How to block soil pipe

[Fran Faulkner]

I have knocked our downstairs bathroom and kitchen into one. (Don't worry, I have a new upstairs bathroom!) The soil pipe from the old loo goes vertically down through the floor, and then bends to meet the drain outside - I can raise a manhole and see where it joins the drain.

I've made a temporary seal with a sort of rubber bung from B&Q shoved in the top of the pipe - it kept debris from falling down and getting into and blocking the drain. To permanently seal it (don't want any possibility of whiffs or worse coming up into the new kitchen from the drain.) I was intending to pour a bag of 'post-mix' concrete down the pipe, then add water. I'm worried the cementy water will seep through before the concrete goes off and block the drain. I'd be grateful of any advice as to the best way to block the pipe!

TIA

 

[heating tech]

if you wish to block off the reduntant pipe i have used a small amount of news paper to block the hole and then used cement to create a plug,bench the cement over the collar so that it will be a solid lump and then it won't be able to slide down the pipe use you rubber bung at the other end in the pipe that exits into the manhole cover ,then over the years when the news paper rots away it will not block up the drain downstream

hope this helps

if you are having this as a kitchen make sure you abide to the building regs having ventilation in the kitchen

all the best

gary

 

[chrishutt]

As long as you make sure the drain pipe is sealed below the cement, you can do what you propose. Don't mix too much water with cement, then the water shouldn't seep through your temporary seal below.

 

[ChrisR]

A squirt of builders foam would stick very well to wet sides and make a watertight seal. A cap of concrete would be appropriate I'd have thought, though I can't think right now of anything which would shift the foam.

 

[Fran Faulkner]

Thanks all - I think I'll use ALL your suggestions - put the rubber bung in the bottom of the pipe (lean down through the manhole - I can just reach), then squirt some foam down the pipe from indoors, followed by some water to make it go off. Then the post-mix concrete and water.

 

[breezer]

A squirt of builders foam would stick very well to wet sides and make a watertight seal. A cap of concrete would be appropriate I'd have thought, though I can't think right now of anything which would shift the foam.

it rots over time

 

[ChrisR]

it rots over time

Even if in the dark?

 

[breezer]

it rots over time

Even if in the dark?

dont know i cant see