Plastic drains - Exposed

[AndiForest]

I posted some pics in a previous post showing where plastic drains were very close to the existing driveway. Having excavated for block paving to provide the depth for sub base etc., a few feet of the drains are almost completly exposed supported by pee shingle. Two questions:
1 - Is it ok to drop type 1 sub base over exposed drains and compact or is it advisable to put concrete haunches around the pipe first.
2- will the shingle provide a sound enough foundation level for the sub base?

Cheers in anticipation of advice.

Andi

[andpartington]

email me a pick of the pipes in question and i will host for you andpartington@googlemail.com

how much room is there between the top of the pipe and the top of the sub base




andy

[matt h]

a lot depends on yr finish level... 150mm below dpc. you can cast plastic in concrete but it is your fall that is important,get some oe in the know to survey yr site and advise. a picture paints a thousand words

[andpartington]

andy

[Tony McC]

If there will be vehicles in this area, I'd haunch the pipes. If it's pedestrians only, I'd cushion them with grit sand beffore placing any Type 1 material near them.

[AndiForest]

Tony

Many thanks for your advice. It is really appreciated as some of us amateurs quickly lose heart when these problems are exposed.