What part of the chimney is often made with a cement wash?

The cap of a chimney is typically made with a cement wash to enhance durability and aid in water drainage. The function of the cap is to prevent water from entering the chimney, which can lead to various issues such as rust, deterioration, and potential structural damage. The cement wash creates a sloped surface that directs water off the sides of the chimney, thereby protecting the underlying materials from erosion and damage caused by moisture.

The other components, while they are essential to the overall functionality of the chimney, do not typically involve a cement wash in their construction. For instance, the flue is primarily used for venting smoke and fumes, while the crown serves as a barrier and seal against water but is not the same as the cap. The chimney shaft refers to the vertical structure that encloses the flue, which is usually made of masonry or other materials to withstand heat and is not specifically constructed with a cement wash like the cap.