Physical Address
304 North Cardinal St.
Dorchester Center, MA 02124
D226 – Standard Test Method Technical Guide
📐 Classification and Material Requirements
ASTM D226/D226M-17 (Reapproved 2023) covers asphalt-saturated organic felts, with or without perforations, intended for use with asphalts conforming to Specification D312/D312M in the construction of built-up roofs and with asphalts conforming to Specification D449/D449M in the construction of waterproofing systems. The standard establishes two specific product classifications: Type I, commonly called No. 15 asphalt felt, and Type II, commonly called No. 30 asphalt felt.
In the process of manufacture, a single thickness of dry felt must be saturated with an asphaltic saturant. The felt must be produced principally from organic fibers. The surface of the felt must be uniform and relatively smooth. Upon splitting or tearing on the bias, the felt must appear reasonably free of lumps or particles of foreign substances, ensuring consistent quality and performance in a built-up assembly.
⚙️ Physical Properties and Performance Criteria
The material must conform to the physical requirements prescribed in Table 1 and the dimensions and masses prescribed in Table 2 of the standard. A key performance benchmark for field handling is that the finished product must not crack nor be so sticky as to cause tearing or other damage upon being unrolled at temperatures between 10 °C and 60 °C (50 °F and 140 °F).
| 🟦 Property | 📐 Type I (No. 15) | 📏 Type II (No. 30) |
|---|---|---|
| Fiber Basis | Principally Organic Fibers | |
| Surface Quality | Uniform and relatively smooth; free from lumps or foreign particles when split on the bias | |
| Unrolling Temperature Range | 10 °C to 60 °C (50 °F to 140 °F) | |
| Condition upon Unrolling | No cracking or sticky tearing | |
| Perforations (If Specified) | Uniformly spaced, conforming to all physical requirements of the plain type | |
Perforated felts must conform to the same requirements as the plain type but must also include uniformly spaced perforations. These physical requirements ensure the felt integrates properly with hot asphalts and provides reliable performance as a substrate in roofing and waterproofing systems.
📊 Testing Framework and Referenced Standards
Conformance to this specification is verified using several key ASTM standards. Sampling and testing of the saturated felt is performed in accordance with Test Methods D146/D146M. The asphaltic saturants must independently meet the requirements of their respective specifications depending on the end-use application. The kerosine number of the unsaturated dry felt is evaluated using Test Method D6136/D6136M.
| ⚡ Referenced Standard | 🎯 Purpose in D226/D226M |
|---|---|
| D146/D146M | Test Methods for Sampling and Testing Bitumen-Saturated Felts |
| D312/D312M | Specification for Asphalt Used in Roofing (Type I/II applications) |
| D449/D449M | Specification for Asphalt Used in Dampproofing and Waterproofing |
| D6136/D6136M | Kerosine Number of Unsaturated (Dry) Felt by Vacuum Method |
| D1079 | Terminology Relating to Roofing and Waterproofing |
⚠️ Critical Instruction on Units
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.
📌 User Safety Responsibility
The safety hazards caveat in Section 8 (Test Method portion) of this specification clarifies that the standard does not purport to address all safety concerns. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
❓ Frequently Asked Questions
🔍 What is the difference between Type I and Type II felts?
Type I is commonly known as No. 15 asphalt felt, while Type II is commonly known as No. 30 asphalt felt. Both must meet the same general requirements for manufacture, organic fiber content, surface uniformity, and temperature resistance during unrolling.
💡 What temperature range must the finished product withstand during unrolling?
The felt must not crack nor be so sticky as to cause tearing or other damage upon being unrolled at temperatures between 10 °C and 60 °C (50 °F and 140 °F).
⚡ Are perforated felts held to a different standard than plain felts?
No. Perforated felts must conform to the same physical requirements as the plain type. The only additional requirement is that the perforations be uniformly spaced across the material.
📌 Is it acceptable to combine SI units and inch-pound units in a specification?
No. Each system of units (SI or inch-pound) must be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.