Entry Points in Foundations

• Raised foundations that are within proximity of subterranean termite nests are commonly infested. Unlike any other insect, these termites build unique "mud tubes" to travel safely across open spaces, and the tubes are used to climb support piers and foundation walls to tunnel into wood and weaken structural members. Hollow block foundations provide open access to termite infestations from below as well through the cavities in the blocks. Slab foundations are invaded through cracks that appear from soil movement and along plumbing and electrical conduits that enter the slab.
  
  

Other Access Points

• Wood contact with soil is another way that termites gain entry to a structure. Wood siding materials, wall plates, earth-filled porches and decking members that are allowed to come into contact with dirt provide easy access to termite infestations. Landscaping is another common problem, especially when planters are installed against the building. Even shrubbery and trees close to the foundation provide entry for termites, as the roots are used as avenues of penetration.
  
  

Pre-Treatment of Foundations

• Foundation footings and walls are treated by mixing termiticide and water dilutions with fill dirt, and placing the mixture in trenches around footings and walls at a rate of four gallons per 10 linear feet. Concrete slabs are treated by applying termiticide on the sub-soil expanse before the slab is poured. This application is performed by using professional spraying equipment that includes a reservoir tank (usually 50-gallon capacity) and hand-held wands or sprayers. Termite contracting companies generally are hired to do these applications.
  
  

Post-Construction Treatment

• The method used for treating termite infestations occurring after a structure is completed depends on the type of foundation. Slab floors require using a hammer drill with a long bit (usually 10 to 12 inches) to penetrate the foundation, generally at intervals of four to six inches along the walls and in isolated sites of infestations. Raised foundations are treated with trenching similar to pre-treatment methods. Trenches are used around the exterior as well. In general, trenches are two to six inches wide and a minimum of four inches deep.
  
  

Non-Chemical Prevention Techniques

• Grading soil away from the foundation at a five-percent rate helps to prevent moisture from collecting around the exterior, which is an attraction for termites of all kinds. Breaking any earth-to-wood contact on wood siding or decking also reduces termite infestations. Plastic vapor barriers are often used in crawl spaces beneath structures to control moisture, and removing food sources such as cellulose debris (scrap wood, cardboard, paper) from these areas is also recommended.