Two Cisterns Cracked Within A Week

[Nick_Davison]

I live in a maisonette that has a downstairs WC and an upstairs bathroom.
On Sunday the porcelain cistern cracked when I was using the upstairs toilet, I put this down to me being 14 stone and quickly shut off the ball valve then popped to B&Q and bought and fitted a brand new toilet.
(I could not find a replacement cistern for the existing bowls bolt pattern.) I did notice that when I fitted the new toilet the floor was uneven, and dropped off a bit at the front of the footprint, so I made sure the new base was supported with some plastic shims where it needed them, thinking I had found the cause of the breakage....

But then....

About a hour ago, I was sat at my computer in the kitchen, and I heard a crack followed by the trickle of water. My initial thought was that this must have been the upstairs toilet again, and that maybe I had overtightened the cistern screws when I installed it, but this was not the case. In fact the trickling noise was coming from the downstairs WC and the cistern had cracked in pretty much the same place as the other one did. (Right along the rear right corner, top to bottom.) I am at a loss as to what could cause two cisterns to crack within two days of each other, I read online that it could be the building settling, but I live in a church conversion that must be over 300 years old, so I think that any "settling" the building had to do has long since been done. Could it be the hot weather?

It looks like I will have to go back to B&Q and pick up another toilet, but this is getting expensive...
The place is actually rented, but as a tenant I feel have a responsibility to maintain the property with regards to breakages like this that occur whilst the property is in my care.
It's a good thing too, because if I had not fixed the upstairs toilet I would now have no working toilet, and it would probably take the letting agency a few weeks to get someone round. Also I have no idea how the letting agency would react if I told them that two toilets had broken within two days, they would probably think I had been mistreating the property.

Can anyone shine any light on what could have caused this?

 

[Best]

As Whpes said, internal stresses can break the cisterns suddenly.
I saw a cistern (approx 20 year old) which had suddenly split open down the entire back corner. Each side of the top of the split was well out of line. Had to be under stress. Perhaps then all it needs is a change in temperature.
I think the cisterns that are glazed all the way around - back and all, are much stronger. Makes sense as the strength in a tile is often the glazing.
I wish all cisterns were glazed inside as well, like you got way back in time.

 

[Nick_Davison]

I came across something similar about 20 years ago.

Several pieces of sanitaryware in our warehouse spontaneously broke whilst lying on a pallet, apparently under no stress whatsoever. It happened over a period of a few days.

I spoke to a guy at the manufacturers, who said that it was caused by bubbles in the slip (water/clay mixture) forming air-pockets in the finished products. This captured air could become sensitive to sharp changes in atmospheric pressures, so a sudden drop on the barometer caused a pressure imbalance that could lead to cracking or shattering the whole item.

I have no idea whether its true or not, and I haven't come across the problem in years. A question for the OP though - was there a sharp change in the weather around the time that it happened? And were both toilets from the same manufacturer/look like they were fitted at the same time? If this is the reason, it would only make sense if the two were from the same batch of bubbly slip.

Hi Ray,

Its was a particularly warm weekend, and I really think you have hit the nail on the head here. Particularly since both the toilets were the same brand and design, and were very likely bought together, so they were likely from the same production run.

 

[Nick_Davison]

Does it wear a gimp mask and has a mangina ?

I hope not lol

 

[Ray Stafford]

Hi Ray,

Its was a particularly warm weekend, and I really think you have hit the nail on the head here. Particularly since both the toilets were the same brand and design, and were very likely bought together, so they were likely from the same production run.

Hi Nick

Interesting. My understanding was that it was a sharp drop in atmospheric pressure that caused the issue, rather than hot weather. However, I can see that its possible for direct sunlight onto the affected cistern creating a pressure imbalance between an air pocket and external air pressure.

Thinking about it some more though, I am not sure if the two circumstances are that close. Sanitaryware on our shelf by definition is new - and one would expect this to happen the very first time that the correct atmospheric conditions occurred - hence they broke even before we had time to sell them. If they have been fitted for more than a year or two, you would think that they had experienced most atmospheric conditions by now.

Just thinking aloud - I suspect that this is one of those things that you will never be able to pin down.

If you still have the cisterns, it might be interesting to inspect the broken edges, and see if there is any sign of an air pocket?