Safale s-04 spewing over

[Wobbler]

Is it normal for Safale s-04 yeast to cause the fermentation head to erupt quite so strongly?
Both recent batches of beer I've made using it have spewed over quite badly. The first was a stout which contained 2.5 lb of flaked barley, so I thought the flaked barley was the cause, but the brew I made a couple of days ago only contained pale malt, crystal malt and amber malt, and that did the same.
Any tips for preventing this would be welcome.

[oblivious]

That yeast for you, you could up grade to a 10 gallon fermentor

[Wobbler]

Using a 10 gal fermenter is the obvious solution, one that I'd already considered, but sometimes I have several batches on the go at the same time. Just thought there may be another solution.
I might stick to using Nottingham, which as yet hasn't spewed over.