Joined: July 2004
||Posted: 30 May 2019,09:50
Increase, usually, but don't regard water absorption values as being a definitive and unfailing guide to staining potential. Some stones/pavings with WA values >2% will, it is true, readily absorb stain-causing material, but some of them will also rapidly surrender such material when washed down with soap and water.
The problems really come about when you have a substrate that is absorbent and with a high volume of micro-interstices, combined with hydrophobic contaminants: that's the best recipe for a hard-to-shift stain!
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