The dangers of a faulty chimney
Whatever form of heating you use – coal, gas, oil, log-burning, etc. – an efficient chimney flue is essential to you… for both economy and health.
Inadequate insulation causes condensation, which combines with the fumes to produce sulphuric acid.
This attacks the brickwork, eating into the mortar resulting in dangerous joint leakage, eventually leading to the total collapse of the chimney stack