Slab Pre-Treatment Coverage Calculator

The verified part is the coverage rate. For a horizontal pre-pour barrier the canonical rate is 1 gallon of finished dilution per 10 square feet (0.1 gal/sq ft) on normal/compacted fill. The part most online prose drops is the coarse-fill bump: coarse / gravel fill needs 1.5 gallons per 10 square feet because the product has to penetrate the gravel. This tool foregrounds it as a one-tap toggle:

coverage units  = slab area (sq ft) / 10
finished gallons = coverage units × fill factor
                 = 0.1 × slab area × fill factor
   fill factor   = 1.0  (normal / compacted)
                 = 1.5  (coarse / gravel fill)

concentrate (fl oz) = finished gallons × rate (fl oz / gal)
water (gal)         = finished gallons − concentrate / 128
bottles needed      = ceil(concentrate / bottle size)

Why the fill factor matters: a 4,000 sq ft pad on normal fill needs 400 gal; the same pad on coarse / gravel fill needs 600 gal — the 1.5× bump adds 200 gallons. Get it wrong and you under-buy.

Slab vs trench: this is the horizontal barrier — square feet × a per-10-sq-ft rate. The vertical trench barrier is a different unit basis entirely (linear feet × 4 × trench depth); use the termite trench gallons calculator for that. Don't conflate the two. Once the finished gallons are settled either way, the termiticide concentrate yield calculator turns them into bottles and cases so you know what to pull off the shelf.

Volume is only half of a pretreat. What the builder pays is a separate question, and the termite pretreatment bid calculator works it out per square foot from your own chemical, labor and drive figures. For the renewable warranty that usually follows the pour, the termite bond initial fee and renewal calculator handles the annual side, and framing that needs a supplemental surface treatment before it is closed in is sized by the borate wood treatment coverage calculator.

The slab rate (1 gal/10 sq ft) is verified against Pest Control Technology and Virginia Pesticide Safety; the coarse-fill 1.5× factor against Termike. The concentrate dilution figures (0.06% ≈ 0.8 fl oz/gal, 0.09% ≈ 1.2, 0.125% ≈ 1.6) are an illustrative default, not independently confirmed — they ship as an editable rate you override with your product label's figure before mixing. Areas are summed and converted through square meters internally; the gallons math runs in the rate's published imperial units so it reproduces the cited arithmetic exactly.