krausen into air lock

[joemez]

I just made a sweet milk stout and after 12 hours the krausen has gotten so high it blew the airlock off. I cleaned it and reinstalled it.
My question is; is it normal for a high gravity brew like this to do that? My basement is about 70 deg so I am wondering if it may be to warm causing the fermentation to be too strong.

[fitz]

Both, gravity and temp are culprits here.
The warmer temps will speed up ferment, the added malt will also cause the overflow.
Usually people whom make high gravity beers either use an extra large fermenter, or the have a blowoff system set up to get rid of the initial volcano action. a tube from your airlock shaft to a pail of sanitizer works well.