The Brew Cabin

Hi tony just a quick query, at what point does surface water on block paving become classed as puddles and not suface water making it way to the drainage point? i have a job where the gradient is very slight but enough to move the water on but the water moves pretty slow and on the way probably gets to about 3mm deep while it raining heavy ,would this be classed as puddles and thus unexeptable. your thoughts are much appretiated.

I'm not sure if there is an official definition for block paving, but a Clerk of Works I used to harrass while working on sites with with my Dad when I was just a lad in the 1960s always used to say that if standing surface water covered a penny (and these were the old 1d pennies), then it was 'ponding' and would have to be relaid. I reckon that still holds good today, even with the decimal pennies, which are around 2mm thick.

Standards are slightly different for different materails. I know that machine laid bitmac has a pretty tight tolerance (3mm in 3m, IIRC) but tolerances for elemental pavings are not as 'tight' and 3-6mm in 3m would be more usual.

I still prefer the 'penny test' though. :)