TimberHP's Wood Fiber Insulation - TimberBoard™, now Commercially Available Nationwide with recently published ICC-ES Evaluation Report

MADISON, Maine, Dec. 4, 2025 /PRNewswire/ -- TimberHP, Inc. announces a major milestone in the North American building materials' industry: TimberBoard™, the company's rigid wood fiber board insulation, has officially earned ICC-ES Evaluation Report ESR-5387, confirming compliance with the 2024, 2021, and 2018 International Building Code (IBC) and International Residential Code (IRC) for use as nonstructural continuous exterior insulation in Type V-B construction and IRC-governed dwellings.

This achievement completes TimberBoard's U.S. market launch, enabling TimberHP to sell and distribute its flagship rigid board insulation nationwide for residential, multifamily, and commercial projects.

"The ESR certification gives TimberBoard immediate legitimacy with code officials, architects, and builders across the country," said Matthew O'Malia, Co-Founder and CEO of TimberHP. "It signals that our carbon-storing wood fiber insulation meets the same code pathways that the industry already understands, removing friction for adoption and accelerating our ability to serve the market at scale."

ICC-ES is one of North America's most respected conformity assessment bodies, and its evaluation reports provide a trusted, standardized way for local building officials to verify compliance without conducting separate engineering reviews. With ESR-5387, TimberBoard is a fully recognized, code-supported solution, a shift that significantly reduces barriers for permitting, plan review, and specification.

The ICC-ES report validates TimberBoard's compliance across multiple performance categories, including thermal resistance, density, surface-burning characteristics, corrosion resistance, and moisture vapor sorption, confirming its suitability as durable, continuous exterior insulation. In practical terms, TimberBoard is produced in thicknesses from 1.5 to 4 inches and in standard 4-by-8-foot sheets, with a nominal density of 9 pounds per cubic foot, thermal resistance up to R-14 at 4 inches, and surface-burning characteristics of a flame-spread index of 75 or less and a smoke-developed index of 450 or less at 4 inches. 

These performance values support long-term durability behind a wide range of claddings and align with TimberHP's broader technical and climate zone guidance for compliant wall assemblies and permitted vapor retarder types in Climate Zones 3 through 8, giving architects, specifiers, and code officials clear, code-aligned criteria for design and approval.

TimberBoard, with commercial sales started December 1, is the first and only dry-process wood fiber insulation board manufactured in North America. By earning an ICC-ES evaluation report, TimberBoard now stands alongside legacy continuous insulation materials—allowing builders to choose a renewable, carbon-storing, vapor-open alternative without navigating complex alternative-material approvals.

About TimberHP

TimberHP manufactures high-performance, carbon-storing wood fiber insulation—TimberBoard, TimberBatt, and TimberFill—at its production facility in Madison, Maine. Designed for North American codes and installation practices, TimberHP products deliver superior thermal, acoustic, and moisture-management performance for residential, multifamily, and commercial buildings.

To learn more or download ESR-5387, visit www.timberhp.com/timberboard.

SOURCE TimberHP