Before you build that new home, the builder generally works a deal with a Termite Company to treat the soil beneath the slab is poured. There are lots of things that can go wrong and lets talk about a few.

1. Scheduling conflicts and nobody shows up for pretreatment, you may or may not know this happens but it does.
2. The builder uses the cheapest termiticide.
3. After the builder does all the work and just after the termite company shows up and treats the soil, somebody decides that there are several pipes in the wrong place. Nobody calls the termite company with an update.
4. After the termite technician treats soil, the building folks or plumbers walk over the product. I can’t tell you how many times this happened to me, I go crazy and they look at me like – who cares.
5. The concrete people don’t remove all the form boards.
6. The termite technician measures or calculates the square footage incorrectly.
7. It was raining or rained very soon thereafter.

I run into various slabs or foundations that bewilder me on why there are termites so quickly into the houses life. Hire a reputable company and don’t fall for scams that sell pretreats for 3 or 4 cents per foot. Use or insist on a quality termiticide, if you use a quality product and company a pretreat should last. I was going to give a approximate number of years but I’m hesitant because of factors including soil, location of US and rainfall or water table heights. In Arizona I would think that a well performed with a quality termiticide  under the slab should last 15 years, the outside maybe, maybe 5  – 7 years. (my opinion)