This can manifest in a number of ways such as.
Water running down chimney breast in attic.
Water could get into the attic or above your ceiling and either drip to the floor or roll along the stringer the long piece of wood that spaces out the roof trusses and runs the length of your house.
1 water runs down the flue.
Every step has decrease the amount of water but i can t get that last bit.
It hangs over and down about 2 inches off the top of the flue.
2 water runs down the brickwork inside the house or attic.
The chimney crown covers the top of the chimney to help protect it from the elements.
Broken or blocked gutters can cause rainwater to filter and collect in unwanted areas causing water ingress and damp in your chimney.
If you have a broken gutter in heavy downpours water can run down the face of a wall and seep into any splits or cracks in mortar presenting as damp in your chimney breast.
Well the salts accumulated on the roof timbers are there due to years of tiny water ingress and condensation on the underside of the roof slates.
Further diagnostic inspection is needed.
But efflorescence might also mean that water is running inside of the chimney flue or chimney structure.
Efflorescence on a chimney might be just cosmetic as wind blown rain wets the chimney sides and leaches out mineral salts which remain white on the masonry surface of the chimney.
More on this later.
I still have a small bit a water coming down during occasional heavy wind and driving rain.
This portion of the chimney prevents water from entering the flue but also prevents wear and tear on the masonry.
Repeated wetting and evaporation has concentrated those seen here.
3 exposed chimney brickwork gets damp and white lime deposits form on.
Building faults that can cause chimney damp damp patches on the chimney breast brown or yellow marks on the walls and ceilings surrounding the chimney often point to damage caused by a water leak or building faults such as inadequate guttering missing roof tiles poor flashing details and absorbent masonry.
The slanted crown should provide a downward slope that will allow for water runoff.
