According to the National Association of Certified Home Inspectors (NACHI), a chimney cricket is a small peaked roof which is installed on the back side of your chimney to deflect water and debris from your chimney.
This business had issues with water backing up at the fireplace and leaking in behind the chimney. By installing the chimney cricket, water is diverted so that it no longer pools and causes problems.
See images below for basic layers and installation
For roofing installations and repairs in the Greater Nashville Area, call us for an onsite estimate 615-784-4628