Large krausen can result from several things. If you're fermenting warm (say 70+ F), then you may get a more active fermentation. The same goes if you're making a strong beer. Lots of sugar means the yeast will go nuts. Also, certain yeast strains are referred as "true top cropping". Beers fermented with such yeast may be more likely to cause cloggage. But yeah, it's normal. I've cleaned my fair share of beer off the ceiling after clogged airlocks. :cross: