It's called flashing. You'll need to get up on the roof and have a look. Could be a simple matter of just repointing it back into the brickwork or replacing it. If you have a remote controlled helicopter and a digital camera, pehaps you could post us a picture
I did get up on the roof and (i think ) i fixed it. There is no flushing tape it is cement around the chemney. So i put new lay of cement.... i am waiting for rain to check it.
If you need to find a tradesperson to get your job done, please try our local search below,
or if you are doing it yourself you can find suppliers local to you.
Select the supplier or trade you require, enter your location to begin your search.
Please select a service and enter a location to continue...
Are you a trade or supplier? You can create your listing free at DIYnot Local