Pre-Treatments
How Termite Pre-Treatments can SAVE you MONEY:
Types of Pre-Treatments
There are three main types of construction recognised in South Africa with specific poisoning guidelines:
Poured Slab – This is for a building that sits flat on the ground, typically on a concrete slab. A termite technician will measure the area (usually from the plan) which is to be covered by the structure (with concrete, including masonry blocks and/or support columns, if applicable). Ideally, the termiticide will be applied to the sub-floor before any
concrete is poured. Most termiticide labels require the application of one gallon of dilute termiticide per 10 square feet of slab area (around 5 litres per sq m).
If the sub-slab soil is not poisoned prior to the concrete pouring, the slab is then drilled, following the label directions, adjacent to the foundation/ perimeter, support columns and other critical areas, and then the termiticide emulsion is pumped into the soil with a laterally-dispersing hollow rod. The label-specified volumes and concentrations vary across the brands, but usually require 2-4 gallons per 10 liner feet (about 2 to 5 litres per metre).
Crawlspace Foundations - A suspended floor (often timber) is built with a sub-floor air gap. In South Africa, this gap is typically tall enough to allow a technician to crawl beneath the floor, hence the term ‘crawl space’. Poisoning a crawlspace involves the placement of a of chemical to the soil so as to provide as close as possible (to a but never quite) continuous chemical barrier on both sides of the foundation. The outside perimeter of the foundation is treated at the footer level. The application rate is usually 4 gallons per 10 linear feet (about 5 litres per metre). If the foundation consist of hollow blocks, an additional 2 gallons per 10 linear feet is often required. Other structural elements of the building must also receive treatment in the soil surrounding them – support columns, porches, plumbing penetrations and other critical areas. This rather haphazard approach is much less certain than the highly detailed application specifications used in Australia’s Standard 3660.1
Basement Foundations Poisoning the soil around these structures is difficult, but much easier during construction than after. The termite pre-treat of a basement seeks to create a continuous chemical barrier on both sides of the foundation. The treatment guidelines are very close to the “crawlspace” requirements, but extra drilling of masonry
voids near the footer is usually done. Ideally, a basement would be made from void-free solid poured concrete and the termite entry points then reduced to just the joints (which can be blocked with a termite-resistant sealant. Trying to create a barrier in hollow masonry by drilling into it and flooding the voids is at best wishful thinking. The termiticides will not fully penetrate the mortar and many entry paths usually remain. Any exclusion of the termites is usually attributable to the termiticide placed around the exterior walls, however even here, the settling of loose fill can create voids through which termites can easily pass.
Is Termite Pre-treatment Worth The Cost?
Competently treated structures are expected to resist termites for a much longer period of time than untreated or post-construction treated structures. However, the treatments are not permanent—if they were they would not be allowed—so it is always preferable to rely on physical barriers as the primary protection. While some chemicals may be still adequately poisonous after 10 years under a slab, most will be significantly degraded and the pest managers typically suggest re-application to accessible areas by 5 years after construction. Some building features that are frequently tested by termites, such as where plumbing penetrates slabs and any buried masonry walls, are not accessible once construction is completed unless significant and damaging works are undertaken. The costs of poisoning at construction are typically 50-70 percent less than for a post-construction job, but more importantly it is only during construction that all the potential risk areas can be properly identified.
Termite Pre-treatments and New Additions/Structures
All new constructions in areas where subterranean termites are a risk should have barriers installed. New additions to your home, such as – garage and sunrooms – also require barriers to termites. Even if the home was poisoned before, termites can bypass the original termiticide and attack the new structure.
Swimming pools can be damaged by termites if the walls are made of wood that have not been rated for wood-to-ground contact. Termites will chew through most soft plastics, so swimming pool liners are readily damaged, particularly if they are placed directly over a food source such as peat. Modern plastic water pipes and tanks are similarly at risk but metal and unplasticised PVC pipes are rarely affected.
