Houses built partly or completely on slabs are prone to termite entry through which of the following?

Houses built on slabs are particularly vulnerable to termite entry through expansion joints, cracks, or utility openings because these areas provide direct access for termites to reach the wooden structures within the home. Termites can move easily through small fractures and gaps in a concrete slab, which can occur due to settling, temperature changes, or other factors.

Expansion joints are specifically designed to allow for the natural movement of the building; however, they can also serve as pathways for termites if left untreated or unnoticed. Cracks, whether they are from wear or structural issues, also create entry points. Additionally, utility openings—where plumbing, electrical, or HVAC lines penetrate the slab—can be neglected during construction or renovation, offering another access route for termites.

While roof vents, windowsill gaps, and foundation cracks may also present potential entry points, they are less directly related to the specific vulnerabilities associated with slab foundations. Roof vents primarily concern upper parts of the structure, and although windowsills can provide access, they do not directly relate to slab construction. The mention of foundation cracks is too narrow since it overlooks many other ways termites can infiltrate a slab-built home, such as through utility openings and other types of cracks. Thus, focusing on expansion joints, cracks, and