Granite

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Maintenance and Cleaning

Granite and Other Igneous Rocks Maintenance Cleaning Method Cleaning Frequency
Natural granite and other igneous rocks specified and selected to BS 5390. Visual inspection every 5 years. If necessary cleaning, repointing and surface repairs in accordance with BS 6270: Part 1or CP 67 Part 1: 1997.

Thermographic test should be done in every 5 years to detect tile delaminations of tiled walls

 Generally, using high foaming jet is recommended with neutral cleaner. Avoid acidic, high alkaline and chlorinated products

Unpolished Granite*

  • Pressure washing (though bush hammer and flamed finished are more difficult to clean)
  • Use hydrofluoric acid together with orthophosphoric acid to remove stubborn soiling.
  • Alkaline cleaners followed by neutralization with a weak organic acid may also be successful.
  • Caustic soda cleaners should not be used.

Polished surfaces

  • Wash with clean water / pressure washing and a little mild liquid detergent and then clean off.
  • Chemical containing hydrofluoric acid and abrasive methods should not be used except in areas where repolishing is necessary. Alkaline agents followed by weak organic acid can be suitable.
  • Atmospheric soiling on polished granite may be removed using non-ionic soap in cold or hot water and associated with plastic pot scourers. Surfaces should then be thoroughly rinsed and wiped dry to prevent water spotting.
 Once a year
Uninsured, ie natural granite and other igneous rocks neither specified nor selected to BS 5390. None None None

Note:

Sealer/ Impregnator

For those used as external façade and interior, usually impregnation or sealing are done before installation to create a water or oil repellant membrane, yet allows the stone to breath and release moisture vapour. This can prevent staining caused by the growth of bacteria, mold and mildew, and also helps to prevent the adhesion and penetration of fluids and dirt.

For textured finishes, such as bush hammered and flame, the use of proprietary stone cleaner is also recommended, with the method of application follow closely with manufacturer instruction. This is normally designed with pH7 balanced, to be safely used without harming the stone’s natural crystalline structure.