Cutting clay sewage pipe

zone

If anyone could help with this please. I need to cut a sewer pipe to make a new join. The pipe is about 130mm in diameter and very old. I think its made from clay or similar material. I have attached a picture below:


I have heard the best way to cut this type of pipe is with an angle grinder. Should i use a 4.5inch or a 9inch grinder? or is there another way? thanks

yan1

Yep, use the 4.5in grinder with a stone or diamond disc on it, shouldn't be a problem. You'll have to dig deeper and underneath the pipe where you're making the cut though.

latecomer

From the look of it a 4.5" disc wont go right through anyway but that said I have no idea whether a grinder is suitable for the job...

yan1

latecomer wrote: »

From the look of it a 4.5" disc wont go right through anyway but that said I have no idea whether a grinder is suitable for the job...

A 4.5" won't go straight through it. Neither would a 9" or 12". You need to cut all the way round the pipe externally, hence digging deeper and under.

zone

Thanks for replies. That is the same problem i was thinking of about not being able to get round the pipe.

From the pic do people think its possible to connect a Y joint or would i need to disconnect the old piece coming from the bottom left and use a bend connection instead? The flow direction is to the upper right. Ive added a couple of lines to my pic to show what i mean. The yellow line is showing the angle where the new pipe would be coming from.

yan1

Is the new run going to be in plastic? If so yes you'll just need a couple of the rubber adaptors to go from your clay to plastic at the two straight ends of the 'y' .

ormus

you just need to smash that pipe up. you wont need it again.
then insert the new plastic y-piece in its place.

you will prob need to dig the hole much bigger so that you can adjust/lift the two pipes, either side.

27col

Joints in clay pipes are notorious for leaking, if there is the slightest movement of the joint. If the rest of the pipe is kept well covered with soil to prevent movement, you will probably be ok., but I would not recommend that you thump the pipe too much, or move it. Quite a lot of these old clay pipe joints were put together with nothing more than a cement bag wrapped around the pipe and an application of almost neat cement to the outside. I had a lot of trouble when I built my house, trying to tie in with the old clay drain. In the end it was easier to replace a whole section between inspection pits with new plastic. Luckily the old pipe was very near the surface and not too much digging was required. Nice to see a good photo of the problem. Others please take note.

zone

Yes thanks for all the replies. The new pipe will be pvc. But i have only dug up to about half the run of the old clay pipe. To replace fully with pvc is so much more work i dont think my back could take it :eek: with all that digging. Its possible though. Please check the new thread ive created it has more detail on what im trying to do. thanks

mikey72

I used a 4 1/2 angle grinder last time I cut one.
I took off the shield, so with a bare disc, cut from the top down to about half way, then cut again to take out a "v" from the top, big enough to take the body of the grinder.
With the angle grinder I could now cut from the inside of the pipe, to get a neat edge.
Don't let go of the grinder without the shield, and don't stand over it.

plumb1_2

You can hire a pair of chain cutters, safer than using a grinder and a neater cut.
And you need a inspection chamber, so forget about putting a Y piece(branch) IN