An disused chimney should be protected from rain and weather effects. Masonry chimneys tend to absorb water leading to moisture and structural damage.
The reason for this is that the chimney cannot absorb water from the inside, but does absorb heat and if closed, no natural air circulation is provided and drying out occurs.
This leads to moisture penetration and floor damage, which can massively affect the building fabric.
Additionally, when installing a flue pipe from a condensing boiler in an existing chimney, care must be taken to ensure sufficient air circulation between the flue pipe and the chimney.
The PX-G-SCH fire resisting ventilation unit has been specifically developed for this disused chimney application.