Recent trials of older concrete block permeable paving projects, following long-term use, back up previous research, endorse current minimal maintenance recommendations and debunk misconceptions. Previous research has demonstrated that the infiltration rate will decrease in the jointing material, but then stabilise with age. Even after allowing for this, the long-term infiltration capability of permeable pavements will normally substantially exceed UK hydrological requirements.
Field tests were recently undertaken by an Interpave member on three projects installed 6-, 17- and 19-years ago respectively. All of the permeable paving sites tested, despite receiving no specific maintenance to improve permeability, still provide infiltration rates that would cope with any likely UK rainfall.
One of the trial projects is the subject of a video including an illuminating interview with the original designer about long-term performance and maintenance. It also highlights how concrete block permeable paving technology will play a key role in retaining and introducing trees, and other green infrastructure, into our towns and cities.