BUILDING SERVICES

UNIT – II
PLUMBING WORK
Contents To Be Learnt:
Water Supply Provisions

Sanitary Provisions

Accessories of Sanitary

Plumbing Methods

Problems with Plumbing work

Water Supply in High Rise Buildings

 Water Supply/Distribution Provisions
How best a building might have been planned and built; it is incomplete till

adequate building services are not provided to it.

• Provision: Providing or supplying something for use.

• Sufficient quantity of water is provided to the building for the needs such

as drinking, bathing, washing of cloths and washing of floors.

• More quantity of water is used through sanitary fittings like water closets, wash basins, sinks, bath
rooms etc.

• After use of whole water, the water gets polluted and has to be drained off through the underground
drains.
• Water supply to water closets; bath rooms, wash basins, kitchens etc of a building is
provided through water supply pipes from municipal water mains which run along the
streets.

• Over head water storage tanks are also connected to municipal mains through pipes with
the help of ferrule Water closet.

• A ferrule is a connection from the main system or your

water distribution system to the individual buildings

or individual houses that's what we call it a ferrule.

• Requirement of water for residences should be assumed as 135 liters per head per day.

• From municipal mains to house, the pipe line may be buried underground by arranging
elbows, clamps, sockets, bends, bib-taps, check nut/ unions, gate valves/ball valves etc..

Sockets
 Bends Unions

• A water distribution network consists of pipes with appurtenances and it transports

water from the treatment plant to the consumers tap.
 Distribution Methods

• In gravity system, distribution reservoir at a very high level and your distribution
area is at a lower level, and all the water flows to the distribution area by gravity.
Advantage of Gravity System: Now this kind of a system is very reliable and it is very
economical because there is no operating cost here. There are no pumps and we are not
expending any energy and water flows only by gravity from the distribution reservoir to
the distribution area.

In combined system: In a combined system, the pump house which pumps water from the
treatment plant to an elevated reservoir which is at a slightly higher elevation. So there is
a pumping which is taking place from the treatment plant to the elevated reservoir and
from the elevated reservoir the water flows to the distribution area by gravity.
• In a pure pumping system we put a pumping plant and the treatment plant very
close to the source.
MATERIALS USED FOR CONSTRUCTION OF PIPES

• Pipes come in several types and sizes. They can be divided into three main
categories: Metallic Pipes, Cement Pipes And Plastic Pipes.

• Metallic pipes - steel pipes, Galvanized iron pipes and Cast iron pipes.

• Cement pipes - concrete cement pipes and Asbestos cement pipes.

• Plastic pipes - Plasticised Polyvinyl Chloride (Pvc) pipes.

Galvanized iron pipes: This type of pipe is used for water supply work
inside the building. These pipes are wrought steel pipes provided with zinc
coating.

Application Areas:

• Water & Sewerage.

• Fire Fighting Installations.

• Plumbing Systems
Galvanized iron pipes
Advantages Disadvantages
• Low installation and
• Heavy to handle.
maintenance cost.
• Long life. • Develops blockages.
• Toughness.
• Difficult to repair
• Anti-rust pipes.
• Useful for large construction
projects-durable and large
diameter
pvc/plastic/polythene pipes :
• These pipes are being used increasingly these days for supply of cold water in
external and internal plumbing work.

• There are 3 common types of plastic pipes are available in market, as given below.

• Unplasticized pvc (upvc) or rigid pipes - for use with cold water.

• Plasticized pvc pipes - which are plasticized with addition of rubber. It has lower
strength and lower working temperature than upvc pipes.

• Chlorinated pvc (cpvc) pipes - which can withstand higher temperatures. (used to
carry hot water).
• Rigid pvc pipes are used for distribution of water with temperature
below 450 C.
pvc/plastic/polythene pipes
Advantages Disadvantages
• Durable. • Heat Constraints.

• Corrosion Resistant. • Cost.

• Insulation. • Weight.
Steel Pipes:
• Steel pipes are comparatively expensive.

• But they are the strongest and most durable of all water supply pipes.

• They can withstand high water pressure, come in convenient (longer)

lengths than most other pipes.

• Thus incur lower installation/transportation costs.

Steel Pipes: Advantages
• Steel is strong and will resist damaging factors that can ruin other
pipes, such as tree roots and extreme weather conditions.

• Unlike plastic pipes, steel pipes are 100 percent recyclable. when the
pipes are no longer needed, they can be melted down and turned back
into other useable metal pieces in other industries.
Steel Pipes: Disadvantages
• It is often more expensive.

• It is very difficult to fabricate and since it is not that much malleable

as compared to other metals therefore it is difficult in case of repair.

• Thermal conductivity is very poor.

Uses of steel pipes: Water Mains, Sewerage Systems, Industrial

Water Lines, Deep Tube-wells, Pipe Lines For Natural Gas
Concrete Pipe:
• Steel reinforced concrete pipe (SRCP) has a product life of 100 years.

• It is the low risk choice for specifies with a long history of reliability.

• No limits to weather exposure prior to installation.

• Increasing strength over time.

• It is easy to join and install.

Applications:
• Transverse culverts
• Stormwater drainage
• Irrigation
• Tunnelling
 Concrete Pipe: Advantages
• Suitable for conveying all types of water.

• Easy to install and with flexible joints.

• Can withstand backfill pressure, as well as vehicle traffic loads taking place
above it.

• Because of the smooth inner surface, there are small friction losses;

• They are available in different diameters ranging (300-1,500 mm for the first
type of pipe; 1,000-4,000 mm for the second type).

• They are water tight and durable, even with cracks in the inner and outer
coating layers
 Concrete Pipe: Disadvantages
• It is necessary to conduct detailed studies regarding the pipe fittings, based on
the specific project requirements.

• They are heavy, with this feature being reflected in their transportation and
installation costs.

• It is difficult to re-establish the inner and outer pipe coating if it is damaged

during repair works.

• They require special care in its manufacturing, transportation and installation.

• They may require grounding measures in some cases.

Asbestos-cement Pipes:
• These pipes have been in use throughout the world since 1913.

• They are made of a mixture of 82-90% cement and 10-18% asbestos fibers.

• They are available in diameters ranging between 60-2,000 mm, and can
withstand pressures.

• The use of asbestos pipes to convey potable water over the last two decades,
due to increasing concern with their health hazards.

• However, they are still used to convey irrigation and sanitary drainage water.
Asbestos-cement Pipes: Advantages
• They are resistant to wear and corrosion, thereby being useful in situations
involving corrosive water or soil.

• They have smooth internal surfaces, resulting in low friction losses.

• The major raw material (cement) required for their manufacture is usually
available locally.
 Asbestos-cement Pipes: Disadvantages
• The asbestos material used in manufacturing the pipes represent a
carcinogenic health.

• The pipes have a low resistance to vibrations from vehicular traffic passing
over them.
Sanitary Provisions & Accessories of Sanitary

Ventilation System

Water Closets

Flushing Cistern

Bath Tubs

Lavatory Basins/Sinks

Traps
Lavatory Basin
Water Closet Flushing Cistern
 Plumbing Methods / System of Plumbing
4 systems of plumbing for building drainage.

1. One – pipe system of plumbing

2. Single stack system of plumbing

3. Single stack partially ventilated system

4. Two pipe system of plumbing

Waste pipe: pipe for draining away the wastes of a building other than those
from water closets.

Soil pipe: pipe that conveys sewage or waste water from a toilet/ water closets.

Stacks: All plumbing waste fixtures use traps to prevent sewer gases from
leaking into the house. Through traps, all fixtures are connected to waste lines,
which in turn take the waste to a soil stack.
Traps: Trap retains a small amount of water after the fixture's use. This water
in the trap creates a seal that prevents sewer gas from passing from the drain
pipes back into the occupied space of the building.
Vent pipe:
Gully trap: is a basin in the ground which receives wastewater from
your kitchen, bathroom and laundry before it is emptied into the sewer.
The basin has a water seal to prevent foul odours of the sewer reaching
the surface.
One – pipe system of plumbing:
Adopted in multi storied building.

This system carries both waste from soil pipe and waste pipe in a single pipe.

Stacked vertically in all floors one above the other.

Provision for ventilation pipe.

No gully traps.

Better Appearance
Advantages:

Largely replaced two pipe system in most developed countries.

Constant flow – no blockage.

Highly economical

Quick to construct

Disadvantages:

Danger of back flow of sewage in waste fittings.

Single stack system of plumbing:

Similar to One – pipe system of plumbing

No ventilation of traps is provided.

Poorly ventilated system

Simple and easy to construct.

Single stack partially ventilated system:
It is a combination of one pipe and single stack system.

A single pipe for collecting the discharges from all water closets, baths, sinks
and basins.

Only ventilation pipe is provided for the water closets.

Traps of bath, wash basins and kitchen are not joined with vent pipe.

Economical system.

Simple arrangement of pipe.

Two pipe system of plumbing:
In this separate soil and waste pipes are provided.

Soil pipes – directly – drains/manhole

Waste pipes – connected - gully traps

Ventilation system is provided

No blockage of pipes

Solid waste collection - gully traps – periodically maintenance

Enable waste water – gardening

Problems Associated with Plumbing
• Refer Journal
Activity flow chart for Plumbing work:
Water Harvesting:
• Because of Mindless extraction and over exploitation of very small
quantity of water, has caused rapid depletion and deterioration in its
quantity and quality.
• Methods and techniques for ground water recharge.
Urban Areas Rural Areas
Roof Top Rain Water / run Rain Water Harvesting through
off harvesting through •Gully Plug
•Recharge Pit •Contour Bund
•Recharge Trench •Gabion Structure
•Tubewell •Percolation tank
•Recharge Well •Check Dam/ Cement Plug/ Nala Bund
•Recharge shaft
•Dugwell Recharge
•Ground Water Dams/Subsurface Dyke
Gully Plug:
• Gully plugs are built using local stones, clay and bushes across small gullies and
streams running down the hill slopes carrying drainage to tiny catchments during
rainy season.
• Gully Plugs help in conservation of soil and moisture.
• The sites for gully plugs may be chosen whenever there is a local break in slope to
permit accumulation of adequate water behind the bunds.
 Contour Bund:
• Contour bunds are effective methods to conserve soil moisture in watershed for long duration.
• These are suitable in low rain fall areas where monsoon run off can be impounded by constructing
bunds on the sloping ground all along the contour of equal elevation.
• Flowing water is intercepted before it attains the erosive velocity by keeping suitable spacing
between bunds.
• Spacing between two contour bunds depends on the slope, the area and the permeability of the
soil. Lesser the permeability of soil, the close should be spacing of bunds.
• Contour bunding is suitable on lands with moderate slopes without involving terracing.
Gabion Structures:
• This is a kind of check dam commonly constructed
across small streams to conserve stream flows with
practically no submergence beyond stream course.
• A small bund across the stream is made by putting
locally available boulders in a mesh of steel wires and
anchored to the stream banks.
• The height of such structures is around 0.5 m and is
normally used in the streams with width of less than 10
m.
• The excess water over flows this structure storing some
water to serve as source of recharge. The silt content of
stream water in due course is deposited in the void
spaces of the boulders. With the growth of vegetation,
the bund becomes quite impermeable and helps in
retaining surface water run off for sufficient time after
rains to recharge the ground water body.
 Percolation Tank:
• Percolation tank is an artificially created surface water body,
submerging in its reservoir a highly permeable land, so that
surface runoff is made to percolate and recharge the ground water
storage.
• The recharge area down stream should have sufficient number of
wells and cultivable land to benefit from the augmented ground
water.
• The size of percolation tank should be governed by percolation
capacity of strata in the tank bed.
• The percolation tanks are mostly earthen dams with masonry
structure only for spillway.
• The purpose of the percolation tanks is to recharge the ground
water storage and hence seepage below the seat of the bed is
permissible.
Check Dams:
• Check dams are constructed across small streams having gentle
slope. The site selected should have sufficient thickness of
permeable bed or weathered formation to facilitate recharge of
stored water within short span of time.
• The water stored in these structures is mostly confined to stream
course and the height is normally less than 2 m and excess water is
allowed to flow over the wall. In order to avoid scouring from
excess run off, water cushions are provided at downstream side.
• To harness the maximum run off in the stream, series of such check
dams can be constructed to have recharge on regional scale.
• Clay filled cement bags arranged as a wall are also being
successfully used as a barrier across small nalas. At places, shallow
trench is excavated across the nala and asbestos sheets are put on
two sides. The space between the rows of asbestos sheets across the
nala is backfilled with clay. Thus a low cost check dam is created.
On the upstream side clay filled cement bags can be stacked in a
slope to provide stability to the structure.
Recharge Shaft:
• This is the most efficient and cost effective technique to recharge
unconfined aquifer overlain by poorly permeable strata.
• Recharge shaft may be dug manually if the strata is of non-caving
nature. The diameter of shaft is normally more than 2 m.
• The shaft should end in more permeable strata below the top
impermeable strata. It may not touch water table.
• The unlined shaft should be backfilled, initially with boulders/ cobbles
followed by gravel and coarse sand.
• These recharge structures are very useful for village ponds where
shallow clay layer impedes the infiltration of water to the aquifer.
Continuation..,
• It is seen that in rainy season village tanks are fully filled up
but water from these tanks does not percolate down due to
siltation and tubewell and dugwells located nearby remains
dried up. The water from village tanks get evaporated and is
not available for the beneficial use.
• By constructing recharge shaft in tanks, surplus water can be
recharged to ground water. Recharge shafts of 0.5 to 3 m.
diameter and 10 to 15 m. deep are constructed depending upon
availability of quantum of water. The top of shaft is kept
above the tank bed level preferably at half of full supply level.
These are back filled with boulders, gravels and coarse sand.
• In upper portion of 1 or 2 m depth, the brick masonry work is
carried out for the stability of the structure.
• Through this technique all the accumulated water in village
tank above 50% full supply level would be recharged to
ground water. Sufficient water will continue to remain in tank
for domestic use after recharge.
Dug Well:
• Existing and abandoned dug wells may be utilized as
recharge structure after cleaning and desilting the
same.
• The recharge water is guided through a pipe from
desilting chamber to the bottom of well or below the
water level to avoid scouring of bottom and
entrapment of air bubbles in the aquifer.
• Recharge water should be silt free and for removing
the silt contents, the runoff water should pass either
through a desilting chamber or filter chamber.
• Periodic chlorination should be done for controlling
the bacteriological contaminations.
 Ground Water Dams or Subsurface dykes:
• Sub surface dyke or under-ground dam is a subsurface barrier across
stream which retards the base flow and stores water upstream below
ground surface. By doing so, the water levels in upstream part of
ground water dam rises saturating otherwise dry part of aquifer.
• The site where sub-surface dyke is proposed should have shallow
impervious layer with wide valley and narrow out let.
• After selection of suitable site, a trench of 1-2 m wide is dug across the
breadth of stream down to impermeable bed. The trench may be filled
with clay or brick/ concrete wall upto 0.5m. below the ground level.
• Since the water is stored within the aquifer, submergence of land can
be avoided and land above the reservoir can be utilized even after the
construction of the dam. No evaporation loss from the reservoir and no
siltation in the reservoir takes place. The potential disaster like collapse
of the dams can also be avoided.
Ground water Recharge In Urban Area:
Recharge Pit Method:
• Recharge Pit Method is most suitable for such alluvial areas (plains) where
permeable strata are not below than 2 to 2.5 meter deeper from the ground
surface.
• This technique is generally considered suitable for the roof having 100
SQM areas and it is constructed to recharge shallow aquifers.
• Recharge pit may be of any size and shape and this is constructed generally
with the width of 1 – 2 M, 1.5 to 2 M deeper or according to the availability
of permeable strata.
• This pit is filled with layers in graded form with the boulders of 5-20mm,
gravels of 5– 10mm, thick sand/Morang (1.5 to 2mm).
Recharge Trench Method:
• Recharge trench is also a simple method like recharge pit.
• Difference is only of shape and size. Recharge trench is suitable for
the buildings having roof size from 200-300 SQM. This method will
also suit those areas where permeable strata are available on shallow
depth.
• Recharge trench is filled with boulder (5 to 20 C.M.), Gravel (5-
10M.M.) and thick sand/Morang (1.5 – 2 M.M.) in sequence.
Recharge Well method:
• In areas where top layer clay is impervious and its thickness is
comparatively more, aquifer is 25 to 30M deeper or more, adoption of
“Recharge Well Method” will be most suitable.
• In the multi-storied buildings (roof area is 400 – 1000 SQM or more), this
technique is generally suites better especially where the place is limited and
water level is deeper. This method can also be used for the rooves having
lesser area like 100, 200, 300 SQM.
• With the help of this technique, stressed aquifer can be recharged directly.
By this method, rain water received from the rooves under recharge system,
will reach at filter chamber first through piped conveyance network. The
water will be stained here and will reach in the storage tank made from
concrete. Rain water will enter through slotted pipe/strainer in the well,
constructed within the chamber and recharge the aquifer directly.
Recharge through Dry Open Well:
• If the area of roof is 300 SQM and general rainfall is 700MM to
900MM, in this case rain water collected from rooves can be easily
recharged through dry and open well.
• First of all, the dry well should be cleaned and boulders, gravel and
Morang layers should be filled in as filter up to 2- 3 meter thickness.
• Rain water received from the rooves should be flown through desilting
chamber so that silt etc. can be prevented to reach in the well
Water Distribution in High Rise Buildings:
• With the increase in density of population, there is an exponential
growth in vertical development calling as high rise structures.
• It will be a huge challenge when it comes to design an efficient water
distribution systems in these high rise structures.
Water Distribution in General:
Use of overhead tanks in high rise building:
• The use of overhead tanks to ensure adequate water pressure in
buildings, and especially tall buildings, is very common.
• The alternative to overhead tanks is the use of pressurized systems,
where several booster pumps provide the necessary pressure.
System Elements and Layout:
• The booster system is based on several basic hydraulic elements that
can be combined in different ways.
• Below are the most important elements which describes about
functionality and role in booster application.
1. Break Tanks or Underground tanks:
• Break tanks are implemented in boosting systems in order to supply
the system if the mains supply becomes insufficient during peak
demand, or if it is unstable.
2. Booster Pumps:

• People who live in multi-story buildings always need sufficient water

and does high quality pumps are crucial in booster system.
• Multi – stage pumps are used in multi storyed buildings.

3. Risers and Branches:

• Building supply system is normally divided into risers and branches
• In the risers, the geodetic height has been overcome, and the water is
distributed to the different floors.
• The branches distribute water to each tap point.
4. Pressure reduction valves (PRV)
• To equalize pressure on all floors, PRVs are often used in multi-story
buildings.
• The pressure is mechanically reduced directly by the spring, making it
possible to adjust the pressure precisely for each floor.
• The PRV can either be used individually with one on each floor or in a
branch of a riser supplying 2-3 floors.
• Booster systems may be designed in several different ways with the
elements described above.
• Which layout to choose depends on many factors and the specific task
in question, e.g. local legislation and traditions, flexibility
requirements or the possibility for future expansions etc.
Single Booster System:
• A single booster system is perhaps the simplest booster system
available.
• It relies on a single set of pumps supplying pressure boosting from the
basement to the point farthest away from the booster system.
Zone-divided booster systems:
• The building is divided into pressure zones of ten floors or less with a
booster supplying each zone from the basement through dedicated
risers.
Overhead tanks with terrace booster
system:
• Overhead tank systems use a transfer pump in
the basement to fill the overhead tank by a level
switch-operated control.
• The solution requires pressure reduction valves
on each floor if the building exceeds
approximately 15 stories, to avoid unwanted
high static pressure at the taps in the lower
floors.
• It also requires a terrace booster to provide the
top floors with the required pressure, as static
pressure there will be too low due to insufficient
geodetic height at the overhead tank.
Series Connected system with Intermediate break tanks:
• In this system, a building is divided into smaller and more manageable
pressure zones. Every zone is then served by its own booster set.
Series Connected system without Intermediate break tanks:
• It enables an effective usage of power as the water is only pumped to
the part of the zone where it is used and not past it.