Case 2
- Introduction
- Causes of Defects
- Good Practices
- Standards
- Maintenance and Diagnostics
- Remedial
- Similar Cases
- References
Maintenance and Diagnostics
Maintenance
Wash and clean bathroom fittings regularly with mild detergents and remove any solid waste that may cause choking. Check pipe fittings regularly and, if necessary, have them repaired by a licensed plumber. Check for watertightness. Give careful consideration to possible openings and penetrations in fittings.
Remedy penetrations on pipe entries using local grouting via injection packers in accordance with BS EN 1504-5 or equivalent. For concealed pipes and sanitary fittings, or places where access for normal visual inspection is not possible, conduct an inspection using a fibrescope.
- Discharge pipe system should be kept clean regularly in order to maintain maximum efficiency.
- Care should be taken when using chemical descaling agents, which are often of a corrosive nature. Therefore, it is important to clearly identify the materials used in the system before using the chemicals.
- The following solutions are recommended for the different types of deposits:
| Type of scale | Cleaning method | Possible locations |
| Deposits due to misuse of the discharge system | Blockage due to large object or compacted masses such as toilet paper and sanitary towels can be loosened by rodding. | Discharge pipe |
| Lime scale | Periodic de-scaling using a suitable inhibited acid based cleaners (see Table 15 in BS 5572) | Discharge stack and pipes from urinals |
| Accumulation of greases and soap residuals | This can partially be removed by use of a plunger, but most effective way is by flushing the system with a strong solution of soda crystals dissolve in hot water (see Table 15 in BS 5572). | Discharge pipes from sinks or wash basins |
- An efficient inspection system should be adopted to ensure the conduct of regular checks such as visual inspections and tests to ascertain any other defects such as water leakages, wear and tear or negligence.
Diagnostics of Defect (see also NDT)
This instrument is useful when services are concealed. There have been many cases of collapse of large area of false ceiling, due to weight of accumulation of water or condensate. Regular inspection using a fibrescope/borescope could prevent such accidents.
A fibrescope or a flexible borescope is a flexible optical inspection device that consists of fibre optic bundles with an eyepiece at one end and a lens at the other.
A fibrescope usually comes in two bundles: (i) a fibre optic light bundle that is for illuminating the object to be investigated, and (ii) a fibre optic image bundle to relay the image to the eyepiece. It allows a direct visual inspection for an otherwise inaccessible part, as observations of remote, difficult-to-reach areas can be made through a video monitor with high-resolution images. The flexible fibres allow it to be manoevred in hard-to-reach or inaccessible areas.
It is often used to verify findings from other tests, such as infrared thermography or impact-echo testing.
Common applications include:
– Inspection of connecting condition behind the external cladding wall of a building.
– Inspection of defects on concrete surface(s) in a deep and narrow gap.
– Determination of corrosion condition of steel tendon(s) inside post-tensioning ducts of pre-stressed structural member(s).
– Investigation of service pipes, ducts and other inaccessible areas.
Microwave tomography is a technique to measure the moisture of various materials based on the relatively high dielectric constant of “water” in comparison to the dielectric properties of the material. An electrical field (microwave) is applied to the material, and the microwave induces oscillations of bipolar molecules (i.e., water). Water molecules will reflect and absorb an electrical field during oscillations. A higher electrical field reflected indicates higher water content.
The technique is non-destructive and applicable to wood, brickwork and concrete. The uniqueness of this technique is its ability to measure moisture content at various depths up to 110 mm, allowing the plotting of a 3-D contour of moisture content and facilitating the tracing of the water source.
Thermography can be used to identify the position of water leakages. The method is based on the characteristics of heat flow phenomenon, in a conductive medium of specific geometry, which is intended to model predetermined boundary conditions. Thermo tracer is an advanced equipment used in thermography technology.
Protimeter / Moisture Meter
Moisture meter is used to determine the presence of moisture [7]. Moisture readings can be taken within masonry walls, dry walls, insulation, concrete members, roofing, wood construction, and other building components.
