Help with Macerator toilet waste pipe

[Barry378]

hi, I have recently purchased a property with a workshop in the garden which I am converting Into an office.

The workshop has a 110mm soil Pipe sticking out of the concrete base in a corner which I was told by the previous owner was put in place for a possible toilet in the future.

This soil pipe connects to a man hole by my house which is about 25 meters away. I plan on putting a toilet in my office, but I decided to test the soil pipe as something didn’t sit right with me. So I got a friend to poor water from a bucket to see what would happen.

The water eventually came to the man hole but was at a very slow pace and I am now not confident the gradient of this pipe will be enough to push human waste.

My plan now is to install a macerator toilet and feed the waste pipe through this soil pipe until it reaches my man hole?

Is this a good idea? Can it be done? If so what would be the best pipe?

Many thank

 

[Jackrae]

Macerator and your idea is wrong on so many levels
Why not repeat the test but this time use a lump of dog sh1t, a few sheets of toilet paper and a bucket of water equivalent to a full toilet flush (2 gallon ?) all poured in a fast as possible to represent a real flush + solids situation.

 

[Hugh Jaleak]

A wad of toilet paper will suffice to test the drain, no need to go looking for dog deposits! 110mm pipe is a far superior solution to a macerator, and I'd sooner be unblocking the pipe than a macerator any day of the week.

 

[Hugh Jaleak]

To add, you can get away with a little as a 1:100 fall on a new drain, pipes are smooth bore so the waste doesn't catch so easily. Given you'll probably have some sort of basin or sink for hand washing/making tea nearby, the extra flow from that will all help to wash the soil from the WC through. A belly (dip) in the pipe would be a bigger issue.

 

[Barry378]

Thanks I’ll give the toilet paper a test, Iv done some research and I believe the fall/gradient should be between 1:4 (1cm for every 40cm) which is 62.5cm fall and 1:110 (1cm for every 110cm) which is 22.7cm fall.

 

[Jackrae]

Don't forget that it takes time for water to flow through a pipe so don't expect an instant response between the inlet test point and the manhole - it could be several seconds. What you're looking for is a decent rate once the flow starts to appear.

 

[Hugh Jaleak]

The 1:40 was an old rule of thumb for 4" pipes back in the day. The Sanitary Inspector would come and roll a ball down the line once the drain was laid, if it got stuck, the drain failed and had to be redone.

Modern plastic pipework is much smoother internal bore as I said above, 1:100, (so 1cm per metre) is an absolute minimum fall, anything less and you will have issues. Likewise 1:40 for 4" pipework is an absolute max ideally. You're looking to achieve a 'Self cleansing velocity', whereby the water carries the solids with it. Too steep a fall and the water runs away leaving the solids behind, too shallow and the solids get stuck, leaving the water to seep away.

 

[just pumps]

The macerator would run out of puff over 25m.

 

[just pumps]

Macerator and your idea is wrong on so many levels
Why not repeat the test but this time use a lump of dog sh1t, a few sheets of toilet paper and a bucket of water equivalent to a full toilet flush (2 gallon ?) all poured in a fast as possible to represent a real flush + solids situation.

2 gal = 9l

 

[dilalio]

You could also put in a wc with a high level cistern... After all, our sewers were designed with these in mind.

 

[Jackrae]

You could also put in a wc with a high level cistern... After all, our sewers were designed with these in mind.

What difference will that make, the toilet pan disconnects the cistern, be it low level or high level, from the sewer ?

 

[HERTS P&D]

What difference will that make, the toilet pan disconnects the cistern, be it low level or high level, from the sewer ?

The force of gravity is greater.

A bit like removing an air lock from a downstairs basin rather than the upstairs bathroom.

Andy

 

[dilalio]

What difference will that make, the toilet pan disconnects the cistern, be it low level or high level, from the sewer ?

You obviously don't get much "head"

 

[Hugh Jaleak]

You could also put in a wc with a high level cistern... After all, our sewers were designed with these in mind.

I still find it an 'experience', on the odd occasion I come across one. A few of our sites still have one in use, Grandparents had one in their outside WC, (was still there when my Granny left that house after 40+ years to move into sheltered accommodation). Flush was/is shorter, more powerful and devastatingly effective. Nothing's would dare hang around with that behind it.

 

[dilalio]

I still find it an 'experience', on the odd occasion I come across one. A few of our sites still have one in use, Grandparents had one in their outside WC, (was still there when my Granny left that house after 40+ years to move into sheltered accommodation). Flush was/is shorter, more powerful and devastatingly effective. Nothing's would dare hang around with that behind it.

I'm a big fan of Bazalgette