If the pillow blocks are under the surface you will not need to dig around them for you treatment. You will want to focus on treating outside around the structure for your trenching area so that the solution will absorb into soil enough to leave a residual where the termites are migrating from. Please let us know if you need more information.
When drilling holes for application of Termidor, you will need to come out 2-3 inches from the foundation and drill holes every 12" into the concrete along the foundation wall.
Termidor SC should be applied directly to the soil. It is recommended that you treat around each pier. You will mix at a rate of .80 fl oz. for each gallon of water used. Each 20 oz bottle will make 25 gallons of solution and treats 60 lineal feet of trenching. You could also treat the wood directly with Boracare. You will use a 5:1 ratio. This will last for the life of the wood.
We would also recommend that you check out our Termite Guide. It has very useful information and tips on how to treat and prevent termites.
Depending on the rate at which Termidor SC is applied, it can be applied 2-4 times per year for ant control.
When apply Termidor SC as a perimeter spray, apply at a rate of 1.5 gallons of solution per 1,000 square feet, using 0.8 ounces of concentrate per gallon of water. You should spray to evenly cover with a low-pressure coarse spray, so you do not need to drench the areas you are treating. Termidor SC should be used in a pressurized sprayer, not in any type of fogging or misting machine. For general perimeter treatments with Termidor SC, see the last two pages of the product label.