Where do cracks in masonry often appear?

Cracks in masonry can often appear in various locations due to different types of stress and movement within the structure. When considering the correct answer, it is important to recognize that both the masonry units and the mortar joints can be vulnerable to cracking.

Masonry units, which include bricks and blocks, can develop cracks due to factors such as thermal expansion and contraction, settlement of the foundation, or inherent flaws within the material. These cracks will typically traverse through the body of the masonry unit itself.

On the other hand, mortar joints, which are the spaces filled with mortar between the masonry units, can also be subject to cracking. This is primarily due to the differences in movement and flexing between the units and the mortar, as well as environmental factors such as moisture penetration or freeze-thaw cycles.

Thus, it is accurate that cracks can manifest both through the masonry units and along the mortar joints, making the third choice the most comprehensive and correct answer. Recognizing the potential for cracks in these different areas is essential for an effective home inspection to assess the overall integrity and stability of masonry structures.