Material list for a grain godown or PACS shed

The Central Warehousing Corporation's own specification for a conventional godown puts plain cement concrete under both the column footings and the panel walls, with brick or random rubble masonry in cement mortar above it, and reinforced cement concrete for the columns and the tie beam running around the walls at eave height. NABARD's separate scheme for a smaller rural godown keeps the plinth about 80 cm above the finished ground level and asks for a damp proof course at that level, so the floor stays dry above the surrounding earth.

Where the column is RCC, the reinforcement is TMT bar, tied and spaced to the site engineer's own design, and every bar of 8 mm and above carries the ISI Standard Mark under a BIS licence. SAIL SeQR is our first pick where a drawing names a brand of TMT, and the cement for the concrete around it comes off the same rack whichever grade the mix calls for. Where the column is steel, channel, joist, MS pipe or GI pipe stands on an MS plate base bolted into the same RCC footing, and the choice between an RCC column and a steel one belongs to the engineer.

NABARD's model scheme puts the roof on single span structural steel or tubular trusses, fixed on RCC, stone masonry or brick masonry pillars, at a stated height of 5.60 m from the floor to the tie level on a road fed godown. The Central Warehousing Corporation's own conventional design uses the same tubular truss on RCC columns and adds a wind figure to it: a truss built to the wind speed zone printed in the relevant BIS code, 33 to 55 metres a second depending on the location.

The angle, MS pipe and GI pipe that make a truss come off our structural steel and pipe racks, cut and drilled to a fabricator's drawing. The base plates and gusset plates at the joints are cut from MS plate or GP sheet the same way. What sits on the truss is the roof sheet itself, and the Corporation's own bill of quantities names it precisely: a precoated galvanised iron sheet of 0.55 mm total coated thickness with 120 grams of zinc per square metre, built to IS 277, the same standard behind the ISI mark on the GC and colour-coated sheet we sell. A small share of the roof, about 2 percent on the Corporation's own design, goes over in fibre sheet instead, to bring daylight into the floor below.

NABARD's scheme asks for the wall design to follow general masonry practice, brick or stone in cement mortar, built to keep its tensile stress within the cracking limit. The Central Warehousing Corporation's own design uses 23 cm brick or 38 cm random rubble masonry in cement mortar for the same wall. A steel-frame shed more often runs the roof sheet straight down the wall instead of building it in brick, and where that is the choice, the same GC sheet or colour-coated sheet stocked for the roof does the wall too.

The loading bay is where the vehicle meets the store, and the Corporation's own specification describes a rolling shutter of interlocked mild steel laths on a pipe shaft, wound by a set of wire springs, though its more recent designs use a steel garage door in the same opening instead. The shutter profile, the guide channel on each side and the spring inside the shaft are the three parts we stock for the rolling shutter version; a steel garage door is a fabricated item and goes through the same fabricator building the truss.

Nothing above is a design; it is where each part of a design comes from once one exists. A grain godown's column spacing, footing depth, truss section and shutter width all follow the span, the capacity and the soil the structure stands on, and those numbers belong to the site's own engineer before they belong to an order here.

Bring the drawing, or the span and the capacity if the drawing is not ready yet, and we work out which racks the job draws from and in what order the loads should leave for it. Cement, TMT bar and cover block for what goes into the ground first; channel, MS pipe and GC sheet for what stands up after it; shutter parts last, for the bay the grain actually moves through.