I have written extensively in past TERM blogs about termites and the damage they can do to structures. But why? Besides the fact that I am an entomologist, and bugs are just plain cool, I am part of a team at Polyguard that has worked for many years to bridge the building industry and the pest management industry.
Current building standards require the use of materials that keep air and moisture out of structures. Recent improvements on these building materials and their installation have made it possible to add termite and pest exclusion to the building envelope as well.
Subterranean termites cause an estimated $5 billion in damage to structures in the United States each year (source). Since termiticide pretreatments are not required in all states, that cost has the potential to increase.
Polyguard has manufactured building envelope materials for sealing out water, and for sealing in energy, since 1970. In the TERM Barrier System Division, we have upgraded these same building envelope materials to exclude pests, as well.
By not including pesticides in our products, but instead strengthening them and installing them in the structure, we have created a physical barrier. Physical barriers do not kill pests, like a pesticide or a trap would, but instead physically block pests from movement into a structure. Physical barriers are not a new concept, but recent advances in the use of building materials to effectively exclude pests have made it possible to add new dimensions to integrated pest management strategies.
Implementation of non-pesticide termite and pest barriers into the building envelope can put long-term pest control options into the hands of the architect, builder, and subsequent owner.
Think of Polyguard as an innovator and manufacturer of barriers – not just barriers against moisture and corrosion, but against contaminants like radioactive radon gas, methane, and insect pests. The solution to all of these building envelope offenders lies in the TERM Barrier System.
ENNIS, TX – Polyguard Products Inc. announced this week that 2017 marked its 25th consecutive year of top line sales growth for the company.
“This streak rivals any that I know in the business world,” President Shawn Eastham said. “This is a credit to our diversity, the quality of our manufacturing practices and, most importantly, the employee owners who take so much pride in the work they do every day.”
Polyguard’s streak began in 1992 and has withstood the financial ups and downs of the various markets Polyguard serves, including several nationwide recessions. The leadership in place at Polyguard credits this to several factors that make Polyguard a unique company, highlighted in the company tagline: Employee Owned. Innovation Based. Expect More.
“Employee owners, historically, take a greater sense of pride in what they do, more responsibility for the overall health of the company, and there’s a system of checks and balances that keeps everyone working for the good of the entire company,” CEO John Muncaster, who has been the head of the company since the mid-1980s.
As a result of these increased sales, Polyguard more than doubled its manufacturing capabilities by moving the majority of its manufacturing facility to Corsicana, Texas to keep up with demand.
Founded in 1953, Polyguard Products specializes in products which protect surfaces and structures from moisture, water, or other undesired substances. Polyguard is an industry leader in the production of self-adhesive protective coatings for engineering and construction.
# # #
If you would like more information about this topic, please contact Tre Bischof at 214-515-5000 or email at Tbischof@polyguardproducts.com.
Polyguard Products, Inc. has announced that its TERM® Barrier System has received an evaluation report as a Termite Physical Barrier from the International Code Council.
Polyguard’s TERM Barrier System joins Termimesh®* as the second Termite Physical Barrier evaluated by the ICC. TERM is a termite exclusion system built into the “building envelope”, and is the first building-wide, nonchemical pest exclusion system available to designers and builders for sustainable construction.
The TERM Barrier concept started at a November 1999 meeting with Texas A&M Urban Entomology scientists. The meeting discussed whether Polyguard building envelope materials, which have been used since 1970 to seal moisture and energy leaks, could be refined to also seal out termites, as well.
The 1999 meeting started an 18-year program of lab and field testing with Texas A&M and four other major southeastern U.S. entomology labs. The resulting TERM Barrier System, built in at the time of construction, uses upgraded sealants plus several new design details to add pest exclusion capability. TERM Barriers seal off entry points for subterranean termites, as well as entry points of most other pests around the structure.
There are several TERM components where installation by a Pest Management Professional is required or preferred. These are sealant barriers for plumbing or electrical penetration, combination barriers for bath traps and blockouts, sill barriers, and particle barriers at exposed building perimeters.
TERM Barriers enable the expansion of IPM within new construction. Sustainable construction standards now call for IPM. IPM, in turn calls for “Nonchemical pest preventive measures……designed into the structure…….”.
To meet requirements for the ICC’s AC-380 Termite Physical Barrier standard, TERM Barriers were field tested at four termite-infested sites against both Coptotermes formosanus and Reticulitermes flavipes, which are the most economically destructive termites in the United States. In these 5-year field trials, wood protected by TERM Barriers suffered no damage, while all exposed wood control samples were destroyed.
Polyguard Products is a 100 percent employee owned manufacturer of protective materials based in Ennis, Texas. Polyguard employee-owners have generated a constant stream of innovative products, resulting in 25 consecutive years of growth in sales revenue.
The International Code Council (ICC), based in Brea, California, is dedicated to developing model building codes which “Protect the health, safety, and welfare of people by creating safe buildings and communities”. ICC Codes have been adopted as the building code standard by most U.S. governmental jurisdictions, as well as by many countries worldwide.
# # #
If you would like more information about this topic, please contact Dr. Cassie Krejci, 940-577-1830, or firstname.lastname@example.org.
Polyguard Products, of Ennis, TX, has announced the issuance of ICC ES-3632, an International Code Council evaluation report titled TERM® Barrier System [link to ICC report]. The report evaluates the TERM System against ICC’s AC380 standard for Termite Physical Barrier Systems. [Link to ICC]
TERM Barriers create a fine-tuned building envelope system, incorporating non-chemical physical barriers which exclude termites, insects, and other pests. Since insects and pests almost all enter structures by penetrating the building envelope, TERM excludes them at entry points around the structure. TERM is an upgrade of existing envelope materials, so the cost of this sustainability improvement will generally be moderate.
TERM Barriers are based on 18 years of research and university testing. Polyguard has worked with Texas A&M University entomology scientists since 1999. In 2014, the University of Florida, Louisiana State University and the University of Georgia began working with Polyguard.
The ICC’s AC 380 acceptance criteria for Termite Physical Barrier Systems closely parallel the stringent requirements which state pest control regulators have for chemical termiticides. Successful field testing for five years at multiple sites, using unprotected controls, is required.
As a sustainability innovation, the TERM Barrier System relates to LEED in two ways:
1. LEED V4 standards call out the implementation of IPM (Integrated Pest Management). LEED credits are using wording such as:
“Nonchemical pest preventive measures, either designed into the structure or implemented as part of pest management activities.” (underlining by Polyguard)
Until now, the only physical pest barrier elements available for designing into the structure have treated specific spots around the building envelope. TERM Barriers give a new alternative – materials to exclude pests all around the envelope. Close to 100 percent exclusion can be attained with proper construction.
2. TERM Barrier Systems add a new dimension to the WELL Certification. A search of the WELL Building Standard v1 for “pest” shows 66 occurrences of “pest” or “pesticide”. This frequency speaks to the potential improvement in interior wellness which built-in pest exclusion will bring. With reduced pest entry, buildings with TERM Barriers will experience long-term minimization of the need for chemical treatments.
Other sustainability upgrades within the WELL goals include a reduction in pest related health problems and increased peace of mind (comfort) for occupants.
Polyguard Products is 100 percent owned by its employees. On Dec. 31, 2017, the company will celebrate 25 consecutive years of sales growth. In 2017, Polyguard expanded manufacturing capability to over 500,000 square feet at its Ennis, Texas and Corsicana, Texas facilities.
Polyguard has manufactured protective coatings for structures and infrastructure since 1952. The company’s first building envelope product, 650 Waterproofing Membrane, was introduced in 1970.
Polyguard Barrier Systems Division will be at Greenbuild booth #1061 Nov. 8–11 in Boston.
Hello and welcome to another week of the TERM® Barrier System blog series! This week we will be continuing our summer blog series, Building Out Bugs, by highlighting a way you can block pests from entering the home through the slab. As part of the TERM Barrier System, Polyguard has developed TERM Flooring Underlayment membranes specifically designed for long-term exclusion.
Over time, cracks in the slab can occur due to expansive soils and settling of the structure. These cracks can be minor at first, but eventually lead to major issues. One issue is pest intrusion. If you remember from last week’s blog, termites only need 1/55th of an inch to get through the slab and into the structure.
Crack in slab found below carpet in a structure with a noted termite infestation. Athens, GA.
Good engineering minimizes the movement of these structures over time, but one cannot eliminate the minuscule openings that occur over time. By including an elastomeric barrier above slab, you can maintain protection in the event that cracks do occur.
Large crack in slab found below carpet in a structure with a noted termite infestation. Athens, GA.
TERM Flooring Underlayment Barriers are unique in that they provide moisture vapor protection and pest exclusion above-slab. I put emphasis on above-slab because there are two advantages to the placement of this barrier:
With above-slab installation, you will know the product is there. This seems like a simple point, but if the product is intended for below-slab installation and the concrete is poured without it, there is not much that can be done. With above-slab installation, TERM Flooring Underlayment Barriers do not interfere with the concrete process and there is more flexibility when scheduling installation.
When TERM Flooring Underlayment Barriers are installed above-slab, you are able to see that it was done correctly. Again, this may seem like a simple point, but many below-slab products can shift and become less effective when the concrete slab is poured. After installation of the TERM Flooring Underlayment Barriers, you can walk around the structure and do a thorough inspection before moving on, which provides peace of mind that the product will perform as intended.
There are four separate TERM Flooring Underlayment Barrier products that I will write about today. Each of these are elastomeric, fully-adhered membranes that are installed once the structure is dried-in. If you refer back to the blog about TERM Sill Plate Barriers, you will remember that we left a 1 inch overhang of the TERM Sill Plate Barrier on the interior of the structure. During the installation of the TERM Flooring Underlayment Barriers, you will tie in the membranes by overlapping and sealing the products together. This creates a complete horizontal barrier to vapor and pests above the slab. What a great concept, right?
The following barriers have been designed by Polyguard’s TERM Barrier System for use under tile and wood flooring materials:
TERM® Wood Floor Underlayment Barrierfor concrete substratesis a composite membrane of polyethylene backing and TERM® Sealant Barrier, 40 mils in thickness with a ½” extended edge to provide a complete overlap seal at the edge. This elastomeric, self-adhesive barrier is wound on cores with a disposable silicone coated release sheet which is removed immediately prior to application.
TERM® Wood Floor Underlayment Barrier for wood substrates is a composite membrane of polyethylene backing and TERM® Sealant Barrier, 40 mils in thickness with a ½” extended edge to provide a complete overlap seal at the edge. This elastomeric barrier is a loose-laid moisture barrier.
TERM® Tile Floor Underlayment Barrier is a composite membrane of fabric and TERM® Sealant Barrier, 60 mils in thickness. This elastomeric, self-adhesive barrier is wound on cores with a disposable silicone coated release sheet. Specified Polyguard primer is required for use. TERM® Tile Floor Underlayment Barrier fills the traditional role of anti-fracture tile underlayment, helping to prevent cracks in the subfloor from appearing in the tile surface above by absorbing stress created by the crack. Additionally, TERM Tile Underlayment Barrier has sound absorbing and insulating qualities making the floor quieter and warmer in winter.
TERM® Tile Floor Underlayment Barrier installed in The New American Home – 2017, built by NAHB in Orlando, FL
TERM® Flooring Underlayment Barrier for Crack Repair serves as a protective solution for cracks in the concrete slab. As cracks in the slab are discovered during the remodel process, 12” wide strips of TERM® Flooring Underlayment Barrier for Crack Repair may be installed over the crack as a barrier to subterranean termites. TERM® Flooring Underlayment Barrier for Crack Repair can be used in remodeling in strip form to prevent termites and moisture from accessing structures through cracks and non-moving joints in the slab.
It’s important to note that the TERM® Flooring Underlayment Barriers are intended for new construction, with limited use in existing construction. TERM Flooring Underlayment Barriers are a component of the pesticide-free TERM Barrier System which, when properly installed as part of the building envelope, acts as a barrier to almost all pests. Because almost all pests are excluded for the life of the structure, the need for pesticide treatment should be permanently and drastically reduced.
Hello and welcome to another week of the TERM® Barrier System blog series! This week we will be continuing our summer blog series, Building Out Bugs, by highlighting a way you can block pests from entering the home through weep holes. As part of the TERM Barrier System, Polyguard has developed the TERM Weep and Vent Barrier specifically designed for long-term exclusion.
Weep holes are openings on the structure’s exterior left between bricks by the mason. This small opening allows moisture to drain from the structure and for air to circulate. The problem with this necessary opening is that termites and other pests such as scorpions, ants, and small rodents can utilize the weep hole to gain access to the structure.
Termites attempting to exit a home from the weep hole after their mud tube had been removed.
When utilizing screen to exclude termites and other pests, it is important to consider screen size. The following table shows the screen aperture sizes that are required to exclude common pests.
As you can see, screen with openings of 1/55th of an inch or smaller are required to exclude subterranean termites. To develop the TERM Weep and Vent Barrier, we wanted to use a material that blocked the most pests while still allowing the structure to drain and vent. An example of this specifically-sized screen material, called TERM Micromesh®, is shown below with a subterranean termite.
The TERM Weep and Vent Barrier is a non-structural pest barrier which, when properly constructed as part of a masonry wall, will exclude pests of all sizes from passage. Polyguard’s TERM Weep and Vent Barrier incorporates a stainless-steel, corrosion-resistant screen and is unique in its ability to exclude both very small and larger pests. The very small mesh openings have been proven to block even the smallest termites found in North America. The strength of the stainless-steel mesh and the strength of the melt bond between the screen and the frame will resist every pest from the smallest termites to larger pests such as rodents, snakes, and scorpions.
The TERM Weep and Vent Barrier uses a 3/8” x 1 ½” x 4” rectangular PETG plastic frame, a stainless-steel mesh screen with 0.017” openings which is melt bonded to the plastic frame.
Weep holes are often left unsecured which, of course, offers no protection against foraging pests. Corrugated plastics and steel wool pieces are also used to deter pests. While this may work short term, it is not a permanent solution. Corrugated plastic leaves spaces large enough for small insects, like termites, or determined insects, like roaches, to pass through the weep. Steel wool needs to be recharged, as rodents will pull the material from the weep hole to gain access, or to use the steel wool in nests.
It’s important to note that the TERM® Weep and Vent Barriers are intended for new construction. TERM Weep and Vent Barriers are a component of the pesticide-free TERM Barrier System which, when properly installed as part of the building envelope, acts as a barrier to almost all pests. Because almost all pests are excluded for the life of the structure, the need for pesticide treatment should be permanently and drastically reduced.
Hello and welcome to another week of the TERM® Barrier System blog series! This week we will be continuing our summer blog series titled Building Out Bugs by highlighting a way you can block pests from entering the home through the horizontal isolation joints. As part of the TERM Barrier System, Polyguard has developed an isolation joint product specifically for exclusion in this difficult area.
Author, Cassie Krejci, Ph.D.
Isolation joints are generally formed with materials such as junk board, fiberboard, or foam, among others. These materials have worked well for the intended purpose, but when considering termite and pest exclusion, they are ineffective. Termites can utilize isolation joints to access a structure. As we all know, damage from alate termites (swarmers) or foraging termites can be expensive.
TERM Isolation Joint Barrier is a “peel and stick” termite barrier composite used for sealing isolation joints before pour of a new slab which butts against an interior slab. The TERM Isolation Joint Barrier is a non-structural barrier which, when properly constructed as part of the building envelope, acts as a barrier to termites entering the structure through isolation joints.
The TERM Isolation Joint Barrier is easy to install. The follow is an example of how the TERM Isolation Joint Barrier would be installed on the face of slab located at the garage where the future driveway would be poured.
First, the surface is cleaned with a wire brush and primer is applied to the concrete. The TERM Isolation Joint Material is then pressed into place against the concrete.
Use a roller to ensure contact with the vertical concrete surface.
When the new concrete is ready to be poured, simply unfold the micro mesh component from the TERM Isolation Joint Barrier at a 45° angle and peel off the release liner. Newly-poured concrete will bond to the isolation joint material and the micro-mesh will be embedded into the concrete.
This innovative new product will prevent termites from gaining access through this isolation joint.
The TERM Isolation Joint Barrier consists of a laminated elastomeric membrane which has a TERM Sealant Barrier adhesive on both sides. Total thickness of the TERM Isolation Joint Barrier is a nominal 0.5” (12.7 cm). The exposed adhesive faces of TERM Isolation Joint Barrier are covered by a disposable treated release sheet, which can be peeled away to expose the adhesive face. Roll width is 2” (.102 cm). Length is 25’’ (2.44 m). Embedded within the TERM Isolation Joint Barrier is a 4” wide stainless steel screen, with aperture opening of 0.018” (0.465 mm). Polyguard 650 LT Liquid Adhesive is required for installation.
It’s important to note that the TERM® Isolation Joint Barriers are intended for new construction.
TERM Isolation Joint Barriers are a component of the pesticide-free TERM Barrier System which, when properly installed as part of the building envelope, acts as a barrier to almost all pests. Because almost all pests are excluded for the life of the structure, the need for pesticide treatment should be permanently and drastically reduced.
Hello and welcome to another week of the TERM® blog series! This week we will be continuing our summer blog series titled Building Out Bugs by highlighting a way you can block pests on the vertical surfaces of a home or structure by using TERM® Flashing Barriers.
Author, Cassie Krejci, Ph.D.
In the past, we have focused on how TERM® materials form a horizontal barrier throughout the structure. The horizontal protection arises from a collection of products that work together to block out insects, including:
TERM Base Flashing Barrier is, like our other membranes, a “peel and stick” barrier membrane used where waterproofing, energy sealing, and insect exclusion is needed. TERM Base Flashing Barrier is applied where the horizontal concrete slab intersects with exterior sheathing. This area is a frequent entry point for termites which have come up on the outside of the foundation wall. Additionally, the TERM Base Flashing Barrier ties in to the previously-applied TERM Sill Plate Barrier (see our last blog).
The TERM Sill plate barrier extends past the sheathing board by 2 inches, allowing the TERM Base Flashing to form a strong connection and protecting the structure from termite intrusion.
The yellow circle highlight the connection between the TERM Base Flashing and Sill Plate Barrier. Together, they form a strong connection and protecting the structure from termite intrusion.
The picture below shows what the TERM® Sill Plate Barrier looks like when installed and the structure has been dried-in. While the sills are protected from beneath, there is still visible light coming into the structure from the exterior. Don’t worry! With the TERM® Base Flashing Barrier, that light will not be visible in the finished structure. Energy will stay in the home, and air and insects will stay out.
TERM Seam and Window Barrier is also a fully-adhered, peel and stick, non-chemical barrier membrane applied over sheathing joints, and as a window flashing where both waterproofing and termite exclusion is desired. Sheathing joints are potential entry points for termites which have accessed the exterior wall via the exterior foundation wall, and climbing over the TERM Flashing Barrier installed at the base of exterior sheathing. Windows are a frequent entry point of both climbing and swarming termites.
TERM Flashing Barrier for exterior sheathing joints is tied in to the TERM Base Flashing Barrier. This connection continues the vertical pest barrier.
Without the proper barriers in place, damage by termites to your home or structure could be catastrophic.
Alate termites entering a structure through an exterior sheathing joint.
Termite damage to an unprotected door frame.
TERM Flashing Barrier and TERM Seam and Window Barrier are made of the same material. The only difference is in roll widths: TERM Seam and Window Barrier is available in widths between 4” and 8”, and TERM Flashing Barrier is available in widths between 12” and 48”.
It’s important to note that the TERM® Flashing Barriers are intended for new construction.
Check us out next week for the next blog of the series, Building Out Bugs: Isolation Joints where we will talk about our innovated isolation joint product.
TERM Flashing Barriers are a component of the pesticide-free TERM Barrier System which, when properly installed as part of the building envelope, acts as a barrier to almost all pests. Because almost all pests are excluded for the life of the structure, the need for pesticide treatment should be permanently and drastically reduced.
We know that humans have been competing with insects for millions of years as indicated by fossils, fables and forensic science. Early humans adapted to using layers of clothing and setting up indoor living accommodations, or caves, to protect themselves and their possessions from insects. These principles of human harborage have evolved into the free-standing structures we know today, but the hope of building out insects is still present. According to the United States Department of Agriculture, we compete daily with insects for food, fiber and forestry products. In our homes, termites are one of the more prevalent threats. Advances in the use of physical pest barriers to effectively exclude subterranean termites have made it possible to add new dimensions to integrated pest management (IPM) strategies for both pre-construction and post-construction implementations. For more than 20 years we have been evaluating physical and chemical barriers against termites and other structural and household pests. Products such as particulate barrier systems have applications on the exterior of structures, and in and around interior plumbing penetrations. Sealants, membranes and wire meshes can be used as effective barriers to invading insect populations at the soil, concrete slab, veneer interfaces, as well as soffit and roof areas. Development of elastomeric membranes and advances in their use provides opportunities for pest management professionals to effectively solve problems with cracked slabs, cold joints and other construction abnormalities, which in the past have resulted in the incursion of pest populations. Sustainable building practice is the use of environmentally responsible processes that are resource-efficient. These are not new concepts, but hold a great deal of promise in ensuring the building is efficient during design and construction, as well as in operation and maintenance for the life of the structure.
Figure 1. Trench installation of particle barrier.
It is known that there are several requisites for life that are required for animals, such as insects, to survive. Heterotrophs must harvest food for energy and growth and have access to oxygen to be successful. Additionally, water, a favorable environment that provides the appropriate temperature and humidity, shelter from elements, and others of the same species to advance the population are required for success of an organism. To effectively control a pest population, reducing or eliminating access to any of these conducive conditions is key. Use of sustainable building practices in an IPM program results in effective pest exclusion with long-term efficacy. Building materials used in this type of control are environmentally sound and generally require little maintenance.
An Aggregate Barrier
One material that is at the forefront of pest exclusion, without the use of pesticides, is an aggregate barrier. These also are referred to as particulate termite barriers and are made up of specifically-sized aggregate. Particulate termite barriers have been widely and successfully used in other parts of the world since the 1980s. However, they have never been commercially available in the mainland United States. The principle behind particle barriers has been well researched by Ebeling and Pence (1957)1, Su et al. (1991)2, Su and Scheffrahn (1992)3, Yates et al. (2003)5 and Keefer et al. (2013)4. Research with particle barriers for the mainland United States was initiated at Texas A&M University in 2003 at the request of a Texas pest control professional. Various particle characteristics were evaluated, including size, angularity and interstitial space between particles. Results showed that a particle blend of aggregate sieve sizes 8, 10 and 12, as well as a mean angularity of 3200+ and 40% interstitial space, was most effective against tunneling subterranean termites4. This material is generally installed in a wedge formation that measures 4 inches across and 5 inches down, directly against the foundation.
Particle barriers were initially installed in 15 homes in South Texas in 2005. Each of the homes were infested with subterranean termites prior to the start of the experiment. Homes in this study were monitored for 10 years and the pest control professional monitoring reported no occurrences of termites during this field evaluation. Particle barriers were then reduced to practice in seven Texas homes in 2015. Each structure was initially infested with termites, but to date, none have shown evidence that termites have breached the particle barrier. Aggregate barriers have also shown success when installed in bath traps or slab leave-outs. During construction and after the foundation is poured, cardboard and other debris is removed from bath trap areas and the particle barrier is installed. Application of this material protects the structure from termite intrusion in these vulnerable areas. Implementation of particle barriers has expanded across the United States and serves as a reliable supplementation to termiticide use around new and existing structures.
Figure 2. Wood samples wrapped in membrane remained undamaged by termites for the five-year experiment, while unprotected wood was completely destroyed.
A Membrane Barrier
Another new material that can broaden the scope of service for pest control professionals is a membrane barrier. Membrane barriers are elastomeric, meaning they move when the structure moves without tearing, and are available in a caulk tube or adhered to a high-strength backing. Texas A&M University began testing on sealant barriers in February 2000 and continues to help improve them to this day. A field study was initiated in 2003 to evaluate the effectiveness of these elastomeric membrane barriers to protect wood against termite damage. Aged Southern Yellow Pine (SYP) boards were cut into billets. The treatment billets were completely covered and sealed with membrane barrier, which is self-adhering, while the untreated control billets were not covered with treatment materials. Sets of treated and untreated control billets were buried together in five different Texas locations with demonstrated subterranean termite activity. A total of 10 billets, 5 treated and 5 untreated controls, were buried on the same date and location. The protocol called for exhuming and removing one each of the treated and untreated billets, from each site on or about the annual anniversary date. The test units were to be taken back to the laboratory, carefully washed to remove soil and termite mud tubes, air dried, and then the amount of damage done to them by termites or other factors was estimated. Each of the extracted billets were visually inspected and the damage was rated using the ASTM scales (D3345-08), in which a rating of 10.0 meant “no damage” was observed, while a rating of 0.0 indicates the wood sample was “destroyed.”
Four samples of wood that were left untreated were completely destroyed by year 2 and the fifth sample was destroyed by year 5. Alternatively, samples that were wrapped in membrane barrier were rated at a 10.0, or undamaged, throughout the five-year field experiment. Membrane barriers are adhered to high-strength backings and are used to protect the below grade foundation. This material also operates as the waterproofing or vapor barrier, covers 100% of horizontal surface (penetrations, joints, and future cracks) above the slab, and seals all vertical seams, crevices and cracks. Additionally, membrane barriers have been adapted into a caulk sealant formulation that can be used to protect vulnerable intersections between pipe penetrations and the foundation that can be avenues for termite intrusion. When caulked around the plumbing penetration, sealant barriers adhere to the pipe (PVC, copper or others), and to the concrete. As the structure moves during settling or due to expansive soils, the sealant barrier material maintains a barrier that is impenetrable by termites and other urban pests.
Figure 3. Membrane barrier designed for termite exclusion is installed on a below-grade concrete foundation in Hawaii.
Screen Them Out
Screens with apertures small enough to block termites were developed in Australia and have been widely used in the United States, mostly for plumbing penetrations, since the 1990s. One of the early uses of screens for pest exclusion was the implementation of screen doors and window coverings in the 1860s. Screen used to mill grain were repurposed to cover windows to keep pathogen vectors, such as mosquitos, from entering homes.
Today, building codes require insect screens at vent openings, but entomologists know that smaller ones are often needed. Most insects can be excluded with screens measuring 1/16 inch (1.59 millimeter) in aperture size, but to effectively exclude termites, required screen apertures measure 1/55 inch (0.46 millimeter). Application areas for screens in the building envelope include weep holes, soffits, gable and ridge vents, among others.
The building envelope is a physical barrier between the interior and exterior of a structure that has been proven to keep energy in and environmental elements out. Each of these materials are upgrades to the building envelope that have shown to keep termites and other pests out. The goal of these types of materials is to build out pests with sustainable systems and exclude pests for the life of the structure. Each of the pest exclusion materials discussed herein are free of pesticides and are classified as “devices” or barriers by regulators.
Integrated pest management tactics employ the use of physical and mechanical barriers to control pests, along with chemical, biological and cultural, or sanitation, methods. In addition, federal and state governments emphasize sustainable systems as part of sound and effective IPM programs. An example of such initiative would be NPMA’s QualityPro Certification Program, a service option and certification developed by the National Pest Management Association that is awarded to companies that provide service options that are least-risk to people, property and the environment.
Figure 4. Membrane barrier may be installed as part of a bath trap barrier, along with screen and particle barrier, to exclude termites and other pests at concrete leave-outs.
Our goal as pest control professionals is to protect the health and property of our clients. We know that pesticides are effective for months to years, but buildings are built to last for decades. Termiticides are often reapplied during the life of the structure to protect against foraging termites. It’s important, as an urban pest management professional, to explore the use of proven non-chemical approaches such as mechanical and physical barriers to supplement pesticide use.
Sustainable approaches to IPM are part of the future for professional pest management. Through the use of aggregate barriers, elastomeric sealants and screens, we can solve difficult problems with pest incursions. Sustainable technologies such as these are excellent opportunities for add-on services. Resistance to chemical-only approaches and early adoption of physical barriers can put a pest control company ahead of the curve.
1Ebeling, W.J. and R.J. Pence. 1957. Relation of particle size to the penetration of subterranean termites through barriers of sand and cinders. J. Econ. Entomol. 50: 690-692.
2Su, N.-Y., R.H. Scheffrahn, and P.M. Ban. 1991. Uniform size particle barrier: a physical exclusion device against subterranean termites (Isoptera: Rhinotermitidae). J. Econ. Entomol. 84: 912-916.
3Su, N.-Y. and R.H. Scheffrahn. 1992. Penetration of sized-particle barriers by field populations of subterranean termites (Isoptera: Rhinotermitidae). J. Econ. Entomol. 85: 2275-2278.
4T. Chris Keefer, Dan G. Zollinger, and Roger E. Gold. 2013. Evaluation of aggregate particles as a physical barrier to prevent subterranean termite incursion into structures. Southwest. Entomol. 38: 447–464.
5Yates, J.R., J.K. Grace, and J.N. Reinhardt. 2003. Installation guidelines for the Basaltic Termite Barrier: a particle barrier to Formosan subterranean termites (Summary). Sociobiology 41: 113-114.
Krejci is lead research & technical sales associate for Polyguard Products’ TERM Barrier Division. Gold is former professor and endowed chair for Urban and Structural Entomology at Texas A&M University.
continuing our summer blog series titled Building Out Bugs by highlighting a way you can block pests on the horizontal surface, starting with TERM® Sill Plate Barriers.
TERM® Barriers are a collection of products that work together to complete the building envelope and block out insects. There are several products that complete the horizontal barrier for a slab-on-grade structure, including:
TERM® Sill Plate Barrier is an adhesive membrane barrier designed to prevent termites from accessing wood framing members from a concrete crack or joint in the floor. TERM® Sill Plate Barrier adheres to the subfloor and blocks termite access to the sill plate. The Sill Plate Barrier may be installed under exterior and interior sill plates.
Concrete cracks and joints are one of the main access points for subterranean termites into structures. A TERM® Sill Plate Barrier installed underneath the sill plate provides 5 advantages:
TERM® Sill Plate Barrier is a non-chemical barrier to subterranean termites. The barrier has been tested against termites since 2000 by Texas A&M University and is classified as a non-pesticide “barrier” by EPA regulators.
TERM® Sill Plate Barrier provides a full waterproofing and vapor proofing barrier for wood framing against moisture from the concrete.
TERM® Sill Plate Barrier blocks moisture and cold air from the exterior, and energy leaks from the interior.
TERM® Sill Plate Barrier excludes foraging insects, such as termites and ants, from entering at gaps between the sill plate and the not-quite-level slab.
TERM® Sill Plate Barrier provides supplemental protection to sodium borate treatment of wood framing.
Installation of the TERM® Sill Plate Barrier is simple.
For interior sill plates, it is ideal for the membrane barrier to overhang each side of the sill plate by 1”. This is recommended so that the sill plate barrier will tie-in to the flooring underlayment membrane, which we will discuss in the next blog post.
For exterior sill plates, it is recommended that the membrane barrier be 3” wider than the sill plate itself. This is to tie TERM® Sill Plate Barriers in to the TERM® Flooring Underlayment membrane on the inside of the structure, and the TERM® Base Flashing membrane on the outside.
Once all sill plates have been protected with the TERM® Sill Plate Barrier, any posts or penetrations and that fall within the area should be sealed with TERM® Sealant Barrier.
It’s important to note that TERM® Sill Plate Barriers are intended for new construction.
The following is what TERM® Sill Plate Barriers looks like when installed and the structure has been dried-in. While the sills are protected from beneath, there is still visible light coming into the structure from the exterior. Don’t worry! With the TERM Barrier System, that light will not be visible in the finished structure, thanks to the TERM® Base Flashing Barrier. Energy will stay in the home, and air and insects will stay out.
Check us out in two weeks for the next blog of the series, Building Out Bugs: Windows & Sheathing where we will talk about all the flashings that can keep bugs out and energy in.
TERM® Sill Plate Barriers are a component of the pesticide-free TERM Barrier System which, when properly installed as part of the building envelope, acts as a barrier to almost all pests. Because almost all pests are excluded for the life of the structure, the need for pesticide treatment should be permanently and drastically reduced.