Unvented flat roof assembly.
Flat roof assembly.
Before constructing a flat roof assembly please refer to the unvented roof assembly comments under 6 2 vented and unvented roof assemblies and if applicable 6 3 parapet walls.
Flat roofs are nothing new nor are some of the proven materials that cover these often expansive roofs such as those found on factories warehouses big and small box stores apartment buildings large public structures and schools universities.
The main components typically remain constant while the only component that will vary is the roof membranes manufacturers roof system which is the waterproofing barrier or top layer of the roof assembly.
In unvented flat or low slope roofs with parapets perform a full flood test to ensure leak free installation of roofing membrane.
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.
For each different material multiply the thickness by the standard r value per inch for that material.
The roof felt asphalt tar layering is repeated in overlapping layers until the assembly is two to fours plies in thickness.
Conventional flat roof assembly.
To calculate the total r value of a roof assembly find the total thickness in inches of each type of insulating material within the system.
The international codes i codes are the widely accepted comprehensive set of model codes used in the us and abroad to help ensure the engineering of safe sustainable affordable and resilient structures.
Test roofing membranes for integrity prior to covering from below.
The components of a conventional flat roof assembly varies very little from roof to roof.
Sc historically typical construction of homes in canada and the us have vented attics between the ceiling of the interior space and the roof.
A flat roof s design is both efficient and economical.
However designers of compact roof assemblies must consider vapor permeance and arrangement of the roofing materials to produce acceptable hygrothermal performance and low.
The higher the interior moisture level the thicker the.
Roof assemblies must control for exterior moisture in a monolithic and complete fashion.
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.
Add the results for all the materials together to get the total r value for the roof assembly.
A wear surface of finely crushed stone granules is usually applied to the top layer of hot tar to protect the built up roof assembly from uv light and weather.
An unvented roof assembly is constructed without any ventilation and is fully sealed on all sides and filled with insulation.
