Taking safety measures

Jagvir Goyal.

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Every homeowner who invests his entire life’s savings in a home is worried about the security of the structure and of those living in it. Here are some necessary safety precautions that should taken to safeguard a house:

Fire proofing

All efforts should be made to make a house fire proof. An electric short circuit is the most common cause of a fire breakout in a house followed by leakage of cooking gas in the kitchen as the second reason. A short circuit occurs when two points in an electric circuit having a potential difference accidently come in contact with each other. Such an instance happens when insulation of the electric wires is of poor quality. It either gets damaged due to overheating of wires inserted in it or breaks down due to its own poor quality resulting in the wires getting naked and coming in contact with each other. Improper joints in wires which are not effectively sealed with good insulation tape also cause the wires come in contact with each other and cause short circuit. 

Leaking gas cylinders, faulty or duplicate regulators, leaking valves or improperly operating knobs of gas stoves allow leakage of gas resulting in breakout of fire. All these possibilities need to be eliminated by the house builder.

Essential electrical features

Use only ISI marked wiring of reputed make in your house. Choose copper conductor wires only. These are costlier than Aluminium wires but worth their cost. Choose electrolytic grade 99.97% pure copper wiring. This will ensure safety from short circuit and electric firing. Copper withstands heavier overloads. Prefer wires with three layered insulation and water resistant coating. Let there be plenty of circuits in your electric wiring drawings. This will also help in detecting the fault as only that circuit which carries the fault will get tripped. Plan a separate fuse for each power point. Use ELCB (Earth Leakage Circuit Breaker) in your house. It will trip on detecting a fault in the electric circuit and will keep on tripping until the fault is removed. Equip the electricity circuits of your house with MCBs (miniature circuit breaker). Use ISI marked MCBs of reputed make. A short circuit will trip these breakers instead of blowing the fuse. Check the electric load of your house and get equivalent or more load sanctioned from electricity department.

Essential earthing system

Provide good earthing system for the house and see that every electricity point in the house is connected to it. Use three-pin plugs for maximum appliances. Don’t save power bill by tampering with the earthing system. Earthing of the electrical system of the house is done by driving a GI pipe in the earth and connecting the whole system to it. The GI pipe is called earth electrode and GI wire is used to connect the system to it. A mixture of coal and salt is filled around the earth electrode to its full depth except a few inches at the bottom. The mixture of coal and salt keep the soil around the electrode wet permanently. Earth tester can be used to check the earth resistance. If earth resistance is more than prescribed value, treatment of earth electrode is required by increasing its size or depth. 

Gas leakage proofing: 

Bursting of a gas cylinder is no less than a bursting of a bomb. Arrangement for the location of gas cylinders should be planned in the front or back courtyard of the house by earmarking a protected and secure space for them. Concealed pipes are then run from the cylinders to the kitchen where a valve is provided to connect the gas stove to the embedded pipe. Care should be taken to ensure that the connection of the valve provided at the end of embedded pipe is leak proof. To detect leakage of cooking gas, a gas alarm can be installed in the kitchen. These days, many modular switch manufacturers are producing gas detector devices that sound an alarm on gas detection. Get one installed in your kitchen.

Fire extinguisher:  It is always better to install an all-purpose fire extinguisher at a suitable location in the house. These days, compact fire extinguishers are available and these are quite effective too. Care should be taken that these are kept well charged and are replaced before the expiry date. 

Protection against lightning

To protect buildings against damage by lightning, lightning arrestors are provided on the buildings. These lightning arrestors have many components like air termination rods provided at the top of building, down conductors and earthing electrodes driven deep into the ground.  

Bomb proofing

The idea of constructing a bomb-proof building had first occurred to the man during World War II. Increased number of attacks by armed infiltrators, terrorists and incidents like 26/11  etc have resulted in intensifying the research work on this front. Many research papers have come up. Use of polymer modified gypsum in construction is being thought of. The polymers used in it have a high degree of cross polymer linking that provides excellent defensive capabilities and three dimensional strength to the structure. Armorcrete is another material being experimented. 

However, choosing a bomb-proof design for a house looks unthinkable at the moment as it will prove highly uneconomical for the house builder. 

— The writer is HOD and Chief, Civil 

Engineering Department in a Punjab PSU

Earthquake proofing

Earthquake proofing of a house is not possible. No engineer will provide guarantee of building a completely earthquake proof structural design. Yes, he can design the house as an earthquake resistant one. The reason behind this is that the intensity of earthquakes is unpredictable. When the earth shakes, you don’t know to what extent it will cause the damage. The location of epicentre plays an important role. Though we have defined seismic zones for different areas, yet again these are based on past earthquake experiences and geological explorations only. An earthquake-resistant design shall, however, try to minimise the damage to the house during unpredictable earthquakes and save during predictable ones. 

Essential features: The design of a house must take into consideration the seismic zone and probable intensity of an earthquake in that zone. Zone V is the most earthquake prone and Zone II is least seismic. 

When a building has to be constructed in an area that lies on the border of any two zones, then the building needs to be designed as if situated in the higher seismic zone. Nowadays, the trend is to design a house for plus one zone. For example, if the house is located in seismic zone III, the design evolved is to resist the earthquakes for seismic zone IV. Earthquakes cause horizontal or lateral forces to act on the buildings, and buildings are designed by the structural engineer to bear such lateral forces and movements. Structural engineers choose to provide RCC-framed structure and RCC foundations for such buildings. Beam networks are created at different height intervals. Beams are chosen to be doubly reinforced to counter reversal of stresses. Columns are made stronger. 9 inch thick columns are avoided and minimum dimension of columns is kept as 1 ft. Provision of stilts for parking is avoided as it reduces the resistance of the structure in case of an earthquake.