Modified Bituminous Membrane Roofing
Use this CSI 3 part SimpleSpecs™ master specification to specify rigid roof insulation, modified bituminous roofing membrane, and related flashings.
Roofing is composed of multiple plies of roofing membrane that are applied using hot asphalt or cold adhesive, or by torch application. The top ply has mineral granules or aluminum foil to provide physical protection and prevent ultraviolet degradation.
Roofing membranes are either SBS (styrene butadiene styrene) or APP (atactic polypropylene) modified bitumen with an integral reinforcing mesh. They are often installed over a cover board to provide protection against hail and foot traffic and for enhanced fire protection.
The ability of a roof to withstand high winds and resulting wind uplift is directly affected by the roof systems construction and attachment. Organizations such as Factory Mutual (FM) and Underwriters Laboratories (UL) rate roof systems for wind resistance. While FM is an insurer and therefore places requirements on more than just the insulation attachment, their ratings can be used as a guide for the roofing system.
Roof insulation is available in many forms, the most common of which are included in this section.
The R-value of any insulation that uses a blowing agent, in this case polyisocyanurate and extruded polystyrene, decreases after the insulation is manufactured. Consequently, the R-value for this type of insulation is rated by LTTR – Long Term Thermal Resistance, typically measured 5 years after manufacture.
For assistance in selecting and detailing modified bituminous membrane roofing refer to the National Roofing Contractors Association (NRCA) Roofing Manual: Membrane Roof Systems, available from NRCA at www.nrca.net.
Related SimpleSpecs™ master specifications:
The SimpleSpecs™ master specs concept
Design professionals are accustomed to seeing lengthy project specifications, so why is SimpleSpecs™ so short?
Specifications have grown evermore wordy over the years for several reasons:
The mistaken belief that specifications must be lengthy and legal-sounding to be enforceable. In fact, quite the opposite is true. Having shorter, easily understood specifications makes us less likely to have problems in the field.
A belief that having lots of words protects us from a Contactor making mistakes. There is no way to include enough statements to protect yourself from a bad contractor, regardless of the length of your specification.
Our desire to be in control of the project by specifying means and methods instead of including simple, enforceable statements.
Easier to Edit
SimpleSpecs™ is written as a series of Microsoft word files that include statements that affect construction costs or overall quality and are far simpler to edit than other master specification systems.
Each SimpleSpecs™ specification section is non-proprietary and includes three manufacturers that meet the specified reference standards, descriptive, or performance-based requirements. They are written to allow any listed manufacturers to provide the specified products.
Hidden Guide Text
Each SimpleSpecs™ specification section includes hidden text to inform and guide users in editing the specifications to suit project conditions.
SimpleSpecs™ sections are edited using pre-defined options that are contained in [brackets] or by selecting optional text separated by "OR" statements. Paragraph and page numbering are included as automatic codes, eliminating the need to renumber when revisions are made manually. Global changes to headers, footer, terms, font colors and phrases are easily updated using a third-party search and replace software, available through ZeroDocs.com.