Unfortunately it is already a 5" liner that's being used. From what we can see it's the edge of the breezeblocks that have been installed too far into the flue that's causing the issue, don't think a scaper will have much impact on these.
thanks for your thoughts though.
Not sure where to post this so I'll put it here,
We have recently purchased a new house and are in the process of renovation.
We plan to have a wood burner in the front lounge, there is a large breast in the lounge and this continues through the house to a solid chimney etc.
The problem...