Depth of Soil pipe to manhole?

[M_K]

Hi,

I am currently having an outhouse built, and want to ensure my builder is following best practices. I would appreciate a bit of advice about the soil pipe which runs from my outhouse, to the manhole at the side of my house.

The manhole is not very deep, but I am not sure if that is the max depth we can run the pipe to, or if it can go lower? The distance from outhouse to side of house is roughly 10-15 meters in total, and for the most part, it runs across my lawn.

I understand the need for a gradual slope, but want to ensure the soil pipe is safe from frost, and also in the future when I need to do some landscaping, isn't something that can be easily hit/dug to.

The waste pipe comes out of the outhouse at a visible height, so needs to go underground gradually. What is minimum depth which I should be expecting? Someone (unqualified) told me a meter is probably suitable, but I am hoping for someone more qualified to advise.


Thanks

 

[noseall]

Hi,

I am currently having an outhouse built, and want to ensure my builder is following best practices. I would appreciate a bit of advice about the soil pipe which runs from my outhouse, to the manhole at the side of my house.

The manhole is not very deep, but I am not sure if that is the max depth we can run the pipe to, or if it can go lower? The distance from outhouse to side of house is roughly 10-15 meters in total, and for the most part, it runs across my lawn.

I understand the need for a gradual slope, but want to ensure the soil pipe is safe from frost, and also in the future when I need to do some landscaping, isn't something that can be easily hit/dug to.

The waste pipe comes out of the outhouse at a visible height, so needs to go underground gradually. What is minimum depth which I should be expecting? Someone (unqualified) told me a meter is probably suitable, but I am hoping for someone more qualified to advise.


Thanks

250-300mm though BC will accept shallower if falls dictate.

 

[Exedon]

Most drains used to be laid with a fall of 1 in 10 times the diameter (maguire's rule)
Thus a 4in drain was 1 in 40.
Smoother plastic pipes have ment the fall can be reduced if necessary.
1 mtr over 15mts is way too much solids would be left behind.

 

[noseall]

solids would be left behind.

Myth.

 

[jeds]

Myth.

Bin skiing?

 

[noseall]

Bin skiing?

Yes, February.

 

[Hugh Jaleak]

I wouldn't worry about frost, unless you've a constant trickle of water going through the pipe, it's highly unlikley to freeze. 1:40 fall is ideal, but you can go as low as 1:100 if required, with modern smooth bore pipes.

Depth is governed by the existing drains, need to connect at same level ideally, (cant go lower obviously), to high isn't recommended either, as foul waste needs to enter a chamber properly, or it can cause issues down the line with blockages.