devices. Grills act as air distributors in A.C. rooms.

3479609858_db627dc1b5_zGrills by their typical configuration help in controlling, filtering, decelerating, directing, channeling things that pass through it.