More chimney leaks start at the crown than anywhere else. It's the most exposed surface on the whole structure — flat, horizontal, and taking every drop of rain, every temperature swing, and years of direct sun. Concrete crazes and cracks under that load. Once a crack opens, water goes where the crown was supposed to stop it, and the damage below is always more expensive than the crown itself.

The fix depends honestly on what's left. Surface cracks on sound concrete get prepped and patched — cleaned back to solid material so the patch keys in, then sealed across the full surface. A crown that's crumbling through gets rebuilt, because coating a failed slab is money spent on appearance — and where the brickwork beneath it has gone too, that becomes a masonry rebuild rather than a crown job. While we're at the top, the cap is right there too: a fitted chimney cap and a sound crown protect the same surface, and doing both in one visit costs less than two trips.