Do Salt Glazed waste pipe joints commonly leak?

[tpb1975]

Do the joints between Salt Glazed ground pipes commonly leak? I've just had to replace a broken section including gully. After running water through the new gully and connecting pipes, it appears that the next salt glazed joint is leaking bad enough for it to come through the clay pipe bedding back to where I've been working.

I should have figured this might have been an issue as there was a section of nasty black clay under all the junctions I was working at. But not an issue until I started digging below the salt glazed pipe level to create a pipe bedding for the plastic pipe. The house is on clay so I'm guessing the water didn't really go anywhere.

Should I dig down to the next section and replace it with plastic? Or dig to the joint and surround the joint with concrete or cement? I'm a little concerned that if I dig down and cut out the next section, the next section down will just do the same.

 

[ree]

In other words, you dont know where its leaking from - could be one leak or various leaks.

Depending on how far it is between the gulley and the nearest manhole, why not dig up all the salt glaze pipe, and replace with your chosen material?

I suspect that you may be causing difficulties for yourself - because glazed pipes and gullies dont just break, neither do they commonly leak - far from it.

Dont go pouring or encasing with concrete. Post a couple of pics of what you've got.

 

[noseall]

You are more than likely disturbing the joints as you work on each section of pipe. However, they do leak as the mortar joints are not as flexible as modern connections and are prone to fail if there has been any movement.
I have lost count of the miles of this stuff I have renewed over the years.

 

[JohnD]

I don't think "leak" is the right word.

They crack and break.

IME they are usually cracked at the bend or joint on the yard gully, and at the rest bend where the vertical pipe turns horizontal. Both of these are next to the house, where the house settles a bit and the ground doesn't, and there is no flexibility or give in the pipe or joints.

If you are in a place where the houses are not built on clay, and where the houses were not all shaken up by bombing in 1940-44, then your experience may be different.

 

[Hugh Jaleak]

I've come across runs of these old salt glazed drains, that have just fallen apart when disturbed. It appears the joints were merely sealed with clay when the drain was laid, and root ingress can often be a problem. Where feasible or required we pulled the old stuff out and relaid with new.

 

[tpb1975]

Dug out another section of the salt glazed and it just came out. Looks like there's been enough movement over the years for the cement to have come loose. Most of it covered but not the bottom. Interesting to see it wasn't packed out with any form of gasket (tarred rope). The problem is each section isn't that long, so when you dig down 100mm at the connection to get the minimum recommended pipe bedding for the new stuff, you're lower than the next connection down the line. So the water was coming back into the trench. Fortunately the next connection seems to be better. I suspect many have gone but it's all built on thick clay, so guess it's containing any leaks. I have to dig twice, to get the clay out and then to get the clay off the spade

 

[ree]

"it wasn't packed with gasket tarred rope" - back in the day most leaks we found were exactly because the hub had not been gasket packed or sometimes that pure cement had been used as a sealant instead of a semi-dry mix of S&C.
Actual cracked or broken salt glaze was often because of mechanical damage.

Many short sections of salt glaze might indicate a gradual bend or curve in the pipe line.

 

[tony1851]

Salt-glazed drainage ware is one of the few old, traditional materials which are not as good as modern equivalents.
Mainly, they are too rigid and cannot adjust to even slight ground movement.

Cast iron soil pipes also cause problems when they go into salt-glazed sockets - over time, rust builds up on the iron, expands and cracks the socket.