Advice reqd on replacing cast iron svp

[N3mo]

All,

I have a cast iron svp running down the side of my house which I would like to replace.

Mainly becuase I am relocating my toilet and I would have to cut into the cast iron svp to add a new T-Piece.

My question is, how far below ground level does the actual SVP go? And if there is nothing holding it, does it just pull out of the ground?

Cheers

 

[Jackrae]

You could just pull it out but then you'd no doubt have a broken vitreous clay soil pipe , with the added problems that will give. You really need to dig down and find out how its connected to the vitreous clay and see if you can tease it out without breaking things. Some folk would give their right arm for cast iron soil pipes.

 

[N3mo]

Right! So its connected to a clay pipe. Wasn't aware of that!

Is it possible to fit a plastic t-piece on a cast iron after grinding out a small section for it?

Are CI SVP's not prone to failure due to rust? I was thinking everyone would want plastic as it is longer lasting?

 

[cotswoldbuilders]

You could cut it of about 150mm above ground, then fit a cast to plastic adapter, run the plastic back from there.
Take existing cast down from top, mind because its heavy.

 

[tony1851]

If it's an old CI pipe, you may find that rust-expansion has cracked the socket in the earthenware pipe below ground level.

If that's happened, taking out the whole pipe will also mean replacing a section of the below-ground drain = more hassle.

Best to cut off the pipe (using disc cutter) leaving as much as possible above ground level, and fit an adaptor for pvc to that.

But be careful as you will be cutting the CI pipe below its support socket meaning it could be free to move - and if you are heavy-handed you will still fracture the below-ground pipe.

Fix the new pvc pipe to the wall as near to the new connection as you can.

 

[N3mo]

Should I fix a new bracket to the CI pipe just below where I am cutting into to a) stop it vibrating as much, and b) help prevent any damage to the CI further down.

 

[dann09]

Whats going to happen to the "old" tee connection to the old WC?

Where in the S&VP's length do you propose to cut in a new tee?

Its always advisable to fix extra brackets when cutting CI - eg. even when we are removing the whole CI stack we fix extra brackets up to just below the first top section cut.

Dropping stacks is not DIY work.

 

[Hugh Jaleak]

If cutting into a cast stack halfway up it is vital to ensure the remainder above the new joint is secure. Cast is bl**dy heavy, removing even a small section may be enough to weaken whats left above. If it falls, then the result doesnt bear thinking about....

For safety's sake and peace of mind, at very least replace it all above the new joint, and ideally the lot to ground level.

 

[N3mo]

I dont really want to have to excavate below ground level as there is no problem with it. Moving toilet so will have a new pipe protruding through wall so will have to join it wherever the 2 will meet