[Nilu1978]

Hi I'm writing from montreal where recently we've been getting a lot of rain. My problem is how to get rid of roof water(flat roof) if my sewer backup valve is closed. This home was built in 1934 and roof and sanitairy drains are the same. Did not install a backup valve yet.
Thank you guys

[speedball1]

Hi i'm writing from montreal where recently we've been getting a lot of rain. My problem is how to get rid of roof water(flat roof) if my sewer backup valve is closed. This home was built in 1934 and roof and sanitairy drains are the same. Did not install a backup valve yet.
thankyou guys

It's against our code down here to discharge anything but sewage and gray water into the public sewer.
If I understand you correctly you're about to install a sewer check valve and you're asking how the run off from the roof will dissipate if the check valve's closed. Am I correct?
If the roof drain's connected inside to the house system it will all back up at the lowest fixture in your house. However, If the roof drain's connected downstream from the sewer check valve it will not drain until the check valve opens again but it won't back up into your home.
The solution to all this would be to disconnect the roof drain from your system and pipe the run off to a garden or a dry well. Good luck, Tom

[Nilu1978]

Thank you Tom. That idea did come to mind now I just got figure out do I tee it from under the roof and run it outside or do I do a sump pump setup next to the drain downstair so if ever the valve shuts and the water rises next to the pump it will automatically go on and take the water out in the yard

[speedball1]

Can you track the roof leader down to the ground where it can be disconnected from the sewer and diverted? Tom

[Nilu1978]

The problem is that the pipe which comes from the roof is the roofdrain,sanitairy drain and vent.It's just a 4 "iron pipe till the basement then in a cleanout then towards the city.