More commonly it cracks the base due to the extreme temperature difference in the base vs the grate area. Look for hairline cracks like this.Confession: the 15+ year old Oslo to be replaced by ( almost deciding ) a 'new/improved' VC Flexburn has been abused.
To you Jotul Oslo owners, DON"T CRACK THE ASH DOOR OPEN for firing. It will crack the top plate as we know too well.
Also, the enamel stoves don't need the yearly painting. look better long term, worth the extra money, clean up easy, which we did not do.
Cheap at the time the Oslo came.