Yes, it's called a CRICKET !

A friend of mine and his wife recently replaced their roofing shingles after receiving notice from their Homeowner's Insurance Company that their home's asphalt shingles were approaching their 20 year anniversary. Not surprisingly, however, they (my friend and his wife) were informed that in order to maintain coverage on their home the shingles would need to be replaced. The Insured's sought out three roofing contractors for bids/comparative estimates, verified the credentials and reputation of the roofer selected for the job, and subsequently replaced the roof.

My profession for many years following retirement from the military was in the Insurance Industry. Although the county in which my homeowner friend and his wife resided inspected and signed off on the job as completed and within code, I was asked by the couple who owned the home to conduct an additional, informal inspection. They simply wanted to make sure via a third party inspection their roof was properly replaced. I explained that their request was not within my purview as an Investigator, but I did know a roofing contractor who was a good friend of mine with more than 30 years of roofing experience. I would make arrangements to have him inspect the roof. I would tag along to confirm authenticity of the inspection. Long story short, the roofing contractor's assessment revealed the job was properly completed with the exception of installing a 'cricket' behind the chimney on the downward slope.

Roofing crickets are installed to prevent rain water that flows downward from the roof's peak from seeping into the joint between the chimney and the roof; this water can immediately work its way onto and through roof decking and neighboring trusses (resulting in mold, mildew, fungus, and rot) through the attic insulation as that same water finally wicks its way into the drywall which makes up the interior ceilings and walls. The roofing company installed flashing rather than a cricket, but the cumulative effect of water flowing due to rain, melted snow, etc., for months and/or years can ultimately wear away the sealant used to make the flashing watertight. A cricket diverts rainwater around the chimney rather than splashing into it directly. Building codes vary from one county to the next, and although my roofing contractor friend was aware of this, his only comment was that the roof replacement was done properly and within code (flashing is allowed) although the owners' should have been aware of and insisted on installation of a chimney cricket. The gist of the story is this: serious projects require appropriate research, imperative if you want a proper (or desired) result.

Note: The roof replacement in this example was at the expense of the owners', not the insurance company. The installation of new asphalt shingles was considered to be maintenance related (worn out due to age) and not the result of a covered peril under the policy such as hail, wind, fire, etc...