Unvented Flat Roof Insulation

An unvented assembly can perform well but it s important to get the details right to avoid sheathing rot.

Unvented flat roof insulation.

Basically the term cold roof refers to a traditional roof or vented roof while hot roof refers to a roof that is not ventilated and which has foam insulation attached directly to the roof sheathing. Yes unvented roof assemblies can be insulated with fiberglass a wufi post and not just in climate zones 2b amp. Controlling ice damming by keeping the roof cold. There are traditionally four main reasons for venting a roof.

Removing moisture from roof cavities structural members sheathing and insulation. The higher the interior moisture level the thicker the. Unvented roof systems where the insulation and air barrier are applied directly to the underside of the roof deck are common in applications where designers are seeking cost effective and energy efficient roof assemblies. The colder the climate the thicker the rigid insulation required.

Enhancing roofing material life span by reducing sheathing temperature. In this case you can learn a lot from foam tech s article vented vs. The quest for greater energy efficiency in buildings has led to increasing interest and need for insulation improvements in hvac equipment more airtight construction new materials and assemblies. Unvented roofs vented roof.

However designers of compact roof assemblies must consider vapor permeance and arrangement of the roofing materials to produce acceptable hygrothermal performance and low. Senior engineer manager at icynene john broniek makes the case for the unvented attic assembly and why insulating the underside of the roof makes sense. Condensing surface temperature controlled the thickness of the rigid insulation at both the roof deck and perimeter is determined by a calculation procedure similar to figure 5. Martin s post focuses on the marketing of owens corning 039 s propink unvented attic insulation system.

Unvented flat roofs a technical discussion flat roofs have often been built with the insulation all on top of the vapor closed drainage plane as this avoids dew point condensation issues inboard of the roofing. Unvented flat roof assembly. Unvented roofs which provides a detailed explanation of each. These assemblies are created by eliminating ventilation openings and moving the thermal moisture and air control boundaries to the plane of the roof deck.