Masonry materials are joined together with what substance?

• A. Mortar
• B. Cement
• C. Glue
• D. Grout

Answer: (A)

Mortar binds bricks, blocks, or stones together. It’s a plastic, workable cementitious mix—typically cement with lime (or cement-only in some mixes) plus sand and water—that is packed into the joints between units. When it cures, mortar forms a solid, load-transferring bond and helps seal against moisture, while still allowing tiny movements without cracking. Cement by itself isn’t used as the joint because it’s just the binder component and lacks the workability and bonding properties needed for joints. Glue isn’t suitable either, since it doesn’t provide the durability and moisture resistance required for masonry. Grout is used to fill voids or cores or to fill joints after the units are set, not to bind the units together during construction. So the material that joins masonry units is mortar.