On Sat, 07 May 2011 03:41:56 +0100 H. Neary wrote :
It seems to me that none returns on gas and water supplies would be
an absolute must for any property.

How often does something like this happen? 100 people x 3 days x
£30/day compensation = £9000. What would be the cost of installing
non-return valves? 30m? homes x £50? = £1.5bn.

Water regulations are meant to prevent backflow, but that's because
contaminating the mains water supply could have far more serious
consequences.

--
Tony Bryer, Greentram: 'Software to build on' Melbourne, Australia
www.superbeam.co.uk www.eurobeam.co.uk www.greentram.com