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Termidor Termite Treatment — 10+ Year Protection
Termidor SC liquid barrier treatment for subterranean termites in Southern California costs $800 to $2,500 in 2026, depending on linear feet of foundation. Trenching and soil injection of fipronil around the structure perimeter eliminates the entire colony within 90 days through the Transfer Effect, then provides 10+ years of soil-bound protection against re-entry. Ultimate Termite Control (CA SPCB License #PR7791) provides free pre-treatment inspection to confirm subterranean species before any soil work — Termidor is not suitable for drywood or wood-boring termites.
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What Is Termidor?
Termidor is a liquid termiticide with fipronil as the active ingredient. It has been used in the United States since 2000 and is the most widely used subterranean termite treatment, applied by CA SPCB-licensed (#PR7791) pest control operators to treat and protect millions of homes.
Unlike older termiticides that repel termites, Termidor is non-repellent — termites cannot detect it. They walk through the treated zone, pick up fipronil, and then spread it to nestmates through grooming and contact, eliminating the entire colony rather than just the foragers.
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The 4-Step Transfer Effect
Barrier Applied
Termidor is applied around the perimeter, under the slab, and in the crawlspace or subarea as specified by treatment plan.
Contact
Termites pass through the treated zone and pick up fipronil — they cannot detect it, so they don't avoid the treated area.
Transfer
Termites spread Termidor to every nestmate they contact through grooming and feeding — deep into the colony.
Colony Eliminated
The entire colony is eliminated within 90 days. The treatment zone remains active for 10+ years, protecting against future colonies.
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What Termidor Treatment Covers
Perimeter Trenching
A trench is dug around the full exterior perimeter of the structure. Termidor is applied to the soil at the base of the foundation before backfilling.
Slab Injection
For slab-on-grade construction, Termidor is injected through drill holes in the slab to treat the soil beneath.
Crawlspace / Subarea
Soil in the crawlspace is trenched and treated, protecting floor joists and substructure framing from subterranean activity.
Garage and Entry Points
Expansion joints, plumbing penetrations, and other entry points in the garage and perimeter are treated to close all access routes.
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Frequently Asked Questions
Is Termidor safe for pets and children?
Yes when dry — technicians treat outside perimeter and sub-slab areas, not living spaces. Once the treated zone dries, there is no risk to pets or children.
How long does Termidor last?
Termidor provides 10+ years of protection in most soil conditions. It binds to soil particles and remains effective even after rain.
Does rain affect Termidor treatment?
Termidor binds to soil particles — light rain won't wash it away. We avoid application during heavy rain but normal rainfall has minimal effect on efficacy.
Can Termidor treat drywood termites?
No — Termidor is a soil treatment for subterranean termites only. Drywood termites require fumigation, heat treatment, or orange oil.
How long until Termidor eliminates the colony?
Most subterranean termite colonies are eliminated within 90 days of Termidor treatment.
About the author
Written by Ryan Berry. Licensed California termite control operator (CA SPCB #PR7791), Anaheim, CA. Founded Ultimate Termite Control in 2007. 250,000+ inspections and 12,000+ residential customers across Southern California.
Last reviewed: June 19, 2026
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