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CHAPTER 13: SERVICES

CHAPTER 13: SERVICES. INTRODUCTION. Building services have become a major item in modern buildings, and are costly to maintain and operate.

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CHAPTER 13: SERVICES

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  1. CHAPTER 13: SERVICES

  2. INTRODUCTION • Building services have become a major item in modern buildings, and are costly to maintain and operate. • Any specialist employed are well aware of their responsibilities and that they must submit a true report – must include an approximate estimate for any remedial work required to the installation.

  3. COLD WATER SUPPLY Types of Pipework • Any pipe below ground should be at least 900 mm underground in order to be clear of frost action. • A stop valve is situated in a brick or concrete pit just outside the boundary of the premises and is the property of the water authority. The valve is used to cut off the main supply when required. • Lead was usually specified for underground pipes in old buildings, but deteriorates with age and is now prohibited. • Copper is still used today – more durable – but can be attacked when the trench is being back-filled with rubble and will often need to be protected with bitumen-impregnated tapes and wrappings. • Polybutylene and unplasticised PVC – more economic, do not corrode although they can be damaged by careless handling. • Corrosiveness of soil: moist acid clay, wet acid peat are corrosive to metals. If chlorides or nitrates- lead to corrosion.

  4. Drain-off Stop valve Lead pipework Copper pipework Polybutylene and unplasticised PVC

  5. COLD WATER SUPPLY Types of pipework: The distribution of cold water through a building so that draw-off points can be adequately serve depends on the requirements of the local water authority and the available pressure on the mains.

  6. COLD WATER SUPPLY Guide to checking cold water installations: • At the point of entry into the building the rising main should be provided a drain-off tap and stop valve. • The drain-off tap – emptying the main pipe beyond where the water is shut-off by the stop valve. • The stop valve – will be found in a pit externally adjacent to the point of entry. • The internal cold supply should be fixed on internal partitions or walls, rather than on the inside of the colder external wall. If the pipes must be fixed in positions subject to frost they should be suitably protected. • No water for consumption should be taken from a storage tank. At least one branch should be taken from the rising main to serve a convenient water draw –off point which invariably supplies a sink unit. • Pipe runs feeding the various sanitary fittings should be designed that the whole system can be drained of water if necessary to enable repairs to be executed conveniently. • Trace the pipe through the building and where possible check joints, taps, valves and drain for pinhole leaks.

  7. COLD WATER SUPPLY Guide to checking cold water installations: • The installation should be planned to provide adequate protection to safe guard the pipes from damage by impact, expansion, contraction or corrosive action. In such cases, the pipes should be inserted in a metal sleeve to protect them against damage so that no joint is included in the encased section. • Horizontal pipe runs in timber floors, internal angles between wall and ceiling should be secured with suitable fixing devices. • Water hammer in cold supply systems is produced by a concussive effect caused by the quick shutting of a tap or ball valve transmitting a shock through the wall of the pipe. • The pipework should be carefully examined, particularly when a copper pipe is connected to a galvanised steel tank – electrolytic action between copper and zinc coating cause the zinc to deteriorate and ultimately perforate the steel tank.

  8. HOT WATER AND HEATING INSTALLATIONS Direct Heating Systems • The principal components: boiler; flow and return pipes; hot water storage cylinder; cold water supply pipe; expansion pipe; and draw-offs. • Furring of pipes in this type of system is common in ‘hard water’ areas.

  9. HOT WATER AND HEATING INSTALLATIONS Indirect Heating Systems • The water used indirectly by hot water in a calorifier placed in the hot water vessel. • In this system the hot water to the fittings does not pass through the boiler. Two separate cisterns are necessary. One is the feed and expansion cistern and the other is the cold water storage cistern for the building. Both act as expansion cisterns. • Advantages: only one boiler is necessary for both installations and after the initial deposit has taken place in the boiler the water constantly recirculates between boiler and calorifier • Both direct and indirect systems can be heated by a free-standing sow-burning solid fuel boiler.

  10. HOT WATER AND HEATING INSTALLATIONS Indirect Heating Systems

  11. HOT WATER AND HEATING INSTALLATIONS Oil-fired boilers • Always require a suitable flue. • Require the oil to be stored in a suitable fuel tank on the premises • Stringent regarding safety and the position of the oil storage tank in relation to the remainder of the premises is important. • Oil-fired installations can be a problem when it comes to testing the safety measures, such as valves controlled by fusible links to check the flow of oil to the boiler.

  12. HOT WATER AND HEATING INSTALLATIONS Gas-fired boilers • Can be free-standing or wall mounted connected to a conventional or balanced flue. • Some have permanent pilot light, others have automatic electric ignition to light the pilot which in turn lights the main burners when the boiler starts operating. • Gas room-sealed boilers in domestic property are usually installed in a kitchen area.

  13. HOT WATER AND HEATING INSTALLATIONS Wall mounted water heaters • Can be heated by gas or electricity. • Usually found above a sink unit in domestic properties and does not take up valuable floor space. • The water is heated at a single point and is supplied through a swivel arm outlet. • Receive the cold supply from a cold water storage tank which then supplies hot water to several fittings. Gas fires • Used for space heating and are frequently fixed to an open fireplace flue • Advisable to check some permanent ventilation has been provided for introducing air to all rooms where gas fires have been installed.

  14. Oil-fired boiler Wall mounted water heater Gas fires

  15. HOT WATER AND HEATING INSTALLATIONS Items to check • Older type properties may have one of the old type open-flued water heaters in the bathrooms or kitchen. If it not regularly serviced there is a possibility of danger. • The danger sign on water heaters are cracked and blocked flues, and orange or yellow flame. Gas fires also need regular service and cleaning: • The appliance should have a void behind it to accommodate any fall of soot (jelaga)or pargetting. • A closure plate should be provided to seal the gas fire to the catchment space, and must have a slot at the base to allow air to enter and to clean out the catchment space. • Check the appliance operates at the various settings • Ensure that the burners are clean and in sound working order.

  16. HOT WATER AND HEATING INSTALLATIONS Immersion heaters • Another method of water heating is by electric immersion heater fitted into a copper cylinder. • To prevent overheating, the immersion heater is thermostatically controlled • Cylinder capacities vary; standard size is 125L, but larger size are available if there Is sufficient space and heating capacity. • In modern building, the cylinders are coated with sprayed on foam insulation in lieu of jackets – very efficient and has a neat appearance. All pipes connected to the cylinder should also be insulated.

  17. HOT WATER AND HEATING INSTALLATIONS Storage heaters • Off-peak storage heaters consist of a metal cabinet containing blocks heated by electrical elements from the power supply. • The blocks absorb the heat during the hours of darkness, gradually emitting the heat throughout the following day. • To examine a storage heater the casing should be removed and the blocks checked for any signs of cracking which would impair the efficiency of the heater.

  18. HOT WATER AND HEATING INSTALLATIONS Boiler flues • Flues and chimney stacks serving gas and oil-fired boilers. • Adequate supply of air is needed in the room for the purpose of combustion. • In modern buildings, a gas-fired boiler operates in conjunction with a balanced flue. Balanced flues are used where there is no chimney at all or where the existing chimney is in the wrong position. • Very popular method now is the combination of solid fuel or gas boiler with an electric immersion heater fitted into the domestic hot water cylinder for summer or emergency use.

  19. CENTRAL HEATING Introduction • a system for heating the rooms of a building by means of radiators or air vents  connected by pipes or ducts to a central source of heat. • Many domestic properties now combine the hot water supply with a central heating system. • The heat-emitters can be convectors of different sorts and there are a number of ways to control the amount of heat for each room and the time the heat is switched on. • Only a complete test of the system will give a clear indication as to the efficiency of the boiler; whether the system is adequate for the heating of the rooms and the supply of hot water to the various draw-off points; and the system’s safety in operation.

  20. Central heating

  21. CENTRAL HEATING Common defects • Poor flow – due to air being drawn into the system through a vent pipe or an insufficient head of water. The defect can be remedied by raising the storage tank or inserting a larger supply pipe. • Check the system for leaks – trace the pipe runs through the building and where possible check joints, taps, valves and drain cocks for leaks. If severe leaks are found it is advisable to switch off the electricity supply at the main. • Check the controls – the system should have at least a two-period timer for intermittent heating and a thermostat. • Lack of hot water – caused by excessive length of primary flow and return pipes, air locks, poor quality fuel or by an inadequate sized boiler. • Pipe noises – knocking may occur in the primary flow and return pipes resulting from furring, corrosion or freezing of the water. In such cases the pipes may require descaling or renewing.

  22. CENTRAL HEATING Common Defects Oil-fired boilers: • Check that the oil tank is not empty and that the vent is clear. • Check that the oil filter is not blocked, so that no air lock in the oil supply pipe from tank to boiler. • Occasionally, the burner goes out, but there may be a reset button which has to be pressed. • Ensure that the electrical switches and fuses are in order. Gas boiler: • Ensure that all gas cocks and valves are in the open position, and that the pilot light is working. If the pilot light is unstable the cause could be a faulty thermocouple or too low gas pressure.

  23. CENTRAL HEATING Common Defects Solid fuel boilers: • This type of boiler may go out because there is not enough draught. The chimney should be checked to ensure that it is not blocked. • Conversely, a boiler may go out due to too much draught through the boiler when the dampers are closed. • Dampers should also be checked and the chimney examined for excessive draught. • Boiler will not burn well if incorrect fuel is used or the fuel is damp.

  24. CENTRAL HEATING Common Defects Water supply: • Check that the pump is switched on and running. When a pump is running correctly it produces a slight humming sound, which can be detected by holding a screwdriver or similar object against the pump with the handle close to the ear. • Poor circulation can be checked by feeling the connections on the flow and return to each radiator. • If the flow connection is hot and the return only slightly warm, this indicates a faulty pipe, wrong pipe sizes or a blocked pipe.

  25. SANITARY FITTINGS Materials • Advisable to consider the type and age of the fitting and not just its condition. • Sanitary fittings must be non-porous, durable and easily cleaned. • Vitreous china is probably the highest quality in sanitary ware, but fireclay, stainless steel and enamelled steel are also used. • Ceramic materials are sometimes difficult to control during manufacture – tends to warp (meleding) during drying and firing. Wash basins and shower trays • Available in fireclay and Perspex. Perspex trays are supported on a timber or steel angle cradle. If cracked, pitted, crazed or irretrievably stained, then the defects should be noted and replacement recommended. • Wash basins of stainless steel are usually found in commercial and industrial buildings – strongly made to resist damage by accident or misuse.

  26. SANITARY FITTINGS Baths • Usually of cast-iron with a porcelain enamelled finish, but expensive properties ceramic ware is sometimes found. • Reinforced Perspex baths are often used in more modern properties and are supported on a tubular steel frame with adjustable fixings. • Baths with timber panelled – the panels may affected by wet rot. • A lot of damage to baths is undoubtedly occasioned by impact damage which has often been ‘touched-up’ with paint – simply temporary, and the fault is discovered with use. • Bath panels sometimes have been tiled to match the wall tiling. Access can be difficult with panelled baths, and this is an area where defects are likely, ex: leaking traps or pipes which may have remained undetected for many years causing defects in the timber floor.

  27. SANITARY FITTINGS Bidets • Cast in vitreous china in various color and available with single or double taphole punching. They are fitted with flushing rim, overflow, ascending spray, pop-up waste or chain waste. • Most of the faults are the same as for wash basins. Sinks • Made of fireclay or stainless steel and are supported on the framework of a kitchen floor units. • Fireclay sinks are susceptible for damage as describe above for wash basins. • Stainless steel – moulded to form a combined sink and drainer unit, or twin washing-up bowls – hygienic surface and only requires general cleaning.

  28. SANITARY FITTINGS Taps • 3 basic types: • Bib taps : have horizontal inlet and free outlet and usually project above a sink. • Pillar tap : have vertical inlet and horizontal free outlet • In modern building, the baths and sinks are often fitted with a pillar mixer and swivel nozzle in the centre. • All types of washers wear with constant use and the sign of a worn washer is when the tap continues to run after being turned off. • If water discharges around the top of the tap spindle, this is due to faulty packing or a worn spindle.

  29. SANITARY FITTINGS Water closets and cisterns • Defects of this type harbour germs and are therefore insanitary. • Majority of pans are single trapped. The two-trap syphonic pans are usually found in larger buildings and are becoming increasingly common – more efficient and silent in action. • Carefully examine on a sign of ‘slow leak’. Damp floorboards are frequently the cause of wet rot around the base of a WC. • High level flushing cisterns made of cast iron with a bell-type action – deteriorated especially in older commercial and industrial buildings – source of noise and annoyance. • Recommend flush to modern low level suites – far less noise. • The cistern should be fitted with an overflow pipe to give warning of a fault and must discharge to the outside of the building. • The water level in the cistern should be approximately 25mm below the overflow pipe. The overflow pipe should be larger than inlet pipe, usually 19mm in diameter if a 13mm inlet pipe is fitted.

  30. SANITARY FITTINGS Water closets and cisterns • Flush pipes can be of copper, plastic or steel with a telescopic joint. • The following items should be checked: • The cistern brackets should be securely fixed to the wall. • The ball valves should be watertight and not punctured. • Inlet valves for faulty washers. • Flush pipe connections to the WC pan. The joint should be made with a rubber or plastic connector. • The lever action for loose or worn fittings.

  31. SANITARY FITTINGS Urinals • The weak point in the slab and stall type is the joint. Many of the older type urinals were installed with a cement joint, and if the jointing is porous or loose, absorption may be a high with a risk of seepage into the floor below. • Modern installations – the joints have been treated with a polysulphide rubber-based flexible sealer – high resistance to attack by acids and alkalis. • Many urinals are now made of stainless steel of one-piece construction eliminating risk of leaking joints. • All types of urinals should be fitted with a plastic or fireclay automatic cistern supplying 4.5 L of water per stall at maximum intervals of 25 minutes.

  32. SANITARY FITTINGS Urinals • The following points should be checked: • The floor adjacent to the channel should be impervious and fall towards the channel. • Channel outlets should be properly trapped and access provided by removable inlet gratings. • Urinals made of fireclay suffer the same faults as WC and basins when chips or cracks occur. • Urinal bowls need to be well secured to the wall with cast-iron hanger and bracket supports. All bowls must be fitted with trapped outlets and sealed joints. Ensure that outlets are not blocked.

  33. VENTILATION AND AIR CONDITIONING Natural ventilation • Requirement of Building Regulations: any habitable room shall have one or more ventilation openings (unless it is ventilated by mechanical means). • The total area of the open part of a window or hinged panel must be 1/20 of the floor area of the room served and open directly to the external air. • The opening portion must not be less than 1.75m above the floor. • In older building, habitable rooms have permanent ventilators in the form of terracotta air bricks or patent horizontal window ventilators fitted within the glazing rebates at the top of the metal or timber window. • Whichever system is found, only accidental damage can occur.

  34. VENTILATION AND AIR CONDITIONING Mechanical ventilation • Essential requirements for internal bathrooms, WC and kitchen where there is no natural ventilation at all. • The equipment consists of metal duct extractor fans allowing three complete changes of air per hour and must discharge directly into the external air. • The installers of this equipment will usually supply the occupiers with maintenance instructions that are simple to follow and easy to carry out. Air conditioning • Becoming important both for large manufacturing processes and for office buildings. • In a well designed system there are 5 important elements; temperature, humidity, cleanliness, distribution of air, noise control. • Temperature – provides comfortable condition for the people. • Whatever type of installation have been installed a good maintenance programme is vital and this include regular inspections

  35. ASSIGNMENT Question 1: The longevity of a natural slate roof depends on a number of factors, including the quality of the slates that were used, the skill in which they were cut and laid, and the exposure of the building to the elements. List the defects on the roof slate with the aid of picture/diagram as a prove of the defection that may occurred in the building. Question 2: The walls to the original part of the building measure up to 800mm in thickness and have a finishes. However, some common defects can be observed in plaster wall and ceiling part of the building. Briefly explain the common defects that may be counted for plaster wall and ceiling with the aid of picture/diagram. SUBMISSION DATE : 9 DECEMBER 2015 (WEDNESDAY) USE THE SAME COVER AS GIVEN BY PN FITRIAH.

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