Alison Wiles of 1st Associated Independent Chartered Surveyors says:  We recently inspected a pub called The Bitter End in Luton, Bedfordshire - such an apt name for a pub that had dry rot!  The dry rot was so extensive it resulted in the company selling it on at a reduced price.  The normal recommendation is to remove any timbers and burn them. 

The appearance of dry rot looks like a cobweb/network of fine roots and they eat the inside of the timbers first and the rot needs damp humid conditions.

We rarely see dry rot but when we do see it its not good news.  It does have a bias towards older properties but iits still fairly rare.  Pub in Manchester for golfer – had dry rot in the roof – so much it was excluded from the sale.  (photos from this one ,use these but not words).  John Maguire checked out this one. 

To the centre of this photo you can see dry rot.