Cracked drainage

[camerart]

Hi,

There has been slight ground movement which has cracked a couple of salt glazed pipes, where they connect to the downpipes. Here is a photo of one of them. It now has a 10mm gap between the cast iron down pipe and the fitting.

If I can remove the bend without damaging any other pipe work, then replace it. Does anyone think this is the best way to go?

The rest of the pipes and inspection chambers seem ok. I was going to replace all of the pipework up to the chambers, but as they are all concreted in, I presume they are ok. I will do a leak test on them also.

Cheers, Camerart.

Untitled

• camerart
• 14 Jul 2013
• 1

 

[dann09]

1. I cant see any 10mm gap. Is it at the back of the pipe?

2. Why not thoroughly clean off and wipe down the pipe and fitting. And post a new pic.

3. Whats the purpose of the board? Perhaps remove it before the photo?

4. The Cast iron pipe tight to a surface cannot be painted, and over the years its inclined to rot a lot quicker than the painted surface. Perhaps this should be examined?

 

[camerart]

1. I cant see any 10mm gap. Is it at the back of the pipe?

2. Why not thoroughly clean off and wipe down the pipe and fitting. And post a new pic.

3. Whats the purpose of the board? Perhaps remove it before the photo?

4. The Cast iron pipe tight to a surface cannot be painted, and over the years its inclined to rot a lot quicker than the painted surface. Perhaps this should be examined?

1/2 I've changed the photo.

3/ To hold the soil back from digging. I can move it a bit if it gets in the way.

4/ The cast iron hasn't rotted. I have 4X similar fittings along the house, from ground movement in the past.

 

[dann09]

Thanks for the new pic. Now i can see what you mean.

What makes you so certain that its "ground movement"? That bend was never properly bedded and supported.

Where is the other "cracked pipe"?
Are these soil or rain water pipes?
What is the white pipe, to the left, doing?

How far away is the manhole?
Do both damaged pipes run into it?

Its sometimes best practice to remove all salt glaze back to the MH. esp if more cracks are revealed, or suspected.

However, no other difficulties being revealed, you could cut the horizontal pipe below the bend - use a 9" A/grinder - and use a flexi connector(s) to tie in a new bend, properly bedded and supported.
The detached hub at the bottom of the CI pipe must be carefully knocked off.

 

[camerart]

Thanks for the new pic. Now i can see what you mean.

What makes you so certain that its "ground movement"? That bend was never properly bedded and supported.

Where is the other "cracked pipe"?
Are these soil or rain water pipes?
What is the white pipe, to the left, doing?

How far away is the manhole?
Do both damaged pipes run into it?

Its sometimes best practice to remove all salt glaze back to the MH. esp if more cracks are revealed, or suspected.

However, no other difficulties being revealed, you could cut the horizontal pipe below the bend - use a 9" A/grinder - and use a flexi connector(s) to tie in a new bend, properly bedded and supported.
The detached hub at the bottom of the CI pipe must be carefully knocked off.

I can tell the ground movement is all along the house, all the connections have moved down 10mm.

There are two manholes for two sets of pipes in different parts, they all have similar problems, I only showed one as an example.

As I said in the first question, they are all cased in concrete, so I think it they are all ok, except where they join.

The white pipe is gas and it runs along the side of the pipe in the picture.

I like the idea of a rubber join, especially if it moves some more!

Cheers, Camerart.

 

[dann09]

If you have similar 10mm drops on different elevations of the house, then its, as i said, due to the lack of bedding etc for the bend.

Surely, the whole house hasn't sunk 10mm?

 

[camerart]

If you have similar 10mm drops on different elevations of the house, then its, as i said, due to the lack of bedding etc for the bend.

Surely, the whole house hasn't sunk 10mm?

This implies that the house has risen 10mm, leaving the pipe. No it's the whole path that has dropped 10mm. Perhaps by poor bedding as you say, but there it has settled.

I'll fit some connectors and monitor it in 20 years, I'll be gone by then

Thanks. Camerart.

 

[camerart]

Ok, I fit a connector to the first pipe and that's ok now.

The second pipe might need cutting back, but as it's been cased in concrete, this will need removing and cleaning, so can fit a connector to add new pipe and fittings.

Does any one know the best way to remove concrete form salt glazed pipe work while doing the least damage to the pipe?

Cheers, Camerart.

 

[noseall]

Does any one know the best way to remove concrete form salt glazed pipe work while doing the least damage to the pipe?

I've mentioned this recently even talking about where pipes shear off or crack where svp's join salt glaze drainage.

There is no easy way to 'peck' the concrete from around a clay pipe as the concrete is often harder than the pipe itself.

Going at it in the direction of the pipe is risky so you have to kind of shear little bits off at odd angles until you have thinned it down enough to separate the last little bit away from the salt glaze.

My breaker has got a sort of dimmer switch whereby i can slow the whole action down. I suppose a roto-stop sds would be ideal for the more delicate chipping.

 

[camerart]

Does any one know the best way to remove concrete form salt glazed pipe work while doing the least damage to the pipe?

I've mentioned this recently even talking about where pipes shear off or crack where svp's join salt glaze drainage.

There is no easy way to 'peck' the concrete from around a clay pipe as the concrete is often harder than the pipe itself.

Going at it in the direction of the pipe is risky so you have to kind of shear little bits off at odd angles until you have thinned it down enough to separate the last little bit away from the salt glaze.

My breaker has got a sort of dimmer switch whereby i can slow the whole action down. I suppose a roto-stop sds would be ideal for the more delicate chipping.

Either way it sounds like a long job.

I wonder if acid is poured on the concrete, whether this would soften it, as long as it doesn't also soften the pipe. I'll give this a go 'Who dares wins Rodney'

Thanks, Camerart.

 

[noseall]

All you will end up with regards acid is a lot of fumes and a big lump of concrete remaining solid.

Not a prayer.

 

[camerart]

All you will end up with regards acid is a lot of fumes and a big lump of concrete remaining solid.

Not a prayer.

I'll stop praying then, and get pecking

Cheers, Camerart.

 

[Hugh Jaleak]

Gently does it, a few prayers thrown in may help! Was doing same last week, all was going swimmingly, then one false move and half the collar came away with the concrete. Luckily was able to salvage the job, managed to get enough concrete cleared from the pipe to get a coupling on. (Phew!)

 

[camerart]

Gently does it, a few prayers thrown in may help! Was doing same last week, all was going swimmingly, then one false move and half the collar came away with the concrete. Luckily was able to salvage the job, managed to get enough concrete cleared from the pipe to get a coupling on. (Phew!)

If you look at my initial photo, for reference. The second broken pipe had broken above the collar.

So looking down a broken ring of pipe in the collar, I drilled some cement from the join, then tried a chisel downwards. The collar broke right down and too far to salvage. So DON'T chisel between inner and outer, because the outer will fail first. (Obvious really, after the event )

cheers, Camerart.

 

[camerart]

After repairing crack, I did a leak test.

Now I'm going to dig it up and replace it all.

Thanks for your help, Camerart.