I have wet walls under two cills and discovered woodworm holes could this be due to the cills?
Woodworm infestation is frequently associated with timber decay so in theory it is possible that wet rot in the cills has created favourable conditions for a woodworm attack. The presence of flight holes on its own does not necessarily indicate a woodworm problem – the infestation may no longer be active. The fact that the walls are wet suggests a more serious problem – perhaps the cills are not fulfilling their purpose and enabling rainwater to drain away clear of the masonry. On the underside of the cills there should be a weathering groove which is designed to do this. The priority is to rfind the cause of this dampness and rectify it.
