Significance and Use
It is important to evaluate the corrosion resistance of ferrous metal components used in low-slope roofing and waterproofing because they provide integrity and securement of other system components, such as insulation and membranes. Corrosion of ferrous metal components may result in their early deterioration and may lead to roofing or waterproofing system failure.
Results from testing ferrous metal components in an acidic atmosphere serve as an indication of the relative corrosion resistance of such components, coated or uncoated, to the environment of the test chamber. The results are not to be construed as a general guideline to the corrosion resistance of such components in other environments or in usage that may be conducive to corrosion.
Moist air containing sulfur dioxide quickly produces easily visible corrosion on many ferrous metals. It is therefore a test medium suited to detect pores or other sources of weakness in protective barrier coatings.
This test method applies primarily to evaluating the effectiveness of barrier coatings to provide general corrosion protection under test conditions. It is not intended to evaluate the resistance of the components to specific corrosion mechanisms such as crevice, galvanic, or stress corrosion.
This test method does not address abrasion resistance of barrier coatings when the fasteners are driven through above roof deck components, such as an existing built-up roof or insulations, or both.
Only the above deck portion of fasteners subjected to this test method is evaluated.
1.1 This test method covers components of ferrous metal fastener assemblies, excluding those of stainless steel, such as fasteners, stress plates, and batten bars used in low slope roofing and waterproofing, to a sulfurous acid environment. This test method evaluates relative corrosion resistance of the components by determination of percentage of rust or white rust.
1.2 The components may or may not have a surface treatment applied.
1.3 A limiting factor is the subjectiveness when determining actual percentage of rust or white rust corrosion.
1.4 Other performance characteristics of ferrous metal components such as abrasion resistance of barrier coatings are not evaluated in this method.
1.5 This test method was developed based on Practice G87.
1.6 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.
1.7 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.