Publication E-4
January 1977
Purdue University
Cooperative Extension Service
West Lafayette, Indiana 47907

PRETREATMENT TERMITE CONTROL
Gary W. Bennett, Extension Entomologist

Homes and other buildings can be "pretreated" at time of construction to protect them against termite attack. Pretreatment is relatively inexpensive and is highly desirable, especially in buildings constructed completely or partly on concrete slabs. Slab buildings are very susceptible to termite attack, and once infested, treatment is difficult and expensive.
Basically, pretreatment means laying down a chemical barrier to prevent termites from getting back and forth between wood and soil. Termites need wood for food and soil for moisture, so they constantly travel back and forth between the two. Wood in contact with soil is ideal for termite development. But where this situation does not exist, the insects build "shelter tubes" to span foundation walls and other parts of a building that separate wood from soil. Besides building the tubes on and over foundation walls, termites may also build them inside the walls if constructed of concrete blocks or other porous materials. In the case of slab buildings, the insects enter through expansion joints, cracks in the slabs, and openings for utility and sewer connections.
For effective pretreatment termite proofing, much of the chemical barrier may need to be under concrete slabs. Obviously, it is much easier to lay this barrier before the concrete is poured than it is afterwards.

AREAS NEEDING PRETREATMENT
For effective termite prevention, pretreatment is needed in four areas during construction:
1.	Treatment of the entire soil surface under any area to be covered with concrete, including garage floors, entrance platforms and filled porches.
2.	Re-treatment with additional amounts of chemical to the soil beneath those areas which lie adjacent to foundation walls, beneath interior walls, around sewer and utility openings and at other possible points of entry.
3.	Treatment of footings and backfill outside foundation walls and inside walled areas where there is crawl space. Accessible areas like these could be treated later, but it's easier to do it at construction time.
4.	Treatment of empty spaces or voids in concrete blocks.

APPROVED PRETREATMENT CHEMICALS
Chemical pre-treatment is accepted by the FHA as a method of termite proofing.
And most pest control specialists are equipped to pretreat according to FHA specifications, and can guarantee effectiveness. Contractors and others do not provide this guarantee.
Aldrin, chlordane, dieldrin or hepta-chlor are all suitable for pretreatment termite control. They are applied in liquid form (Table 1). It is necessary to dilute the chemical to obtain the correct concentration. Start with an emulsifiable concentrate, and read the label to determine the percentage of actual chemical present.
Then dilute with water to obtain the concentration suggested in Table 1. For instance, if you buy chlordane as a 45% emulsifiable concentrate, you would need