What type of cover is required for cleanout openings according to IRC standards?

According to the International Residential Code (IRC) standards, cleanout openings in chimneys and vents are required to have a non-combustible cover. This requirement is in place because cleanouts are typically located in areas that could be exposed to heat and combustion byproducts. Using a non-combustible material ensures that the cover can withstand high temperatures and potential fire hazards without igniting, thus maintaining safety in the environment where the fireplace or chimney is used.

The selection of non-combustible materials, such as sheet metal or brick, helps to reduce the risk of fire and ensures that the cleanout opening remains functional while providing adequate protection against debris and animals. Properly installed covers also help to prevent downdrafts that can bring smoke and other contaminants into the living space.

Other materials, such as wood or plastic, would not be suitable due to their flammability, while while metal covers could potentially meet safety standards, the IRC specifically references non-combustible materials to emphasize enhanced fire safety.