garden wc 70 feet from soil pipe

[jocie]

Is there a satisfactory way of me installing an outdoor w.c. about 70 feet horizontally from my soil pipe, without using the "normal" macerator which pumps into a quite small diameter outlet . I would prefer to use a larger diameter macerator/pump outlet pipe ( but not a full size soil pipe) to reduce the risk of blockages. The w.c. outlet would be about the same level as the entry to the house soil pipe 70 feet away, in an almost straight line.

 

[Hugh Jaleak]

Running it horizontally above ground is unlikely to work very well, if at all. Underground may be feasible, if you can get sufficient fall on the pipe, use 40mm waste. Once the unit has pumped the waste out, it should run under gravity to the sewer. However, you'll need to achieve sufficient depth on this pipe to prevent damage and/or crushing.

 

[jocie]

Thanks Hugh. I was aware of what you are advising, but I didnt express my question very well. I intended to allow the pump/macerator system to raise the waste up to the most appropriate height for the beginning of the run. I want to have the pipe run attached to our boundary fence and almost the entire length will be hidden from view behind my wife's well stocked borders . I just wondered if it made sense to have the run in a larger diameter such as 50 ,60, or 70 mm to minimise the risk of blockages, or to create less work for the macerator/pump. I have never used a macerator before and would be glad for any advice on the best or simplest or most reliable system. I plan this as a late spring job.

 

[Hugh Jaleak]

Must warn you that macerators are the devils own work. When it goes wrong (not if) it is a filthy job to fix...... Basic golden rule is nothing to go through it that hasnt been through you! (Should handle toilet tissue but nothing else!)

Should be ok in 40mm, upgrade to 50mm half way. Once its lifted the discharge to the appropriate height, it should then run by gravity to the sewer. Fit plenty of access points along the run, and insulate it well for the colder months. (A dripping or letting by flush valve will cause the pump to kick in at frequent intervals, if the outlet freezes you'll have a flood if not knackered macerator.....) Manufacturers instructions should be followed to the letter.

If you really want simplicity and reliability then sorry, but has to be a 4" drain the whole way.

 

[jocie]

Thanks again Hugh for your advice, based on which,together with my further online research today, has made me decide to try hard to design my project to enable use of 4" soil pipe all the way !!

 

[Hugh Jaleak]

Worst part is the digging! Backfilling slightly easier. Need to ascertain the depth of the existing sewer you wish to connect to then see if a suitable fall is achievable between that and the proposed new WC position. 1:40 is a rule of thumb, but with extreme care 1:100 is possible.

Entire drain neeeds to be accessible for rodding should need arise, if you cannot connect into an existing chamber then may need to fit on at proposed connection position. Bed and surround pipes in peagravel, and keep initial layer of backfill free from any big lumps or stones. Anything else feel free to come back and ask, but 4" drain is fit and forget, it'll handle most of what gets flushed down a WC!

 

[ian323]

Hi Hugh, thanks for your comments to Jocie. I have a similar plan, have considered the fall over a shorter run of 20 feet. My question is that I want to run the macerator pipe (40mm) into the sewer which has a regular square cover flush with the patio. Am I ok to break into the brickwork just under the cover? The soil stack pipe is further up the garden and any pipe would foul a gateway. Thanks Ian