Case 4

Remedial (see also Remedial)

• Depending on the causes of staining, different measures can be taken to mitigate its influence. In most cases, only cleaning work is needed. However, if the staining is caused by the degradation of cladding materials and sealant, the replacement of defective element is needed.
• For slightly soiled surfaces, cleaning should be done with water and a dash of detergent. It should be completed by carefully rinsing with clear water and wiping with a soft and absorbent cloth.
• For moderately soiled surfaces where the soiling cannot be removed by the usual detergent, it is recommended that the product which is developed especially for this purpose be used. These products may contain detergent and very light abrasive material. The cleaning should be finished by rinsing with clear water and wiping with a soft cloth and absorbent cloth.
• For very dirty surfaces where the dirt is very stubborn, it may be necessary to apply the same means as mentioned in the preceding paragraph but with the use of synthetic pads of a type similar to Scotch Brite F Finishing. A final careful rinsing with clear water and wipe with a soft and absorbent cloth is necessary.
• It may be wise to remove and re-attach signage, letterings and other fixtures using the recommended method of attachment that allows a clearance between the fixture and the facade so that staining can be prevented.

Find the source of water ingress if any, stop further water ingress using methods such as sealing, injection, impregnation (see Remedial).

The affected areas should be washed cleaned with pressure jet and an abrasive cleaning agent. Washing should begin from the top. After the dust and dirt have been removed, the debonded tiles can be re-patched. Care must be taken in selecting the adhesive used so as to ensure effective adhesion to the concrete backing.

Removal of Efflorescence

-If efflorescence exists on an existing surface, the best method of cleaning or removing it, would be to use an acidic cleaner. These salts and minerals would readily dissolved in these acidic cleaning agents.
-Care should be taken when using these acidic agents which may be corrosive in nature.
-Occasionally, the cleaning and removal process can become more difficult if latex or chemical transmission occurs at the same time as the salts and minerals surfaced. These latex or comparable chemicals are often found in the more recent and advanced cementitious adhesives and grouts available and can form a protective layer which defends the efflorescence from direct contact with acidic cleaning products.
-To help solve this problem, select an acidic product that has cleaning agents in it (acid and cleaner in one single product). Another recommendation would be to use a high alkaline restoration cleaner to break down the latex protective coating, rinse well and then proceed with the acidic cleaning.

Repair: Application of Water Repeller

This type of solution act as a hydrophobic surface by penetrating into the pores of the bedding or screed layers and tightening the pores such that the water is not allowed to penetrate through.

It allows vapour to escape and prevent any development of hydraulic pressure caused by the retained moisture.

Repair: Application of Water Proofer (Silicate based)

This kind of solution reacts with the free lime in cementitious materials and seals the pores and cracks in the surface. In fact, as long as moisture and free alkali is present, the reaction will continue by sealing pores. This can also be referred to as “active” repair.

Repair: Application Water-based Clear Coating (with polymer particles)

In this treatment the floor is ponded with the solution and allow the super fine polymer particles to penetrate into the porous structure to form a permanent and continuous plug.