Garage roof repair ….Advice needed

Morning Y'all,

Need a bit of advice re our garage roof …..

We have an en bloc garage at the foot of our garden. Circa 1950 concrete block and asbestos panel roof (corrugated).

From where the asbestos flexes through temperature extremes we need to seal a section with a flexible tar(?) like product as what we have used up until now has split due to the flexing.

In an ideal world the roof would be replaced but it is just not a priority at present.

Can anyone suggest owt?

I recommend Evercryl. Should be available at most builders merchants. Really good stuff.