Insulated Concrete Form Icf

Termite Protection

Termite protection is a growing issue with ICF construction below-grade in areas of heavy termite infestation. One major concern is the use of foam below grade because it provides a hidden pathway for termites into a structure. Commonly used termite barriers such as soil treatment and termite shields have reportedly been defeated in some cases. Some model code organizations have acted to limit the use of foam below grade in at least some areas particularly susceptible to termite infestation, namely the southern U.S. However, termite infestations can

and do occur in areas not normally considered prone to such infestations. This issue is potentially of concern even if all exterior walls are made of ICFs. Termites have been known to travel great distances within a structure to reach wood. This could mean wood used for window or door bucks, interior walls, roof systems, furring strips and the like are all susceptible to attack.

The 1997 Edition of the Standard Building Code (SBC), developed and maintained by Southern Building Code Congress International (SBCCI), prohibits the use of foam insulation below grade and within six inches above grade in heavily-termite infested areas. Even in areas determined to have heavy termite infestations, some ICF houses built on top of slabs and most conventional

CIP concrete or block walls used for crawlspace and basement walls should not be affected by this code requirement. The 1998 CABO code also prohibits the use of foam insulation below grade in areas prone to termite attack.

Even in the absence of code requirements, at least one manufacturer, and common sense, indicates that, in areas prone to termites, ICFs should not be used below-grade until effective solutions are determined.

The ICF industry reports that it is currently working to assess the extent of the problem and address it by evaluating solutions. The Insulating Concrete Forms Association (ICFA) recommends, and codes often require, that traditional termite control methods be used for any new construction.

Some foam is treated with boron to resist termite boring but this does not prevent them from traveling behind the foam. Chemical barriers are not always completely effective either as termites may enter the structure below the chemical barrier. The use of pressure treated wood, which is less attractive to termites, for blocking, furring, bucks, etc. may be advisable although use of typically wet pressure treated wood can bring its own problems of excessive shrinking and warping.

A somewhat experimental, but apparently effective, method of termite protection is the use of uniformly-sized, course-grained sand barriers. It appears that the individual grains are too large for termites to push out of the way but the inter-grain spaces are too small for them to get through. This method has reportedly been used successfully in Australia and Hawaii and some builders have used it in Texas and California.

Homeowners and builders may also find that pest control operators will not provide a warranty for houses with foam below grade (essentially refusing to treat). They may also experience difficulty in obtaining loans and possibly insurance as well especially if a treater will not provide a warranty "I'm building in NW Arkansas, considered . . . a heavy termite infestation area. I was all set and thrilled to use . . . ICFs in the construction of the slab of my new house but when I tried to get exterminators to give me a bid, . . . they wouldn’t touch it").

Another possible solution that some mention is to use one of the wood-cement composite forms. However, this approach may not prove effective as it is not the foam per-se that is the problem, but rather the presence of a hidden pathway into the structure. The use of PVC plastic, metal, cement board or any other material against the foundation would provide the same sort of pathway.