Chimneys are designed to do an adequate job of keeping the elements out. However, your chimney could be the cause of your leaking roof in heavy rain.
The brickwork of your chimney can often retain water which can make the roof leak in heavy rainfall. Brickwork, stonework, mortar, and lead flashing will decay over time and while it may be a small area, heavy rain will penetrate and cause leaks. ER are experts at chimney repairs and detecting chimney roof leaks and can carry out the following to prevent chimney leaks in heavy rain:
Chimney repointing
Chimney rebuilding
Chimney pot replacement
Chimney pot repairs
Lead flashing work
Installation of pots, cowls, and bird guards