1. Acoustical
There are three types of sound associated with flooring materials:
- Impact sound is vibration generated by footfalls or objects coming in contact with the flooring surface that is transmitted to an adjacent room.
- Airborne sound is any airborne vibration such as voices, sound systems, etc that travels through the flooring system and into an adjacent room.
- Resonation sound is that portion of impact or airborne sound that reverberates or echoes within the room.
The International Building Code recognizes two types of tests to measure sound traveling through a floor/ceiling assembly and into a lower living space. Impact Insulation Class (IIC) testing for impact sound and Sound Transmission Class (STC) testing for airborne sound. American Society for Testing and Materials (ASTM) methods are listed for both IIC and STC tests.
Although resonating sound within the room is an essential element in the quality of a given living space, at the present time there are no established ASTM methods for testing this acoustical property. There are, however, proposed methods through other organizations that are currently under evaluation by NALFA.
Reports of sound test results should include a description of the entire floor/ceiling assembly.
Methods
- ASTM E 492 (Testing) & E 989 (Classification) - Impact Insulation Class (IIC)
- ASTM E 1007 (Testing) & E 989 (Classification) - Field Impact Insulation Class (FIIC)
- ASTM E 2179 - Change in IIC over a given concrete sub-floor - D IIC
- ASTM E 90 (Testing) & E 413 (Classification) - Sound Transmission Class (STC)
2. Compression Resistance
Compression resistance is the measurement of the force necessary to produce a specified percentage of compression over the entire top area of a given sample. The accepted percentage compression for test methods used to compare flooring underlayment products is 25%.
All of the methods listed for compression resistance testing describe testing at 25% of thickness. Results are expressed in either kPa or psi. The specific method selected should be noted when reporting results.
Methods
- ASTM D 3575 Suffix D
- ASTM D 1667 Sections 16-20
- ASTM D 3676 Section 13
3. Compression Set
Compression set covers the deflection of an underlayment specimen under a compressive force and under specified conditions of time and temperature, then noting the effect on the thickness of the specimen after releasing the compressive force. The results are reported as a percentage of the original thickness.
The methods listed are accepted procedures for measuring compression set. Both tests require deflection for a period of 22 hrs and release for a period of 24 hrs. The tests differ in the thickness of deflection (25% and 50%). The thickness of the test deflection should be noted along with the specific method selected when reporting results.
Methods
- ASTM D 1667 Section 21-25
- ASTM D 3575 Suffix B
4. Density
Volume density is the ratio of the mass weight of the underlayment to its volume. Density is calculated from thickness and weight determinations and expressed in pounds per cubic foot or kilograms per cubic meter.
Method
5. Water Vapor Transmission Rate
Standard methods for the evaluation of moisture resistance properties determine the rate of water vapor transmission through a given barrier material. The resultant Water Vapor Transmission Rate (WVTR) is the time rate of water vapor flow normal to the surfaces, under steady-state conditions, per unit area.
Methods
6. Tensile Strength
Tensile strength is the measurement of the force needed to separate or tear the underlayment. Tensile strength measurements may help compare underlayment materials for ease of installation and long-term wear-ability of the underlayment. Standard methods for the evaluation of tensile strength are conducted for both the length and width of the test material and are reported in lbs or kgs of force.
Methods
7. Thermal Resistance
Thermal resistance (R-value) is the reciprocal of thermal conductance (C-value). C-value is calculated from the thermal conductivity (k) of a material. Thermal conductivity (k) is the measure of the amount of heat that will be transmitted through a one inch thick piece of homogenous material, one square foot in size, in one hour, when there is a one degree Fahrenheit temperature change. The equation for "k" is: BTU * inch/sq.ft. * hr * deg F. C = k/thickness in inches. R = 1/C.
Method
8. Thickness
Thickness, which is normally measured in inches, mils or millimeters, is important when evaluating the finished flooring profile height as it relates to adjacent flooring material, doorway clearance and laminate accessory use.
Method
- ASTM D 3676 section 11 (referencing D-3767 method A-2)
- ASTM D 3575 section 8
9. Weight
Underlayment weight is usually expressed in lbs (or ounces) per square foot, or grams (or kgs) per square meter. Weight comparison may be an important characteristic when considering job site material management, ease of installation and freight cost.
Method
