Sanitary fittings

It is observed that sanitary fittings are allied items and are often incorrectly planned, selected and fixed. As the use of these items has not become common, it is essential that all technical staff should be able to execute these items correctly. Some guidelines regarding them are as follows:

Metric dimensions corresponding to the various dimensions in feet and inches are given in brackets. They are not necessarily exact equivalents.

In the case of sizes of various fittings, they are in most cases as given in the relevant Indian Standard Specification. In the case of spacing etc., the exact metric equivalent is rounded off suitably for convenience in execution.

1. Wash Basins

1.1 Wash basins are made in different types and sizes, but most of them fall under one of the following three types:

a. Flat Back Type
This type projects from the surface of a wall and is supported on cast-iron brackets embedded in the wall (Fig. 1A and 1B).

b. Angle Back Type
This type is fixed in a corner and supported from the walls.

c. Floor Supported Type
This may be supported by a pedestal near the outlet or a suitable frame near the edges.

The first is by far the most common type and is made in various sizes. The two most common ones are 24″ × 18″ (610 mm × 457 mm) and 22″ × 16″ (559 mm × 406 mm). The latter size is suitable in most cases. Sizes smaller than this, such as 18″ × 12″ (457 mm × 305 mm), are not recommended for normal use.

The basin should comply with the Indian Standard Specification for white glazed earthenware sanitary appliances (IS: 771-1958 / later revisions) and should be free from defects in glazing and form distortion.

The second type is also covered by the same ISS, which specifies sizes of 24″ × 18″ (610 mm × 457 mm) and 20″ × 16″ (508 mm × 406 mm). The third type is more or less similar to the first except for its method of support.

Wash basins are sold without supporting brackets, pillar taps (para 1.4), waste fittings (para 1.7) or traps, which are sold separately.

1.2 The basin should be fixed perfectly level, both parallel to the wall and at right angles to it, with the top of the rim normally at a height of 30″ to 32″ (760 to 810 mm) from the floor. In the case of schools or for children, the height may be suitably reduced.

When a number of basins are fixed side by side in a row (as in offices and other public buildings), the centre-to-centre distance should not be less than 28″ (710 mm). The distance between the side of a basin and an adjoining cross wall should not be less than 6″ (150 mm) (Fig. 1C).

1.3 Basins are available either with two tap holes or with one. If a basin with two tap holes is used and only one tap is fitted, the unused hole should be closed with a white glazed earthenware button or plug. The tap holes should be square.

1.4 Pillar Tap
Pillar taps fitted to wash basins should comply with IS: 1795 (Pillar taps). The size should be ½″ (15 mm) nominal and preferably chromium-plated. The capstan head should be correctly marked “C” (Cold) or “H” (Hot). It is not uncommon to find cold-water taps wrongly marked “H”.

The tap should project sufficiently into the basin to permit an ordinary lota or similar vessel to be filled from it. To prevent the tap from rotating in the basin, there should be a square under-flange or other suitable arrangement that fits the square hole.

1.5 When there is one pillar tap in the centre of the basin, the capstan head of the tap must be sufficiently above the top of the back, or the vertical axis of the tap sufficiently away from the back. If the former distance is A and the latter is B, then A + B should preferably be not less than 2½″ (65 mm) (Fig. 1B); otherwise there is a possibility of the fingers getting caught between the tap and the back while operating the tap.

1.6 The soap-holder recesses and the horizontal ledge at the back should have adequate slopes to drain into the basin. The recesses should preferably have integral diagonal ridges so that the bottom surface of the soap does not remain soaked in water.

1.7 Waste Fittings
The waste hole (outlet) of the basin may be either rebated or bevelled; the latter is preferable. The outlet should be fitted with a waste fitting or flanged outlet piece of 1¼″ (32 mm) internal diameter made of brass or other non-ferrous metal and plated (preferably chromium-plated). This fitting is available in two types — one with a square entry and the other with a bell-mouthed entry. The latter is preferable. Both the waste hole and the waste fitting should comply with the relevant Indian Standard.

In fixing the waste fitting, care should be taken to ensure that the top surface of the flange is nowhere even slightly above the inside surface of the basin; otherwise the projecting flange will prevent the basin from draining completely.

1.8 A shelf is often fixed to the wall above the wash basin. However, it is likely to hit the forehead as one bends over the basin. It is therefore better to provide a recess in the wall instead, or, if that is not practicable, to fix the shelf on one side of the basin. If space does not permit even this and a shelf has to be fixed over the basin, the shelf may preferably be quite narrow (say 4″ / 100 mm wide for a 22″ × 16″ basin) and fixed about 42″ to 45″ (1050 to 1150 mm) above the floor and not higher.

1.9 It is generally desirable to fix a mirror above a wash basin. The top of the mirror may be about 5′-9″ to 6′-0″ (1750 to 1800 mm) above the floor level, and the height of the mirror preferably not less than 18″ and better 21″ (450 to 550 mm).

1.10 An electric light should preferably be fixed over the mirror. Even if the basin is fixed inside a bathroom, it is more convenient to have the light over the mirror rather than in the centre of the bathroom. The light can be fixed either:

• (a) at a height of 7 ft (2.15 m) above the floor on a bracket projecting about a foot from the wall, or
• (b) at a height of 6 ft (1.80 m) above the floor just close to the wall.

Method (a) is the usual one, but unless the top of the mirror is appreciably higher than 6 ft above the floor, method (b) is preferable as it does not require one to stand fairly far away from the mirror for the light to illuminate the face directly.

2. Indian Pattern W.C.

2.1 Indian-pattern W.C. pans are made in two main types. The usual type has no squatting plate or foot-rest fixed to it. It should comply with IS: 771. It is made in different sizes, usually 18″, 20″, 23″, 25″ and 27″ (457 mm, 508 mm, 584 mm, 635 mm and 686 mm). The size is the length of the pan at the top measured from outside to outside, excluding the water inlet (which may be either at the front or at the back). Normally a 23″ or 25″ pan will be suitable if the back is sloping to make the pan anti-splash.

The width of the opening (parallel portion) varies from make to make, and some available in the market are too narrow. The Indian Standard specifies a width of 6¾″ (171 mm) for the 23″, 25″ and 27″ sizes, and this may be considered a suitable width.

2.2 The other type, known as Orissa or Oriya type, has a squatting plate or slab and foot-rests moulded integrally with the pan. It is also made in different sizes. This type of pan is much more sanitary and may be provided in better-type buildings where its higher cost can be met.

2.3 For either of the two types of pan, the trap is not a part of the pan and is sold separately. It should comply with IS: 771. In other respects the remarks in the relevant paragraphs apply.

2.4 When an Indian-type W.C. is to be provided in a building on a floor other than the ground floor, it is essential to ensure that the R.C.C. slab of the floor has been given a suitable slope from front to rear of the W.C. room, with the portion next to the wall kept about 21″ (535 mm) below the general floor level so that the top surface of the pan can be fixed at the floor level (Fig. 2A). The exact difference in level will depend upon the size and type of pan and trap used. If this is not done, the pan will have to be fixed above the floor in a masonry platform and provided with steps, which is a very inconvenient arrangement.

2.5 The usual type of pan should be so fixed that its top surface is level with the finished floor after tiling, etc., and not 2″ to 3″ (50 to 75 mm) below it with the flushing rim covered by the tiles (as is very often done). To achieve this, when the pan is fixed, the concrete is projected above the concrete surface to the extent of the thickness of the tiles and mortar layer below it. Before laying the pan, all paper, etc., sticking to it should be completely removed.

2.6 Once fixed, a pan should be protected during the construction period from mechanical damage, mortar droppings, choking of the trap, etc., by providing a suitable cover of wooden planking, etc., over it.

2.7 The floor should slope towards the pan from all directions so that all spilled water is drained into it. At the door sill, the flooring of the W.C. room should be about ½″ (12 mm) lower than the flooring outside.

2.8 The minimum size of a W.C. room is 4′ × 3′ (1.20 m × 0.90 m), but a larger size — say 4′6″ × 3′6″ (1.35 m × 1.05 m) or 5′ × 3′6″ (1.50 m × 1.05 m) — should normally be provided, particularly if the door opens inwards as usual.

3. Pedestal or Western-Type Water Closets

These are made in two types:

a. Wash-down type — This is the usual type. It should comply with IS: 771.

b. Siphonic type — This type is less noisy in action and is self-cleaning.

3.2 The trap is integral with the W.C. (unlike the Indian-type W.C. pan where it is a separate piece). It may be of ‘P’ type (soil pipe taken out through the wall) or ‘S’ type (soil pipe taken out through the floor). Normally the ‘P’ type is more suitable on floors other than the ground floor. On the outlet side of the trap there should be a branch connection for joining to the anti-siphonage pipe (unless the building is a ground-floor structure).

3.3 The pedestal should be free from distortion, the top sloping neither to the right nor to the left.

3.4 Seat and Cover
The seat and cover should be of a material that will not absorb moisture. The usual materials are wood, wood covered with plastic, or wholly plastic. Wooden seats should be made from well-seasoned hardwood and given either French polish or cellulose lacquer. It should be ensured that the under-side of the seat (which is often left untreated) is also polished or lacquered. If plastic seats are fitted, they should preferably be of a type that is flat on the under-side. Plastic seats are non-absorbent but, being brittle, are more liable to damage by rough usage than wooden seats. Rubber buffers (four in the case of wooden seats and three for plastic seats) should be provided on the under-side to avoid damage to the pedestal and to reduce noise. The seat and cover should comply with IS: 2548 (or the then-current equivalent).

3.5 The better way of fixing wooden seats and covers to the pedestal is to use pillar-seat hinges made of a non-corrodible metal. These hinges should have bolts not less than 5/16″ (8 mm) diameter, fixed to the pedestal with lead or rubber washers and self-locking nuts on the under-side. Every attempt should be made to use such hinges instead of the common type (a modified pattern of ordinary butt hinges) fitted to ready-made wooden seats, which is not substantial and has a comparatively short life. If the latter type has to be used, it should at least be fixed with plated brass screws and not ordinary iron screws. Plastic seats are usually provided with a hinging arrangement of their own which varies from make to make.

3.6 When a low-level flushing cistern is used, the pedestal should be fixed at such a distance from the wall or the cistern that when the seat and/or the cover are raised they rest against the front of the cistern in a stable position with no tendency to fall back upon the pedestal.

4. Urinals

4.1 As a rule, urinals are required only in public buildings and not in residential quarters other than hostels. The two main types in use are:

a. Basin type with lip and flushing rim, fixed to the wall. It should comply with IS: 771.

b. Stall type.

4.2 The stall type is more sanitary and should be preferred where its higher cost can be met. Both types are available either for fixing flat against a wall or in a corner.

4.3 The flooring and, in the case of basin type, the surrounding walls also should be covered with impervious materials.

4.4 When there is a row of urinals along a wall, the centre-to-centre spacing may be:

• Basin urinals — not less than 24″ (610 mm). The height of the lip of the front end may be 26″ (660 mm) above the floor level for adults.
• Stall urinals — according to the width of the stall, but usually about 24″ (610 mm).

4.5 Generally, automatic flushing cisterns are provided for urinals in public buildings. If manually operated cisterns are used, their capacity should be one gallon (approximately 5 litres).

5. Flushing Cisterns and Flush Pipes

5.1 Types and Capacity
Manually operated flushing cisterns may be:

• a. High-level — usually made of cast iron and operated by pulling a chain.
• b. Low-level — body of earthenware, enamelled pressed steel or cast iron, operated by rotating a lever through a small angle.

For Indian-pattern W.Cs., type (a) is used; for pedestal or Western-pattern W.Cs., either type may be used.

The cistern (whether high-level or low-level) with its accessories should be of mosquito-proof type and comply with the relevant Indian Standard for flushing cisterns (valveless siphonic type).

The Standard lays down capacities of 5, 10 or 15 litres (approximately 1, 2 or 3 gallons). The 5-litre size is meant for hand-flushed urinals. For W.Cs. the 15-litre (3-gallon) size should generally be used.

High-level cisterns are usually sold with ball valve and pulling chain, but flush pipes, overflow pipes, brass fittings at the inlet and outlet, and C.I. brackets, etc., are generally available separately.

5.2 Source of Supply
The cistern should preferably be supplied with water from an independent tank and not from a tank supplying water for other purposes (bathroom, kitchen, etc.). Some municipal building regulations make the provision of an independent tank compulsory.

5.3 Height above the Floor
It is generally suitable to fix a high-level cistern with its bottom about 6′–6″ (2.00 m) above the floor level. A low-level cistern may be fixed with its bottom about 10″ to 12″ (250 to 300 mm) above the top of the pedestal-type W.C.; lesser heights are sometimes provided.

5.4 For proper functioning, the cistern should be fixed perfectly level, both parallel to the wall and perpendicular to it. The ball valve should be so adjusted (by bending the lever arm) that the valve closes and cuts off the water supply when the water rises in the cistern up to the working level. This working level is generally permanently marked on the inside of the cistern about 2½″ (65 mm) or more below the rim of the cistern.

5.5 In high-level cisterns the operating lever either passes through one end of the cistern or through the cover, or has its fulcrum axle passing through a hole, half of which is in the rim of the body and half in the rim of the cover. In the latter case two holes are usually provided so that the axle can be fixed from either the front or the rear, according to whether the cistern is fixed on the right-hand or left-hand wall. The unused hole should be closed with the cast-iron plug provided for the purpose to prevent entry of mosquitoes.

5.6 Overflow
The overflow pipe should be of ¾″ (20 mm) internal diameter with a non-corrodible wire gauge fitted to it to prevent entry of mosquitoes. It should be possible to clean or replace the gauge without difficulty. The pipe may be of metal or plastic and need project only about 2″ (50 mm) beyond the cistern. Long overflow pipes reaching almost down to the floor or passing outside through the wall are neither necessary nor desirable; they make replacement of the wire gauze more difficult and overflow may not be readily noticed.

5.7 Flush Pipe
The internal diameter of the flush pipe joining the cistern to the pan should be:

• 1¼″ (32 mm) in the case of high-level cisterns;
• 1½″ (40 mm) in the case of low-level cisterns.

The pipe may be made of lead, copper or copper alloy; stainless or welded steel tube not less than 1 mm thick and adequately protected inside and outside; or polyethylene. Smooth-bore cast iron can also be used for low-level cisterns. Flush pipes made from G.I. sheeting rolled into a tube with a longitudinal soldered joint are not permissible.

6. Sinks for Kitchens

6.1 These are made in various sizes. The relevant Indian Standard specifies the following three sizes:

• 24″ × 18″ × 6″
• 24″ × 18″ × 10″
• 30″ × 18″ × 10″

The top of the sink is normally fixed about 35″ to 36″ (890 to 915 mm) above the floor level.

7. Drinking Fountains

7.1 These should comply with the Indian Standard Specification for drinking fountains. Drinking fountains for adults should be fixed so that the top is 3′-0″ (900 mm) above floor level. In schools they should be fixed at a lower height to suit children. If there are two or more fountains they should be fixed at different heights to enable children of different ages to use the one most suitable to each.

8. Bath Rooms

8.1 Size
The minimum floor area of an enclosed bath recommended in the Indian Standard Code of Building Bye-laws is as follows:

• Single- and double-room tenements — 16 sq ft (1.5 m²)
• Other buildings:
  • Independent bathroom — 5′ × 4′ (1.50 m × 1.20 m) or 20 sq ft (1.85 m²)
  • Combined bath and W.C. — 30 sq ft (2.80 m²)

8.2 The floor level inside the bathroom should be ½″ to 1″ (12 to 25 mm) below the level of the floor in the adjoining room. The floor should be given adequate slope from all points towards the outlet. It is generally convenient to locate the outlet near a corner; in this case the slope will have to be given in a diagonal direction from the opposite corner towards the outlet.

8.3 The flooring and the dado to a height of three to four feet (900 to 1200 mm) should have an impervious surface. In better-class buildings it is usual to provide white glazed or concrete tiles. In such cases it is very desirable that all angles and corners are well rounded by special curved pieces of tiles. Such curved fittings are often omitted nowadays, which is unfortunate because a tiled bathroom lacks good finish without them. These fittings are of six types and should be invariably specified in tenders. In the case of concrete tiles they are not always readily available; in that case terrazzo work may be done in angles and corners if such fittings cannot be obtained.

8.4 Taps

Water taps should not be fixed above or very near the outlet; otherwise the waste water will touch the outside of the vessel being filled while flowing to the outlet and make it insanitary.

The tap should project not less than 7½″ to 9″ (190 to 230 mm) from the wall to enable wide vessels with narrow mouths to be filled. A longer projection of say 12″ (300 mm) enables a person to sit below the tap while bathing, but is apt to be an obstruction, especially in a small bathroom.

The height of a tap above the floor may be 24″ (600 mm) minimum. If the available water pressure is adequate it may be more — say 30″ (760 mm) or about 42″ (1070 mm) — a height which enables a person to sit below the tap (if there is no shower provided).

8.5 Shower Bath

A 4″ (100 mm) size rose is ample. A convenient height for an overhead shower is 6 ft (1.80 m) from the bottom of the rose to the floor.

Shower roses are sometimes fitted with the rose fixed at a small angle to the vertical instead of being horizontal. Such showers work satisfactorily only if there is enough water pressure to project the jets of water sufficiently forward. This difficulty is avoided by fixing the shower overhead and horizontal.

9. Ventilation & Light in W.C. Rooms & Bathrooms

9.1 Every W.C. room (and wherever possible a bathroom also) should have at least one of its walls an exterior wall facing an open area or an air shaft.

9.2 To provide natural light and ventilation there should normally be a window or ventilator in this exterior wall having an area of not less than 10 % of the floor area. The sill of the window or ventilator may be at any convenient height; a height of about 4′-9″ (1.45 m) will be found suitable in many cases.

9.3 In low-cost buildings R.C.C. jallis will serve the purpose in most cases. In better-type buildings either glazed windows (preferably centre-hung, i.e. rotating about a horizontal axis at mid-height) or glass louvers may be provided.

9.4 Glass Louvers
In many cases these do not appear to be properly proportioned. The most suitable material is perhaps ¾″ thick ribbed glass, but as such glass is not readily available, sheet glass approximately 7/32″ (5–6 mm) thick (44 oz per sq ft) should be used. Such glass is generally available clear (unobscured), so it should be ground on one face. The width of each louver should be 4″ (100 mm) and the long edges should be rounded by grinding so that the sharp edges do not cut the fingers while fixing or cleaning. The louvers should be fixed at an angle of 60° to the horizontal with the ground face on the underside. The optimum vertical distance between two adjoining louvers may be taken as 2¾″ (70 mm), but this distance may be varied between 2½″ and 3″ (65–75 mm) if required to suit the height of the opening. To prevent rain water from entering below the lowest louver, its lowest corner is taken about ⅛″ (3 mm) below the upper surface of the frame at the bottom and the portion of the frame outside the louver is given a slight slope. Similarly the topmost louver should project above the lower surface of the frame at the top.

The size of the frame will depend on the dimensions of the opening but should not be less than 3½″ × 2½″ (90 mm × 65 mm). It is desirable to restrict the length of individual louvers to about 24″ (600 mm) to minimise breakage. Therefore, if the width of the opening is large, it should be divided into two or more parts by mullions so that the length of the louvers is not excessive.

10. General

10.1 The position of all pipes and fittings should be decided and all details settled before the construction of the building has started. Such finalisation of details beforehand will reduce the delays which inevitably occur when works are hastily started without adequate planning.

10.2 By careful planning, the duplication of pipes (both for water and for waste) sometimes seen can be eliminated and their lengths reduced to the minimum.

10.3 Whenever possible, water pipes and soil pipes should be fixed in the walls while the walls are being constructed and not by cutting holes in completed walls. In any case, no plastering, white-washing or other finishing should be done unless all pipes and wooden plugs, etc., have been fixed in the wall.

10.4 All pipes and fittings should be readily accessible for repairs.

10.5 The type, size, capacity or other dimensions of each sanitary fitting should be clearly mentioned in both the estimate and the tender. The description of the item should also clearly state what necessary fittings are included in the item.

10.6 It would be a very good idea if a sample of approved quality and type of each kind of fitting is displayed in the Executive Engineer’s office for the guidance of the tenderers.