Thermally Modified VikingWoodTM Featured in Façade of Prestigious School in Hawaii

Date: October, 2019

A new residence hall graces the campus of ‘Iolani School in Honolulu, Hawaii as part of a larger, multi-year expansion project for the culturally diverse, co-educational preparatory school that serves more than 2,000 students. VikingWoodTM, a natural, green, chemical-free thermally modified wood, manufactured by AHC Hardwood Group, based in Atlanta, Georgia, can be seen accenting the exterior of the five-story structure.

The residence hall was designed by G70 (formerly Group 70 International, Inc.) a Honolulu-based award-winning architecture, civil engineering, interior design, planning and environmental firm. According to Lance Hirai, AIA, G70 project architect, “Responding to the surrounding context, the architecture honors the original housing and style that occupied the site, but with a contemporary expression.”

HK Consultants, LLC of Aiea, Hawaii, suggested the cost-effective, sustainable, high-performance exotic wood alternative, often used for exterior applications. According to Mark Hee, exotic wood specialist and senior partner at HK Consultants, “When you have a lot of moisture in the air, a wood that is not kiln-dried properly is going to absorb moisture, and with moisture you get mold and mildew. This lets us take a wood that is normally very inexpensive that is treated through the thermal modification process to create a wood that can compete against more expensive exotic woods like ipe.”

Hirai explains how VikingWood thermally modified ash came to be specified for the residence hall exterior, “We were inspired by biophilia1 due to its benefits in enhancing student development. Connections to nature are reinforced through the use of natural materials like the thermally modified wood panels. We were keen on using natural materials to also maintain an honest expression of the architecture, as well as add warmth to the exterior, and with time, the wood will weather and serve as an example of how a building can age.”

A number of different exteriors were considered for the exterior facade of the residence hall, including composite materials. Several desirable characteristics of thermally modified VikingWood wood weighed into the decision, including the green, chemical-free nature of the wood.

VikingWood also acquires a rich, brown color during the thermal modification process and was finished with a clear WOCA exterior stain. According to Hirai, “We wanted to truly reflect the color of the thermally modified wood.” A clear stain was applied to experience the natural graying process, rather than a colored stain or a UV coating to inhibit the graying effect.

VikingWood is treated under extremely high temperatures (400oF+), which cook away the natural sugars found in wood, leaving a safe, green alternative to chemically preserved wood. Under this extreme heat, the hardwood is “thermally modified,” permanently altering the wood’s chemical and physical properties. The thermal modification process reduces the equilibrium wood moisture content down to a very low range of 5 to 6%. The thermally modified ash used for the ‘Iolani residence hall offers a Class 1 exterior durability rating.

Once sugars are removed from the wood and the moisture content is reduced, the conditions that can lead to decay and rot, as well as attract bugs, are virtually eliminated. This process produces a wood that is up to 85% more stable than traditional kiln-dried woods. Thermal modification also virtually eliminates the ability for the wood to reabsorb moisture from the atmosphere, which can be an important consideration when building in high humidity climates.

Hee adds, “It makes a lot of sense that this wood can hold up to the elements and the pests. It’s a natural, green alternative to composites and doesn’t gray out like exotics, even in the tremendous sun we have in Hawaii.”

Hirai summarizes, “The dormitory moves forward the school’s vision to ‘Create meaningful, sustainable, and reciprocal global relationships that stimulate the exchange of ideas, foster a deeper cultural awareness, and build students’ desire to improve the world around them’.”

‘Iolani School was originally founded in 1863 by King Kamehameha IV and Queen Emma as a boarding school that housed students from around the world. The new dormitory can accommodate 112 students in grades nine through 12 and marks the first time since 1959 that on-campus housing has been available for students. The last phase of expansion on the ‘Iolani campus is slated for completion by mid-2020.

1. biophilia (n) bio·phil·ia: a hypothetical human tendency to interact of be closely associated with other forms of life in nature. Merriam Webster Dictionary