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What are the main repair procedures in buildings and civil engineering structures?
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4.2    Repair procedures – minor works
Wall cracks
•    Scrape all loose material around the damaged/faulty areas and fill open joints, broken areas with mortar (sand: cement at the 1:4). Wet the area before applying mortar, level the new mortar, and leave it for 15 minutes to get some strength before plastering to match existing plaster. Curing of the repaired areas shall be carried out for at least three days. Painting of the repaired area shall be carried out after curing period is over.

Shear cracks
•    Remove loose material, U-shaped steel hooks shall be fixed at regular interval along the length of the crack. Fill the crack with rich mortar, cure it for three days. Fix steel mesh on repaired crack and plaster it with sand cement ratio of 1:4. Level the plaster to match with existing one and keep the new plaster moist for an additional three days.

Paint work
•    All loose /damaged paint from walls/doors and windows shall be removed with the help of sand paper. Holes/damaged portion of the paint shall be repair using ready made putty available for the purpose. When repair areas are dried level the area using sand paper before applying paint. A commercial primer shall be applied to wooden doors/windows before applying paint. At least two coats of paint are to be applied;
•    school gates must be checked for smooth operation and if needed shall be painted;
•    rusty areas on steel doors and widows must be sanded off prior to applying red oxide paint as primer and applying two coats of enamel paint;
•    black boards must be refreshed with new paint;

Broken floors/foot paths/roofs
•    All broken portion shall be removed properly to the depth of leveling concrete (1:4:8) sub base. Wet the area and repair it with rich concrete (1:2:4) and level the repaired area to the adjacent floor level. Minimum of three days curing shall be carried out so that concrete shall gain 75% of its required strength;
•    plinth protection shall be repaired according to the procedure described for floors/foot paths;
•    while repairing roofs the roof slope must be checked to ensure that water will flow towards the down spout. Broken roof tiles shall be replaced and missing or broken pointing must be repaired and cured;

WatSan & services
•    broken toilet pans must be replaced and tested for smooth function;
•    broken air vent pipes shall be replaced;
•    broken & dripping taps shall be replaced with good quality taps;
•    broken tiles in bath rooms shall be replaced with new tiles matching existing tiles;
•    existing sewerage manholes must be checked by pouring a good quantity of water into one end of the sewer line while an observer checks the flow of water through the manholes. If detected, blockages must be removed/ repaired;
•    septic tanks must be provided with proper p-traps so that bad smell and back flow from the tank is avoided;
•    if the water network is leaking/broken, damaged pipes must be replaced with new lengths of pipe. Once repaired the network needs to be tested by pumping water into the system with the help of a pump or it should be connected to a water tank. The system must be kept under pressure for at least two hours. If no leak is detected or if there is no drop in the pressure of the network pipes shall be buried and connected to the water source.
•    damaged electrical wires must be repaired to national standard using proper fittings and joining equipment; safety of the building and occupants must be kept in mind;

4.3    Repair procedures – major works
Replacement of the entire roof
•    Badly leaking/broken/sagging roofs must be replaced provided that foundations and walls of the building are in a sound condition;
•    remove entire roof and repair and prepare the top of the walls prior to pouring RCC roof slab as per approved design. The roof needs to be designed by a qualified architect/engineer. After pouring, the formwork shall not be removed before 21 days, and the roof shall be cured for such period. Water proofing of the roof shall be done as per approved procedures adopted by government of Pakistan or per prevailing procedures in the construction industry;
•    where pre-stressed roofs are used, existing roof panels must be removed; existing beams shall be inspected by the manufacturer of the pre-stressed elements for their soundness and reuse.  The new pre-stressed roof shall be installed by the manufacturer. After installation proper water proofing of the roof must be carried out.

Replacement of floors
•    Remove damaged floor and debris and clean the area. Pour 4 inch thick concrete sub base (1:4:8), and cure the sub base for 24 hours. Pour the floor in rich concrete (1:3:6 or 1:2:4) in panels, cure it for at least 7 days. Depth of the concrete shall be adjusted to match existing floors.

WatSan & services
•    Blocked toilets system must be replaced and new floors and water closets installed;
•    The provision of a new water source for a building such as tube wells, pressure pumps and placing of new distribution network are considered major works and must be designed and installed by qualified engineers and installers.
•    Electricity: Unsafe/damaged systems need to be replaced to national standard by qualified installer. All cabling shall be carried in PVC conduits. Cables size must be used as per available load and proper panel boards to control the system need to be installed.