[Runwell-Steve]

I have 5 200 Litre Sankey butts, I have never emptied them and they have been fine for the last 7 years with no protection at all from the weather.

[JayG]

I suspect that being made of plastic water butts are bound to become more brittle as they age and therefore more likely to split if the water freezes solid.

My 3 are OK (although 2 of them are nearly new.)

Makes mental note to think about emptying them if a serious and prolonged freeze-up happens again (so as good as forgotten already!)   

[realfood]

One of my blue plastic ones split at the bottom. The whole barrel froze to the bottom last Winter, the first time ever. It seems to depend on where you are in the UK.

[Gandan57]

As long as there is a small air gap at the top of the butt, when the water freezes it will expand upwards.

It may be prudent before a prolonged cold snap to draw off a small amount of the water.

[mumofstig]

some of the ones that froze didn't have any lids on, so I don't think that would help

[ex-cavator]

I think its a case of the degree of freezing. Plastic has a certain amount of 'give' and will normally withstand the expansion caused by a certain amount of ice - say, a couple of inches on the top & the little that may form around the outside during a normal UK winter's night - providing it's not old & become brittle, as they do. The extra precaution of adding a plastic drinks bottle or tennis ball to take up the expansion of the ice will help.

But, given the extreme and prolonged conditions of severe frost we experienced this year, when it is likely the entire contents froze solid, it is perhaps unsurprising that something had to give. If such conditions are forecast, it would always be wise to empty the container or to cover it / bring it inside 

[Weston grower]

Just to update you. I have 4 water butts all around 200ltrs. Put in plastic bottles and none split despite being full and temps of down to -12c.

Seems to show that not all butts are the same?

WG