QuietGlue Pro vs. Green Glue

QuietGlue Pro and Green Glue: A Comparison

When Serious Energy first began their performance comparison test series, they attempted to replicate Green Glue’s 2005 results. However, they were not able to achieve the same results that had been previously obtained, despite following the application procedures outlined in Green Glue Company’s 2005 test report. Since 2005, Orfield Labs has significantly updated and improved their test equipment. Consequently, the only meaningful comparison between these products can be obtained from back-to-back testing – that means measuring the exact same wall assemblies with both damping glues during the same program of testing.

In further and multiple testing in 2011, including 35 day cure times, Serious Energy were still unable to reproduce the 2005 Green Glue results. In fact, while Green Glue Company has claimed their glue is “wet” at 14 days, it not only appears dry but more importantly, there is little to no difference in performance between 14 day cure times and 35 day cure times.

It is important to conduct all of these tests in a 3rd party lab, with damping glue dispensed and panels hung by 3rd party contractors, who treat all products the same. The same screw spacing, glue amount, drying time, edge sealing and panel orientation were strictly adhered to in all back to back tests.

The following results are based on recent back-to-back testing (2008 and 2010) commissioned by Serious Energy at Orfield Laboratories, the same test laboratory contracted by Green Glue for their testing in 2005 (see the Raw Data link above). These partitions were tested on the same wall frame on the same day. The transmission loss curves of a plasterboard partition, a QuietGlue 315 (discontinued product) partition, and the 2005 Green Glue partition are included as reference. Testing was performed with both 5/8” over 5/8” sandwiched as well as ½” over ½” on one side, as Green Glue did in 2005. In all cases, and over several years, Serious Energy were unable to reproduce the Green Glue Company’s 2005 results.

Figure 1 (below): A comparison of data from old and new laboratory testing. The old QuietGlue (QG315) appears here in yellow. All tests were performed as per the ASTM standard E90 in the same 3rd party lab with 5/8” plasterboard (2 layers on both sides except for the single-layer gypsum assembly), 2 tubes of damping glue per 4’x8’ panel, attached to single 2×4 wood studs spaced 24” ‘On Centre’ with 12” OC screw spacing.

Figure 2 (below): Chronological Green Glue test comparison from 2005 to 2011. Note the reduction in performance especially in the plasterboard coincidence frequency range (see Figure 5 for further detail). As the graph indicates, Serious Energy was not able to reproduce the 2005 Green Glue test results even in the same lab over a 3 year period with multiple tests.

Figure 3 (below): 2008 back-to-back test results with the same method, damping glue amount and same contractors. These results indicate that QuietGlue Pro equals or outperforms Green Glue.

Figure 4 (below): Back-to-back low frequency test results from 2008. Because this data is below 80 Hz and due to lab limitations (the NAVLAP certified low frequency limit of Orfield Labs is 80 Hz), it should not be relied on solely when comparing.

Figure 5 (below): The coincidence frequency is the frequency at which the structural wave of the plate or panel matches the acoustic wave, causing a “dip” in performance. For gypsum plasterboard this coincidence dip occurs around 2,000 Hz to 4,000 Hz. The magnitude of this dip corresponds to the quality of the damping system, a smaller dip indicating a better-designed panel. Note that QuietGlue Pro outperforms Green Glue by about 3dB throughout this range.

Repeatability of Results

An important part of qualifying any laboratory data is verifying the measurement repeatability. Serious Energy tested the same wall system, (demolished and then rebuilt) three times in a row to verify repeatability. The results of this test series are shown in Figure 6 below. At frequencies from 31.5 Hz to 5,000 Hz, all the transmission loss values for the entire test series were within 1dB. From this data, it can be concluded that a comparison of back-to-back transmission loss testing is meaningful and repeatable.

Ease of Use

Both QuietGlue Pro and Green Glue can be dispensed from the tube with a standard Quart Size caulking gun at more than 200 grams/second with a 9mm nozzle opening. This is under 10 seconds per tube. It takes longer with both products if one creates a small 3mm nozzle opening instead. This is not recommended for QuietGlue Pro. At 9mm, there is no substantial difference in ease of use between products.