Produced in British Columbia and Quebec, Canada, Copyright © 2019 Ecoshel, Inc., Boston, MA. All rights reserved. TM: Ecoshel, Smart-Shingle.
Capillary Breaks between shingles isolate moisture to the top layer, and prevent trapped water that can cause cupping and decay.
traps water between shingle layers.
Cupping occurs when the surface dries and shrinks while the back of the shingles are still wet.
Saturated, non-ventilated shingles require a long time to dry out.
Trapped moisture promotes decay.
Solar Vapor Drive problems occur when
shingles are tight against the sheathing.
Solar energy forces water vapor through the vapor permeable house wrap, into the wall where it can cause mold and decay.
Built-in Ventilated Rain-Screen
A slight gap between the shingles and the sheathing prevents solar vapor drive
by allowing water vapor
to vent to the exterior.
Specifying a ventilated rain-screen installation is an important decision. When siding is installed without ventilation, moisture "banked" in the siding can be vaporized and driven through the vapor permeable house wrap by solar energy. Solar vapor drive can work as a pump, moving moisture into the wall assembly where it accumulates and cannot dry out. This creates a permanently damp environment inside the wall that is ideal for mold and decay fungi.
This hidden decay often determines the lifespan of the structure. Unventilated installations can result in significant levels of decay in the sheathing and wall cavities in as little as 10 years. For this reason, some building departments now require "rain-screen" installations.
The Ecoshel Cedar Shingle System includes ventilation ridges on the back of the shingles that provide a slight gap between shingle layers, and between the shingles and the housewrap or underlayment. This built-in ventilation de-pressurizes solar vapor drive, providing an easier vapor path to the exterior.
As a true shingle system Ecoshel provides excellent protection in extreme weather, with the shingles functioning as multiple layers of drainage planes, each directing moisture back to the surface. Ecoshel is a highly weatherproof roofing installation, even when installed as siding, so the Ecoshel rain-screen space does not need to function as a drainage plane. The 0.10" rain-screen space works well to de-pressurize solar vapor drive.
A narrow rain-screen space simplifies construction, eliminating the need for door an window jamb extensions, as well as the need for screened vents at the base and top of the walls. A narrow space also minimizes the condensation potential, reducing the ventilation requirement. An Ecoshel installation is continuously ventilated throughout the entire surface, providing an installation that is both highly weatherproof, and well ventilated.
Ecoshel's built-in ventilation system also provides a capillary break between shingle layers, which helps isolate moisture to the top layer so the assembly dries much faster than three saturated layers of shingles. Faster drying helps prevent decay. The capillary break also works to prevent trapped moisture between shingle layers. This helps prevent cupping that occurs when the sun dries the surface of the shingle while the back is still wet.