What common materials are typically used for chimney repair?

The correct choice, which includes mortar, refractory cement, and masonry blocks, is specifically representative of the materials traditionally used in chimney repair. Mortar is essential for binding bricks and stones together, ensuring structural integrity and preventing water intrusion. Refractory cement is particularly important because it can withstand the high temperatures produced in a chimney, preventing damage from heat and ensuring safe operation. Masonry blocks are often used in the construction or repair of chimney structures due to their durability and resistance to the elements.

In contrast, the other materials listed do not possess the characteristics necessary for effective chimney repair. Steel and fiberglass may be used in certain roofing or construction applications but lack the thermal resistance required for chimney use. Wood and drywall are not suitable for chimney construction or repair due to their flammability and susceptibility to moisture damage. Lastly, while concrete may be included in some designs, plastic is not a material typically associated with chimney repair, as it cannot withstand the heat and conditions found in a chimney environment.