How Subterranean Termites Get Into Structures A Guide for Architects and Builders Dina Richman University of Florida

How Does the Problem Start? A.Existing Colony –Tubes connect colony to structure –Most frequently near moist wood and soil B.New Colony –King and queen choose area and excavate –Seek moist wood and soil Require Food, Water, and Access

Existing Colony: Mud Tubes Connect Colony in Soil with Wood in House

Typical Termite Entry Into Structures 1. Termites consume wood in ground 3. Finally infest wood 2. Then construct tunnels

Mud Tubes

Wood Next to or Under Structure Provides Food

Termites Access Into Structure Floating Slab

Termites Access Into Structure Partially Supported Slab

Termites Access Into Structure Supported Slab With Veneer

Termites Access Into Structure Monolithic Slab With Veneer

Crack in foundation Wood in contact with soil

Termites Access Into Structure Wooden Porch

Termites Access Into Structure Dirt-Filled Porch

Foundation Penetrations Concrete shrinkage allows termites access

Foraging and Guidelines Guidelines preferred When unconstrained, termites will tunnel in a radiating pattern When guidelines are introduced, the uniform tunneling pattern is disrupted and direction proceeds along guidelines

Foraging and Guidelines Day 14Day 14 (Found Gap 3d)

What Are Guidelines?

Construction Mistakes and Homeowner Alterations Allow Termite Access

Exterior Finish Below Grade Allows Termites Hidden Access

Hidden Termite Access Monolithic slab Vapor barrier used as form Brick veneer and stucco extending below ground

Hidden Termite Access

Subterranean Termite Entry Points Foundation –Cracks –Plumbing connections –Expansion joints –Utility conduits –Non-integral footers (Cold joints) Exterior Siding –Stucco –Brick veneer –Wood, vinyl, Hardy Board –EIFS

New Colony: What Makes an Area Attractive? Moisture Next to Foundation Gutters and downspouts Improper drainage, grading Sprinklers, irrigation, water spigots Roof leaks

Gutters New Building Code –Gutters and down spouts on eaves under 6” wide Water can build-up next to foundation due to lack of gutters

Mis-directed downspouts

Sprinkler head directs water towards bushes

Roof gravity

Improper Roof Flashing No flashing Not effective Allows moisture buildup In wall voids Adjacent to foundation

Walls Voids

Summary of Key Concepts Food –Wood-to-soil contact –Form boards not removed –Wooden debris left inside CMUs –Wood refuse buried under slab Water –Improper drainage, grading –Irrigation wets foundation Access –Exterior cladding, EIFS below grade –Landscaping –Plumbing penetrations –Additions, adjacent slabs

Why Pre-Construction Treatments Fail Pre-construction disruption –Additional grading, vapor barrier, walking across treated area Contractor error –Grade stakes, form boards, cellulose debris within foundation Post-construction disruption –Landscaping or add-ons Breakdown due to climate and soil conditions Applicator error

Infestation Rates in St. John’s County X 2 = , df = 2, P = 0.001

Author: Dina Richman, University of Florida Photos: Dina Richman and Cynthia Tucker, University of Florida Entomology And Nematology Department Copyright University of Florida 2000 For more detailed information see the Featured Creatures WWW site at