sewer drains in a area that is known as crag. ie rocky

E

EBMITIE

Guest
Is there anyway I can have a test done to establish if it is possible to dig deeper and better drains for sewers in an area where it is known to be rocky? House already built about 28 years ago.

Are these rock breakers capable of getting through the toughest crag?

And is there any minimum depth for drains?

ebmitie
 
Are you sure you want deeper drains? What do you mean by better? Is what the pipes are going into, low enough to allow the sewers to be lowered?

If the drains are blocking regularly then a steeper gradient may well help, (but if the pipes are too steep they may be more likely to block).

Try hammering a stake or crowbar into the ground to see if there is rock – or dig a hole by hand (good way of using up Christmas flab).

Rock breakers can get through the toughest crag but the harder the rock the longer it takes and the more expensive it is.

The depth of pipes (apart from giving the pipe a gradient) is only to prevent them being damaged. In a garden you can get away with a cover of 300mm over a 100mm pipe, or 600mm over a 150mm pipe. If the pipe goes under a road or driveway you will obviously need more cover. The material you backfill with is important.
 
thanks for reply. I am a complete novice when it comes to laying drains and totally lost when one is dealing with rockbreakers. Unfortunately I am no longer the strapping lad I once was, sport and age has taken its toll, hence no good with a crowbar. I am after a bit of knowledge so I dont get outlandish qoutes/reasons thrown at me. Your answer is fine and adds to the amount of knowledge I am gaining. Pipes to septic tank at the moment are above ground and the explanation given was " to avoid a deep dig because of possible rock" . I went back and found another manhole that has a drain running below the one that is raised! It is about a foot below surface.I was afraid the rock was impenetrable and I want to add an extension etc. The raised drain looks very unsightly.

Drain does not cross road so 300mm will be fine. I am assuming that wheover I get to do the work will know what to use as backfill or I will have found out by the time any work gets done. 6-8 weeks to get plans drawn, 2 -3 weeks to do plans, 3 months for planning permission!! cant get a quote until I have plans and so on it goes. I might as well get a degree in house construction etc while I am waiting. Should be ready in time for next world cup.

Thanks again for replying.

ebmitie
 
Wavin

The pipe manufacturers Wavin have a good website with a lot of technical information in easily readable form at: www.wavin.com.

You can become an expert on drainage by reading that!
 
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