Cob roofing?

[GENTH, APRIL]

Hi,

        I've heard of earthen roofing.  To prevent the devastating fires
possible with thatch rooves, could a network of wooden planks with light
bricks of mud laid ontop of them work, like wattle and daub structures do?
Add to this a thin layer of mud on top and then thatching on top of that?
Would this approach cause too much stress of weight on the wood planking?
Too much work? Implausible?

-April