What to do with cast iron rainwater drain inside building

[Jonathan Porter]

In an old listed building, in the basement we have a cast iron pipe, not a soil stack its a rain water drain pipe. It leads through the wall which is about 600mm thick and was leaking badly internally in the wall. It turns out there is a 300mm crack in the pipe. It is fed by a lead pipe inside the building, leads through the wall and outside turns down through 90 degrees and just exits into a drain.


Because its old cast iron pipe with traditional joining methods, it could be difficult and costly to replace like for like (as is required in listed buildings I believe?) one suggestion is to wrap the pipe in denso tape.


The room is to be made into a brand new bathroom with brick, metal, plasterboard, skim/tile placed over the top so we don't want it leaking again in a few years.


Is denso tape a viable repair option for these circumstances?


Is there another product, or a better way to do it?


Thanks
Jonny

 

[Best]

Do not repair it with Denso tape. It is a greasy tape that oozes grease with heat especially. It risks drying up eventually.
If it is to be all hidden I would get it fixed permanent, should that mean replacing part of it

 

[snowhead]

I
Because its old cast iron pipe with traditional joining methods, it could be difficult and costly to replace like for like (as is required in listed buildings I believe?) one suggestion is to wrap the pipe in denso tape.

If the Building Listing stops you replacing the pipe for plastic, then the same listing will stop you from wrapping it (madness) or boxing it in.

Speak to the Listings person , they'll advise.
Unless it's Listed Grade 1, I doubt you won't be allowed to replace it for plastic.

 

[Robert Tyrrell]

When I were a lad, and just starting in this game, I used to come across this sort of thing all the time - splits in cast iron pipes that is.
The way the we used to make a 'permanent' repair was to heat the pipe up so that it expanded, and the split opened a bit, then get some lead solder and hammer it in (Carefully). The pipe cools and contracts around the solder and seals the leak.
There's obviously a bit more to it than that but that's a quick way of explaining how to repair a cast iron pipe in a listed building.
It's a lot better than 'Denso' tape in any case.

 

[joni os]

Propose to Listed Building Officer that you cut out cracked section of pipe, replace with new cast iron, joined both ends to existing with Viking Johnson couplings. Won't look pretty but maintains maximum amount of original feature.

 

[rpm]

Even if you managed to repair the 300mm cracked section of pipe that`s in the wall what`s not to say it will leak somewhere else in time when it`s all covered over?

 

[lame plumber]

being more practical, if the listed folk cant see it they cant worry, whip out the old cast, replace it with plastic or if your worried aluminium alloy type pipe work. Where it exits the building, paint it black, heritage officer wont even notice.

Just to prove how stupid they can be, I was a bursar at a school where everything was listed. We had a proper old style plumber who decided in his spare time to make up some lead hoppers and downpipes to replace the plastic on the front of the main building, so it matched other lead rainwater goods on the site. Council heritage officer told us to replace it with the original downpipes, as per the listing order, which we had just removed, the bursar told her to feck off (my own words 🙂 ), so loads of letters went back n forward, I like an argument, until they asked us to prove what was there in the 1890s, so we dug out some early photographs, the ones the plumber had also used to get the logos of the family correct on the hoppers and sent them off. Then the council officers marched in one day demanding we reinstate the water goods iaw the phots, so I took the group of numpties outside, pointed at the new hoppers and downpipes and went back in. They all hopped in their cars 10 minutes later and buggered off, never heard from them again 🙂

 

[chris watkins]

Just replace the section through the wall with new cast iron it will last another 100 years. [DLMURL]http://www.saint-gobain-pam.co.uk/assets/docs/sdr/Timesaver_Manual_2012.pdf[/DLMURL]

Page 62 if you need the traditional look outside.

 

[chris watkins]

Cast Iron Style Soil System | Cascade | Brett Martin

Or if you must use plastic at least this stuff will look-e-likely for a few years.

It will all depend on what you have outside in the way of the bend / outlet?

Forgot to ask what size & shape is the existing pipe.

 

[plumben]

Can't you just get the drain lined where they place a lining inside the drain like what they do to fix broken drains without digging up the ground?

 

[Robert Tyrrell]

Can't you just get the drain lined where they place a lining inside the drain like what they do to fix broken drains without digging up the ground?

Now that's a good idea 🙂

 

[chris watkins]

Now that's a good idea 🙂

Trouble is Robert they need access at both ends to line drains, so for a 600mm length through the wall is it going to be worth it? might as well replace I would think.