DEVELOPERS AND highway authorities are being swamped with so many different types of drainage product that they are specifying the wrong ones, manufacturers claimed this week.
Leading suppliers fear their reputations are suffering because incorrectly specified products are failing.
Products in question look like crates punctured with a grid pattern of holes.
Some have low load bearing capacity and are only for use in parks and pedestrian areas as they are too weak to support road vehicles.
More robust versions are available for car parks and road drainage.
Wavin Plastics makes both types. But Wavin Plastics marketing manager Julie Fleming said some systems with low load-bearing capacity had lapsed because they had been used incorrectly in areas like car parks.
'Because there are so many systems with varying strengths, the market doesn't necessarily understand the implications of these strengths, ' she said.
'Many think they are all the same and any can be used in any application.' Hydro proposals manager Alex Stephenson said some failures had 'scared off' buyers.
'We've been trying to get the emphasis on that to say there are a lot of systems available and you need to look at strength issues, ' he added.
'There is a market for the weaker systems but they should only be used in the right place.' Wavin is working with research body CIRIA to develop better specifying criteria.