PREFABRICATED UNIT BATHROOM SYSTEM

In any building projects, the toilets or bathrooms have been the most labour intensive operation in terms of quality finishes and accessories installation.

Good standards and high quality workmanship are expected in the construction of toilets and bathrooms to avoid maintenance and water-tightness problems.

Bathrooms built by conventional method are a constant headache to main contractors as the dirty wet work involves many sub-contractors working in the small space to meet the construction schedule.

The "unitised toilets and bathrooms" in the form of prefabricated/precast components or cells are being used increasingly in Korea, Japan and Europe since the 1960s. This system is clean and dry, takes a short time to install and only one supplier carries out the work.


Definition

What is a "Unitised Toilet and Bathroom"?

The unitised toilet and bathroom, or otherwise known as the prefabricated toilet and bathroom system utilised a dry construction method in which the components are produced in advance at a factory and, then assemble and erect at the construction site.


Types of Prefabricated Bathroom and Toilet System

The types of prefabricated bathroom and toilet available are:-
a. Concrete
b. Fibre Reinforced Plastic
c. A combination of steel wall panels and concrete floor panel
d. A combination of cement board wall panels and either concrete or fibre 
    reinforced plastic floor panel.

These bathrooms and toilets can come in the following forms:-
a. The unit with finished wall and floor is assembled at the factory before delivery 
    to the worksite.
b. The components of the unit are delivered as individual panels and, then 
    assemble and erect at the designated locations.

These units can come complete with accessories including sanitary, mechanical and electrical fittings.

Gaps are provided between the unitised bathroom/toilet and supporting structural slabs or walls easy installation, to conceal pipes and wires, and for maintenance purposes.

Floor Traps - the unitised bathroom/toilet can use either the conventional S-type or the new P-type.

However, the P-type floor trap is preferred. It is at floor level that makes maintenance easy. Being compact, pipes do not protrude into the ceiling of the unit below.


Benefits of Using Prefabricated Toilet and Bathroom System

The prefabricated bathroom and toilet system provides the following advantages:-

a. Save Time and Money
    - Building construction time is shortened as fabrication of the bathroom/toilet 
       can proceed in parallel with other worksite activities
    - Two or three persons to install one bathroom/toilet in two to three days
b. Reduces the Need for Skilled Labour
    - Do not require skilled workforce at site as wet work is reduced or eliminated
c. Allows Freedom in Planning
    - Design flexibility and convenient construction method
    - Wide selection of materials to suit individual choice and tast.
d. Maintains a Consistently High Quality
    - Fabrication at factory ensures uniform finish and better quality
    - One supplier is responsible for the entire system
e. Streamlined Material Deliveries
    - "Just-in-time" delivers of bathroom and toilet can be adopted.
f. Model Bathroom/ Toilet ready for Testing before Series Production
    - Inspection and approval of the prototype eliminates potential problems at 
       worksite.
g. Ready to Use Modules
    - Bathroom/toilets erected are ready for immediate use


Building Projects in Singapore Using Prefabricated Toilet and Bathroom System

1. HDB Project at Hougang Neighbourhood 1

    The Housing and Development Board in 1996 introduced a pilot project to install 
    two types of prefabricated bathroom system at the Hougang Housing Estate.

    The first type was the precast and pre-assembled toilets unit. The toilet 
    delivered to site as a complete unit with galvanised steel wall and a precast 
    concrete floor finished with floor and wall tiles. The toilet sat on in-situ floor 
    slab.

    The second type of toilet was imported from Japan. The unit consists of 
    fibreflass floor panel with tiles, laminated cement board wall panels with tiles 
    and steel sheet ceiling panel. These panels were delivered to site as individual 
    panels and assembled on location with fittings. The floor panel sat on in-situ 
    concrete slab.

    In 1998, HDB carried out a survey and 80% of the residents were satisfied with 
    the prefabricated toilets. Residents were pleased with the conceled piping and 
     wiring and aesthetics. Unfavourable comments were hollowness of the walls and 
    the size of the windows.

2. Private Residential Project

    Trellis Towers is the first private residential project to use the prefabricated 
    bathroom/toilet system. The panel walls were steel frames laid with marble or 
    tiles including sanitary, mechanical and electrical fittings. The finished panels 
    were hoisted into their final position to be mounted on block walls. The in-situ 
    concrete floor slab was cast with marble or tiles

3. Commercial Building Project

    The prefabricated toilets were used for the Transit Hotel at Changi International 
    Airport


Conclusion

Prefabricated toilet and bathroom system should be considered as the uniform finish and better quality of the toilets and bathrooms lead to a more buildable building.

In Japan, today an individual supplier supplies more than 200,000 units of prefabricated toilets per year for residential buildings and another 200,000 units for commercial buildings.