Three Difficult Systems Some recent building construction has made it difficult to properly inspect and treat for termite and moisture conditions. The pest control industry is currently working with building code officials to make these designs more accessible. Already, Dryvit has been modified for better moisture drainage and Encapsulation installs have been changed to allow for inspections at the top of the foundation. We are still working for more improved inspections and treatment procedures. Currently, Ewell Pest Control treats each of these designs on a case by case basis to be sure your home can be properly protected. The image at left shows what can happen hidden behind Dryvit if it is not properly maintained. Below, each design is discussed.
Click for larger view of a home with Dryvit
1.Dryvit Systems Dryvit systems were designed to make outside structural walls energy efficient, as well as making it visually appealing at the same time. Unfortunately, it was discovered that if moisture got behind the system through cracks around windows, doors, and other openings in the system, as well as from damage to the outer shell, it would become encapsulated between the foam and insulation and actually decay the plywood sheathing and studs from the inside. This would not only allow for severe structural damage, but termites would find this moisture and actually live in colonies above the ground within this "perfect" environment. Not only was this damage hidden between the drywall and Dryvit system, but treatment was impossible without further damage to the system from the chemical and additional drilling to get the chemical to the termites. After many years of litigation, the Dryvit system has been improved, but there are still limitations to inspections and treatments. The key to preventing moisture intrusion is to keep the entire system maintained by proper re-caulking with premium adhesive and promptly repairing damaged coatings. Preventing water leaks from above, within, and below, along with crawlspace ventilation, helps to control moisture and termite entry into Dryvit. We also use infra red cameras to better find moisture behind walls of these designs.
Click for larger view of crawlspace with sprayed-on foam
2.Sprayed Foam Systems Foam that is sprayed on wood for insulation is just as much of a problem as Dryvit systems if moisture were to enter through cracks in the foam. Inspections are also just as difficult. In addition, the foam is attached directly to the wood, masonry, wiring, and other attachments and allows termites and moisture to stay hidden unless the foam is removed. The weakness of damaged wood is masked because the foam can help support loads that the wood itself should be supporting. Termites can actually tunnel easily through the tiny voids of foam and be protected from moisture loss and temperature changes, eating wood throughout the colder winter and drier summers.
Click for a larger view of an encapsulated crawlspace
3.Crawlspace Encapsulation System Despite their name, these systems rarely encapsulate, or completely surround the entire crawlspace. However, just as with Dryvit and Spray Foam, they do cover critical areas where termites can enter. Also, the foam and/or vinyl cover is impermeable to moisture, so if water gets behind or under this cover, it will not dry out sufficiently. As an example, if you ever had an above ground pool or laid a tarp on the ground for an extended period of time, when it came time to remove these, it would always be wet where they set on the ground. The moisture gets trapped under the vinyl and has no where to go except on the substrate behind it. Masonry will wick up any water below it, adding additional moisture behind the vinyl. You can bet termites will find this moisture and get into the wooden understructure above!
Each of these 3 designs offer unique opportunities for termites to find moisture and enter homes from the crawlspace undetected. Treating for these invaders using conventional industry practices could damage these designs in certain situations. Ewell Pest Control's Certified Entomologist has prescribed various treating techniques to give you, the customer, our best effort to protect the home from termites while avoiding damage to these systems. This treatment, as well as limited inspections, means the customer must understand that there can still be unique termite and moisture conditions not covered under the usual termite warranties. Although most termite companies "walk away" from these cases, Ewell Pest Control meets these challenges, as well as any future designs, so that no home in Hampton Roads stays vulnerable to termite attack. With the homeowners cooperation to maintain these designs and to quickly repair any moisture leaks, it is still possible to provide protection.
