This is an example of a concrete brick chimney. It is a triple flu with a cap that has a drip edge. The old chimney had a cap but no drip edge. The drip edge allows the water to drip off of the cap and not run down the side of the chimney. The reason for this rebuild was because of severe water damage to the side of the chimney. Single flu's are the easiest to install. This chimney was done in less than a day.