January 2, 2019


The term plumbing includes water supply and sanitation system. Water supply and sanitation is an essential service required for continuous supply of water and efficient disposal of water.


  1. Consultant
  2. Contracting agency
  3. Engineer
  4. All the necessary materials.


  1. Preparing layout of drainage and water lines with reference to existing drainage and water lines as per municipal norms.
  2. Approval from client and municipal authorities
  3. Design of OHWT, UGWT, Septic tank and distributaries for their capacities.
  4. Preparing of toilet layout, downtake and service lines.
  5. Monitoring the work at various stages as an when required and certifying the same.
  6. Getting the required NOC’s from the relevant authorities, after completion of the work.


  1. Detail study of drawing, verifying for feasibility as per site conditions and suggest necessary changes.
  2. Coordinating with consultant and site engineer.
  3. Make arrangement for men & machines as and when required.


  1. Study the existing water supply and drainage lines.
  2. Ensure that the concealed plumbing layout matches with tiles layout.
  3. Ensure the feasibility of concealed and external layouts, OHWT, UGWT.
  4. Day to day supervision & conducting different tests as required.


Ensure that all materials to be used are of approved quality and specifications.


  1. GI concealed plumbing on walls
    1. Mark the plumbing layout on the walls with respect to tile layout after completion of plaster .
    2. Use cutter machine for chiseling groves.
    3. Take measurements of required lengths of pipes, make a assembly of pipes as per layout. Fix it on the wall and ensure all heights and measurements.
    4. Apply coal tar to all pipes, asbestos rope for hot water line and jute cloth for cold water line.
    5. Fix the total assembly firmly in position.
    6. Check for leakages by pressure testing..

Pressure test:

  1. Plug the inlets and outlets excluding two end points where Pressure Testing Machine is to be connected.
  2. Apply pressure from the pressure pump. Ensure that the air in the pipeline is released completely. Develop the pressure upto 7 kg/cm2.  Keep the pressure intact, atleast for 30 minutes. Ensure that there is no pressure drop.
    1. After assuring that there is no pressure drop and any leakage from joints, finish the chiseled groove in cement mortar. Make the surface rough.
    2. Cure the finished surface atleast for 7 days.


  1. After the base coat of waterproofing is completed, fix the nahani trap/P trap and 100 mm C.I. bend in position as per drawing.
  2. The joints of nahani trap, connecting pipe, bend, P trap and connecting pipes should be sealed properly with cement and should be tested for any leakage before the next coat of waterproofing of the toilet.
  3. Place the G.I. outlet for basin and washing machine over the nahani trap with adequate slope. The outlet should rest on the nahani trap edge. Test the outlet for leakage.
  4. Curing should be done for cement joints. Proceed further with waterproofing work. . EXTERNAL PLUMBING LINES:

PVC soil, and waste water line.

    1. After completion of external plaster, mark all vertical lines on the wall in plumb as per layout and changes.
    2. Fix the C.I./ PVC pipes including specials, in line, level and plumb with proper clamping.
    3. Ensure that, all the joints are vertical .
    4. Ensure that all horizontal joints are leak proof.
    5. Minimum 3 clips should be fixed for every pipes, one at center and one at each joint. Fix the clamps using drill machine.
    6. All the connections below 1st floor level should be in C.I. pipes only.
    7. Connect 100 mm soil line to drainage chamber with proper slope and finishing.
    8. Connect 75mm waste water line to gully trap at ground level. Connect gully trap to drainage chamber with S.W.G pipes in proper slope and finish.

Antisyphonic lines: –

Antisyphonic lines are provided to release the traped air and foul gases. These lines are to be fixed as per the procedure followed for 75 mm and 100 mm lines given above.

Rainwater line: –

Purpose of rain water line is to drain out the water from top terrace, individual terraces, and balconies.

    1. Rainwater outlet should be fixed considering waterproofing level.
    2. Vertical line to be done as per the procedure of C.I./PVC lines given above.
    3. Provide shoe at parking level 6″ above FFL.
    4. Rain water to be drained through rainwater gutter to rain water-harvesting system.
    5. Do not connect rain water line to drainage chamber.

G.I. down take:

    1. Mark all the G.I. lines on the wall in plumb as per layout and design, after completion of external plaster.
    2. Fix all the vertical G.I. pipes in line and level with proper clamping.
    3. Minimum 3 clamps should be fixed one at center and one at each joint for each pipe. Fix clamps using drill machine only.
    4. Ensure that all the joints are watertight.
    5. Provide control valves/ pressure valves as per design.
    6. Provide control valves for all toilets, kitchen and master valve at terrace level as per design, location and specification.

Terrace :

    1. G.I. work on the terrace should be done after waterproofing of the terrace is completed.
    2. It should be laid as per given layout and design.
    3. Preferably terrace looping pipes to be run 0.6 m above the waterproofing level, on the parapet wall with clamping.
    4. Ensure that outlets from OHWT including fire fighting outlets are fixed before waterproofing.
  1. Supply of water to and from under ground water tank:
  1. Before doing the roadwork, lay the required water supply lines from the source such as, municipal line, bore well, open well , treatment plant,  up to the underground water tank.
  2. Lay the delivery lines from UGWT to OHWT .
  3. Check the positions of delivery lines, air vents, wash out, drain pipes, manholes for both the tanks.


A network consisting of collecting chambers, drainage lines and sewer trap chambers for collecting and disposal of excreta and waste water, in a hygienic manner is known as a drainage system.

A] Collecting chamber: – These chambers collect the wastewater and excreta coming from the down take lines.

Soil pipes are connected directly to the collecting chambers where as the wastewater lines are connected to the collecting chambers through a gully trap chamber.

B] Inspection chambers: –

These chambers are provided wherever the direction of the line changes. For straight lengths, the chambers shall be provided at an interval of 15 meters for 150mm line and 30 meters for 250mm line for the purpose of Inspection..

C] Sewer trap chamber: –

This is a well-designed trap, which connects the internal drainage system to public drainage/ septic tank. The purpose of fixing sewer trap in a chamber is that, it has a deepwater seal to prevent foul gases from entering into line in case of choke up.


  1. Drainage line to be constructed as per the design and layout.
  2. Excavation to be done considering the invert level of chambers.
  3. Drainage line should be laid in straight line and the length of the chamber should be parallel to the flow.
  4. The line should be laid on well compact and firm base.
  5. Minimum slope for 150mm diameter drainage line should be 1:100 and for 250mm diameter line it should be 1:200.
  6. The joints of the collar should be packed with packing rope, soaked in cement slurry and sealed with rich Cement mortar to the cemented joints.
  7. Proper curing should be done atleast for 7 days.
  8. Construction of collecting chambers, inspection chamber, manhole, drop chamber and sewer trap chamber should be done, as per the requirement.


  1. This test is carried out between two consecutive chambers/manholes.
  2. Lower end of the drain should be plugged with rubber stopper.
  3. Fill the upper end of the drain with water by funnel. The funnel should have a head of 0.9 meter.
  4. Plug the upper end of the drain and pass the funnel through it.
  5. Wait for 2 hours.
  6. Check the level of water in the funnel. If there is any drop in water level, it indicates the leakage in the drainage line.
  1. Carry out back filling work only after ensuring that there is no leakage in the line.
  2. Place the chamber cover of Medium duty or Heavy duty as per the requirement.


  1. Indian W.C.: – It is to be fixed on ‘P’ trap which is built solid with brick and cement mortar up to the rim of the W.C.pan.
  1. European/ Anglo Indian W.C.: – EWC is fixed after toilet flooring is completed and on the bend provided in case of ‘S’ trap.

In case of ‘P’ trap, the outlet is connected to the external lines by the connector through the wall. Wall hung commodes are fixed on brackets which are fixed on walls & the legs of the bracket are embedded in waterproofing.

B] Wash hand basin: –

The wash hand basin is fixed firmly on a pair of brackets. Brackets are fixed in line & level with fasteners.


All the C.P.fittings (Wall mixers, bib cocks, angle cocks, basin mixers, showers etc.) should be fixed only after all the other works and the cleaning work is completed. It is the last activity done before handing over possession of any unit.

  • All the fittings should be fixed firmly and checked for leakages.
  • Proper precautions should be taken to see that the fittings shall not be damaged by the tools used for fixing.
  • C.P. fittings should be fixed by a skilled plumber only.


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