The Accoya Siding Technical Information Guide (US PDF) provides detailed requirements for installing Accoya® siding as a fully ventilated rainscreen system. This document covers horizontal, vertical, and diagonal applications, furring layouts, fastener rules, machining guidelines, coatings, and fire performance. It is the master reference for designing and installing Accoya siding in North America.
Accoya must always be installed as part of a ventilated siding system. The guide outlines cavity-depth requirements based on annual rainfall—ranging from ¼” in dry climates to ½” or more in high-rainfall or coastal regions. Continuous airflow at both the top and bottom of the wall is essential, with screened openings to prevent insect or rodent intrusion. The manual recommends 2″ clearance above roofing and 6″ above grade, with gravel beds beneath siding in splash zones.
Horizontal siding guidelines include maximum furring spacing (24″ over sheathing or 16″ without), minimum furring dimensions (1½” × 1½”), and conditions where unsupported tongue-and-groove joints are allowed. Vertical and diagonal siding require double furring or additional ventilation strategies when only horizontal battens are used. All horizontal furring must be chamfered to shed water into the cavity.
Fastener rules specify stainless-steel nails or screws (304 or 316 grade), pre-drilling at board ends, minimum penetration depths, and maximum nail diameters. Galvanized, coated, or plated fasteners are not permitted. Nails or screws must never be overdriven, and staples or T-nails cannot be used.
Machining and handling guidelines cover proper storage, transport, cutting, planing, profiling, and limitations when producing thinner siding boards. The guide includes notes on sticker-mark removal, machining speeds, and how Accoya behaves when ripped or bent.
A full fire-behavior section outlines Accoya’s ASTM E84 Class C rating and details WUI (Wildland-Urban Interface) compliance with ASTM E2707. The siding assembly tested includes ¾” Accoya T&G over DensGlass with a ventilated cavity.
Coating recommendations include rounding edges, coating all four sides, end-grain sealing, breathable, UV-resistant coatings, and maintenance expectations.
Download the full Accoya Siding Technical Information & Installation Guidelines (US PDF) below for diagrams, furring details, fastener rules, machining tips, and WUI compliance notes. For help planning an Accoya siding system, your TimberTown team is always here to help.
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