What Subterranean Termites Damage
Eastern subterranean termites in Missouri feed preferentially on wood with elevated moisture content — sill plates in contact with or near soil, floor joists in poorly ventilated crawlspaces, wood framing adjacent to plumbing leaks, and structural wood in contact with exterior grade. The sill plate (the lowest structural wood member resting on the foundation) is the most commonly damaged element in Missouri homes because it is closest to the soil and often in direct or near contact with the foundation's moisture. Subfloor sheathing, floor joists, and wall bottom plates adjacent to the sill plate are the next priority areas. Above-grade damage — wall studs, window frames, interior woodwork — occurs in established, long-running infestations or where moisture from roof or plumbing leaks has created secondary entry.
Cosmetic vs. Structural Damage
The critical distinction in termite damage assessment is whether affected members retain structural integrity. Cosmetic damage — surface galleries in a sill plate that still has substantial solid wood remaining — can be treated and monitored without immediate repair. Structural damage — a sill plate reduced to galleries with no solid wood remaining, or floor joists with significant cross-section loss — requires repair in addition to treatment. The probe test is the field standard: a sharpened tool (screwdriver or awl) should not penetrate wood under light to moderate pressure. Wood that the probe penetrates easily, or that shows hollow response when tapped, has lost structural value. D&D Pest Control provides termite inspections and treatment for Franklin County and rural Missouri — visit ddpestcontrolmo.com.