Drainage plans for building regulations

[tvrulesme]

About to submit some drainage plans to building regs so I was hoping that I could get some views on here as to what they would likely object to as it's easier to make changes before submitting than after.

 

Assuming the gradients are within spec does anything look out of place or could be simplified here? The shower/sink waste goes into a gully because I can't get the 450mm above the invert of the soil pipe to connect a boss to

 

04-foundations-drainage.pdf

Edited May 12, 2022 by tvrulesme

[Conor]

You've too much detail. Mine was just dashed lines going in an indicative direction from each bathroom to the relevant stack. It's assumed that detailed levels, falls and bends will be worked out on site. 

 

I'm assuming it's a combined system? Why the bends between the gully at the bathroom and the soil pipe? That's the kind of thing to leave off the drawing and just show the pipes in a straight line.

[tvrulesme]

1 minute ago, Conor said:

You've too much detail. Mine was just dashed lines going in an indicative direction from each bathroom to the relevant stack. It's assumed that detailed levels, falls and bends will be worked out on site. 

 

I'm assuming it's a combined system? Why the bends between the gully at the bathroom and the soil pipe? That's the kind of thing to leave off the drawing and just show the pipes in a straight line.

Thanks Conor. I was trying to use it as an exercise in working out what parts I would need

 

It is combined yes. Yeah I'm going to rethink the gully part. I'll do it detailed for me and then simplify for building control once I've got it clear in my head

[Conor]

It's so much easier once you have each connection for the appliances installed and the ground opened up. We changed ours a fair bit and ended up saving a good 30m of pipe.

[tvrulesme]

1 minute ago, Conor said:

It's so much easier once you have each connection for the appliances installed and the ground opened up. We changed ours a fair bit and ended up saving a good 30m of pipe.

Kind of cheating because I already have the ground opened up. Needed a trench for moving a gas main so I just kept going.

 

 

 

My heights are all determined by an existing clay soil pipe which runs under the house which you can see at the end of the trench. Have to lay some waste for a shower this weekend which will be buried in a slab so I'm trying to do as much planning as I can before I do that

 

 

[nod]

28 minutes ago, Conor said:

You've too much detail. Mine was just dashed lines going in an indicative direction from each bathroom to the relevant stack. It's assumed that detailed levels, falls and bends will be worked out on site. 

 

I'm assuming it's a combined system? Why the bends between the gully at the bathroom and the soil pipe? That's the kind of thing to leave off the drawing and just show the pipes in a straight line.

Beat me to it 

Keep it simple 

planners arnt really that bothered 

Building Control is He or she is likely to change drainage plan 

[tvrulesme]

Close up of the existing clay. Top of the black gaffer tape is the same level as the DPC inside the house

 

 

[Conor]

It's so much easier once you have each connection for the appliances installed and the ground opened up. We changed ours a fair bit and ended up saving a good 30m of pipe.

 

Fyi building control only really care about the external drianage works and never asked to inspect out internal stuff. And I wouldn't worry about the depth. Keep it simple.

[tvrulesme]

2 hours ago, Conor said:

Fyi building control only really care about the external drianage works and never asked to inspect out internal stuff. And I wouldn't worry about the depth. Keep it simple.

 

Thanks Conor. One thing I am unsure of is if I can connect the shower waste to the gully underground using something like this:

 

 

 

I have the option to bring the shower waste either above or below ground level outside. Preference for tidiness would be underground but I don't want to screw myself over with the slab down if this is not allowed. Building regs approved document H state:

 

"A branch pipe discharging to a gully should terminate between the grating or sealing plate and the top of the water seal"

 

Which is what it looks like the above would do perfectly well

Edited May 12, 2022 by tvrulesme

[Conor]

12 minutes ago, tvrulesme said:

 

Thanks Conor. One thing I am unsure of is if I can connect the shower waste to the gully underground using something like this:

 

 

 

I have the option to bring the shower waste either above or below ground level outside. Preference for tidiness would be underground but I don't want to screw myself over with the slab down if this is not allowed. Building regs approved document H state:

 

"A branch pipe discharging to a gully should terminate between the grating or sealing plate and the top of the water seal"

 

Which is what it looks like the above would do perfectly well

Can't see how that would be allowed as you'd have grey water filling the gully. Was done a lot in the past but I can't seeing that being desirable. Can you not connect in to the soil pipe within the bathroom? Using a tee with 40mm boss on the top.

[tvrulesme]

43 minutes ago, Conor said:

Can't see how that would be allowed as you'd have grey water filling the gully. Was done a lot in the past but I can't seeing that being desirable. Can you not connect in to the soil pipe within the bathroom? Using a tee with 40mm boss on the top.

 

Unfortunately not. I would not be able to get the levels as it's a wetroom so the waste is lower than the soil pipe, particularly as it's a wall hung toilet which will discharge horizontally out of the wall.

 

Confused though, 1.8 states I can discharge to a gully if the pipe only carries wastewater. Would this not count as wastewater?