What is a drawback of using rigid foam insulation board below grade?

Using rigid foam insulation board below grade can indeed allow termites to bypass soil treatment barriers. This is due to the fact that the insulation creates a direct pathway from the soil to the structure above, which can be particularly problematic in areas where termite treatments are applied to the soil, such as termiticides. When these barriers are compromised, it becomes easier for termites to gain access to the wood frame of a building without having to traverse the treated soil.

Understanding this characteristic is important for termite control strategies. In terms of physical design, rigid foam insulation does not provide a barrier to termites the same way a treated soil barrier does, making it essential for pest control professionals to consider the placement and use of such insulation materials in areas prone to termite activity. Proper assessment and integration of pest management practices are necessary to ensure that insulation materials do not inadvertently create new pathways for pests.