TERMITE AND WOOD DECAY CONTROL TECHNIQUES
Figure 4-6. Slab-on-Grade Termite Control Techniques
Techniques for controlling the entry of termites through residential foundations are necessary in much of the United States (see Figure 4-6). Consult with local building officials and codes for further details.
Plastic foam and mineral wool insulation materials have no food value to termites, but they can provide protective cover and easy tunneling. Insulation installations can be detailed for ease of inspection, although often by sacrificing thermal efficiency.
In principle, termite shields offer protection, but should not be relied upon as a barrier. Termite shields are shown in this document as a component of all slab-on-grade designs. Their purpose is to force any insects ascending through the wall out to the exterior, where they can be seen. For this reason, termite shields must be continuous, and all seams must be sealed to prevent bypass by the insects.
These concerns over insulation and the unreliability of termite shields have led to the conclusion that soil treatment is the most effective technique to control termites with an insulated foundation. However, the restrictions on widely used termiticides may make this option either unavailable or cause the substitution of products that are more expensive and possibly less effective. This situation should encourage insulation techniques that enhance visual inspection and provide effective barriers to termites. For more information on termite mitigation techniques, see NAHB (2006).