I'm doing quite an extensive renovation and just want to make sure my plan for the drainage venting is adequate.
The house is a mid-terrace and has a flat roof extension at the back, the roof of which I don't want to touch if I can avoid it (trying to limit costs as it was done recently), hence the somewhat unconventional drainage layout. The pre-existing soil stack runs up the back of the house and currently drops down the middle of my kitchen which is not a feasible solution.
The bathroom layout will be changing, and will have the bath under the window and the toilet in the corner furthest from the back wall. The waste from the toilet will run for approx. 1.5m in 110mm at low level along the wall with a 32mm connection from the basin and drop down internally in the corner into the below ground waste.
The bath / shower waste will be at the opposite end of the room and as such I am proposing that it drops at 40mm through the floor in order to get an adequate fall, and connects into the vertical stack mentioned above - the run will also be approx. 1.5m.
The boiler will be in the loft, the condense for which will drop through a 100mm boxed in section for the shower pipework and connect into the waste from the shower / bath.
Now comes the complicated part - venting the system.
Rather than continuing the toilet waste up and through the loft to vent to atmosphere, I'm looking to use an AAV to vent the toilet / basin float as I don't want to box in the pipe full height. The AAV will sit higher up than the basin.
Then to fully comply with part H, the system needs somewhere for the relief of positive pressure which I'm proposing could be done by continuing the waste from the shower / bath up the boxed in section and out vertically through the loft and roof.
If I were to do this, the boiler condense connection would be made in the loft - there is a tundish between the condense and boiler to prevent backflow.
Would this mean that the vent pipe would need to be increased in size to 50mm?
The house is a mid-terrace and has a flat roof extension at the back, the roof of which I don't want to touch if I can avoid it (trying to limit costs as it was done recently), hence the somewhat unconventional drainage layout. The pre-existing soil stack runs up the back of the house and currently drops down the middle of my kitchen which is not a feasible solution.
The bathroom layout will be changing, and will have the bath under the window and the toilet in the corner furthest from the back wall. The waste from the toilet will run for approx. 1.5m in 110mm at low level along the wall with a 32mm connection from the basin and drop down internally in the corner into the below ground waste.
The bath / shower waste will be at the opposite end of the room and as such I am proposing that it drops at 40mm through the floor in order to get an adequate fall, and connects into the vertical stack mentioned above - the run will also be approx. 1.5m.
The boiler will be in the loft, the condense for which will drop through a 100mm boxed in section for the shower pipework and connect into the waste from the shower / bath.
Now comes the complicated part - venting the system.
Rather than continuing the toilet waste up and through the loft to vent to atmosphere, I'm looking to use an AAV to vent the toilet / basin float as I don't want to box in the pipe full height. The AAV will sit higher up than the basin.
Then to fully comply with part H, the system needs somewhere for the relief of positive pressure which I'm proposing could be done by continuing the waste from the shower / bath up the boxed in section and out vertically through the loft and roof.
If I were to do this, the boiler condense connection would be made in the loft - there is a tundish between the condense and boiler to prevent backflow.
Would this mean that the vent pipe would need to be increased in size to 50mm?
) Others here certainly are.