Termite Barrier Cost Calculator

This calculator prices out a termite barrier along your foundation's linear perimeter, treating chemical and physical barrier systems as genuinely different cost structures rather than variations on one number. For a chemical (liquid termiticide) barrier, it estimates solution volume as 0.4 gallons per linear foot per foot of trench depth, priced at $2.50 per gallon of diluted termiticide, then adds trenching labor at a $5/linft base rate. A physical barrier — stainless steel mesh or a granite-particle system like Granitgard — is priced instead at a flat $4.50/linft material rate with $4/linft installation labor, and the "combined" option simply sums both systems along the same perimeter. Labor for both paths is scaled up by two multipliers: a 1.6x penalty when the structure is existing rather than new construction (landscaping, hardscape, and utilities all make trenching slower), and an access-difficulty multiplier that adds 25% per step of difficulty above "easy." Existing structures also add a drill-and-treat allowance, assuming 20% of the perimeter runs under concrete that needs drilling and injection at $15/linft.

Backfill cost is computed from actual trench volume (perimeter times width times depth) converted to cubic yards. The annualized-cost figure divides total cost by each system's typical warranty — 5 years chemical, 25+ years physical, 10 years combined — which pushes physical's per-year figure far below chemical's even though physical's material rate is the higher of the two. That warranty math isn't the only place physical pulls ahead: because chemical's solution volume (and the backfill that goes with it) scales directly with trench depth while physical's material and labor rates stay flat regardless of depth, a standard 4-foot trench already makes physical the cheaper system on raw total cost too, not just per warranty-year. Chemical only wins a straight total-cost comparison at shallower trenches, where less solution needs mixing and hauling — past roughly 3 feet of depth, the added termiticide volume outpaces physical's flat material and labor rates and chemical becomes the pricier option outright.