Steel items (steel chogath, safety grills, steel stairs, main steel doors etc)
During the construction of grey structure, certain MS (mild steel) items are required at various stages e.g. Steel door frames (steel chogath), steel safety grills for window openings, steel stairs, steel main gate etc. Steel door frames and steel main gate are made from steel sheets that are available in different gauges out of which mostly used for these tasks are G14, G16 and G18. Lesser gauge value means heavier & expensive sheet. Other units used in making steel items are Steel Pipes, steel rods and angle iron that are measured in dimensions (width x breadth), diameter and thickness respectively.
Recommended sheets for steel door frames and steel main gate is G16. G14 sheets can also be used for main gates but due to heavier weight, it can cause imbalance in gate with time. Steel chogath can be made in two types of sheets MS(mild steel) sheets and GI(galvanised iron) sheets (“Jisti” in local language). Steel chogath made in GI sheets are a little expensive as compared to the chogaths made in MS sheets because of its corrosion resistant characteristic. Steel chogath should be fixed during brickwork of walls and special care should be taken for level and plumb line before pouring concrete to hold chogaths in walls. Before ordering steel chogath, it should be kept in mind that standard pressed sheets available in market for making steel chogath has a pataam (door stop) of 1.5″ by default that can accommodate 1.5″ thick door only during finishing. If you require a 2″ thick door, your steel chogath should have 2″ thick pataam (door stop).
Similarly in modern houses, stairs are also being built in steel structures instead of concrete. Steel stairs can be in different designs some of which are:
Safety grills for window openings are made of steel rods both in “ ( )½” and “()3/8 ” diameter. Safety grills made in ½” have more strength but come at a higher price as compared to other one. Steel pipes or angle iron are also used in safety grills at borders on four sides to hold the mesh of steel rods together. Dimension of border pipes should be 1” x 1” at least and in case of angle iron it should be 1.5″x1.5″.
Spiral stairs is essential steel item that is required almost in every house these days. Spiral stairs are used for accessing rooftops from rear passages of house. As shown in picture above, it consists of a main centre pillar that should be made of G14 steel sheet in 4” diameter. Hand railing pipe in 2” diameter and steps are made from angle iron and can be 2 to 2.5 feet in width as per desire. Make sure all the steel items are coated with red oxide paint to prevent corrosion. Main centre pillar should be properly grouted with concrete in soil for minimum 2 ft in depth along with steel bar supports and during fixing, special care should be carried out to make sure the centre pillar is in plumb line for full height. A slight mistake can cause whole stair to tilt in any direction. Other than a strong grouted base, supports should also be provide at every 10 ft and centre pillar that is hollow, should be filled with 1:2:4 concrete.