Specify a Termite Shield System

A termite shield is placed between a masonry foundation and wood framing to prevent termites from gaining access to the wood framing components. Termite shields (Figure 7–2) must be of termite-resistant materials such as metal or concrete. Some termites are able to chew through plastics and thin metals. Also, any seams in a termite shield must be soldered or otherwise sealed.

Since termite shields require a high degree of care in installation, they are best used in combination with soil treatment. They should always be used when there are potential hidden pathways. Construction types known to create hidden pathways for termites include slab-on-grade (except monolithic slabs of good construction), masonry construction, and brick veneer construction.

Hidden pathways allow termites access to wood materials through pathways that cannot be detected during periodic inspection. When there are no hidden pathways in construction, subterranean termites can be easily detected by the presence of shelter tubes or tunnels that are made of mud to protect them from light and keep them moist. Because termite shields are difficult to install on slab-on-grade construction or split-level construction, other methods of termite protection (e.g., soil treatment) are generally preferred for these types of foundations. It is also noteworthy that termites can gain hidden access through cracks as small as 1/32” wide. Therefore, if concrete is used as a barrier to termites, it should include welded wire fabric or sufficient reinforcement to control cracking. Examples of concrete as a termite barrier are illustrated in Figure 7–3.