Page 1 of 1
Posted: Fri May 24, 2019 10:03 pm
by KAMIKAZEE DIY
Doing some research and read paving with a water absorption rate above 1.7% will discolour easily.
Would paving with water absorption rate of 1.7% increase or decrease the chance of mortar pointing stains occuring?
Posted: Thu May 30, 2019 9:50 am
by Tony McC
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!