This is interesting, the log burner is one of those fiercely efficient ones you have to buy to get a grant from the Frog state, not that we did, cos they only pay the sub by reducing your income tax! Which of course we don't pay, nevertheless it makes it much more economical.You get a fallout on the roof in the Leeward of the prevailing wind depending on your deg of pitch this can cause a delamiation of roof tiles as most are now only surface dressed I prevent this by spraying every 4yrs with a sealer the fallout is very acidic
Therefore there is very little smoke as we burn dry hardwood all the time.
The chimney is very low and has a flat top, the pitch is about 30 degrees and I'll put pics up so you can see the type of damage and it's situation in relation to the chimbley. I'll also have a look to see what it is like on the south side. The tiles are the typical, provencal-type, wavy, earthenware numbers.
And yes the prevailing wind comes from the west so blows across from the chimney which is right on the westward end.
Pics to follow.
Ta mate.