Resilient Sound Clips
Resilient sound clips are isolation mounts that install in rows directly to the ceiling or wall framing. The resilient clips then have furring hat channel attached via pressure fit and layers of drywall or wood fasten to the channel. Decoupling is the most effective way to isolate sound over all other methods including damping, mass, and absorption products.
Short answer, yes.
Long answer, installing over rigid surfaces like drywall or plywood is possible, but will seriously reduce performance. Reduce the loss in performance with R-6 fiberglass batt insulation between the furring hat channel and the existing surface. We recommend doing this after installing the clips and channel so the channel can support the insulation. Review the GenieClip® product page for ratings on retrofit installations.
We show both layout options on our resilient clip install guide. Both will provide excellent performance. Standard layout will use fewer clips and install quicker. Staggered layout will help distribute the load of the drywall evenly.
All sound tests for any brand of resilient sound clip use the staggered layout.
Yes. You may want to consider the staggered layout in ceilings with joists less than eight inches in depth.
A high quality resilient sound clip will maximize isolation performance for airborne, impact footfall, and structural noise. Low, mid, and high frequencies are isolated with resilient sound clips.
Single layer drywall is the minimum of course and acceptable when clearance is of concern or when resolving mid to high frequency sound problems. Double layer 5/8″ is recommended for most projects. Triple layer 5/8″ is recommended in areas where low frequencies are of concern.
Wood Framing: #8 x 2-1/2″ coarse thread wood or drywall screw
Steel: #8, #10, or #12 x 1-5/8″ self tapping, fine thread, Type-S
Concrete: 3/16″ or 1/4″ x 2-1/4″ anchor screw (Tapcon)
Splicing Channel: 1/2″ pan head steel stud framing screw or similar
Drywall to Channel: Fine thread or coarse thread drywall screw, determine the length by adding minimum 1/2″ to thickness of layers being fastened.
Yes, of course. The structural support of a resilient sound clip system is several times that of the actual weight of drywall you will be suspending. The reason we stress the spacing of hat channel based on the weight of the assembly (layers of drywall) is just for acoustic load per clip, not structural support.
Ceilings are heavy and more rigid, whereas walls are easier to isolate because they are lightweight. Adding decoupling, damping, and mass to a lightweight wall will provide greater results than adding the same products to a heavy, rigid ceiling.
An STC rating of 52 in a wall with Green Glue Compound will likely yield a mid-40’s STC in ceilings. An STC rating of 64 in a wall with GenieClips® RST will yield an STC 54 in a basic ceiling assembly.
If treating the ceiling only, then yes. Using products like damping compounds, pre-damped drywall, mass loaded vinyl, sound board, extra layers of drywall, etc., will not help with isolating footfall noise. However, the damping compounds and extra layers of drywall will help increase performance on a resilient ceiling.
Furring hat channel is a steel stud framing member that pressure fits into the resilient sound clip. The sizing is pretty universal, typically manufactured at a 2-1/2″ width that expands up to 2-7/8″ while stocked. Drywall distributors, local building supply stores, and steel stud suppliers are typically the best sources for hat channel. Resilient channel is not the same as furring hat channel. Make sure not to purchase or use the word resilient when describing the channel.
When purchasing hat channel, ask for:
25 gauge, hemmed edge, 7/8″ tall, furring hat channel
We recommend 24″ on center spacing for hat channel rows when installing single or double layer drywall (up to 6 pounds per square foot of material).
We recommend 16″ on center spacing for hat channel rows when installing triple layer drywall (up to 9 pounds per square foot of material).
Choosing A Clip
When selecting a clip, we recommend reviewing sound tests, UL tests, quality of design, and the materials used in the clip. That alone will weed out several clips that have limited to no testing in both sound and fire tests.
The other points to consider are the materials used in the clip and quality of design/engineering for the clip. Does the design of the clip even make sense? Is the base of the clip just metal or plastic or some indescribable foam? A well designed resilient clip will have a resilient base, a nice thick sturdy metal to hold the channel, and a design that decouples the head of the attaching screw from the clip and framing as much as possible.
So don’t get caught up in advertised STC ratings or OITC ratings. They can be inaccurate, inflated, or simply estimated rather than actual ratings.
While we sell many clips, and at this point we have sold every clip on the market, we strongly support the GenieClip® RST by Pliteq. Here are a few reasons why:
- Over 150 sound tests in various ceiling and wall assemblies in both lab and field conditions.
- Currently 40 UL approvals in many different assemblies.
- A well engineered product from the design of the rubber, the characteristics of the rubber, the strength of the metal in the clip, and the consistent manufacturing from one clip to the next.
- Pliteq is a straight forward and honest manufacturer with a reputation for accurate and consistent product testing.
- Even with all the millions spent in testing the GenieClip® RST, it still remains very competitive in pricing.
The GenieClip® RST is fully tested for STC, OITC, IIC, has multiple UL ratings, structural load tests, and more. The design and production quality of the clip is much higher than any other clip available. The sound tests are consistent and numerous, completed in multiple acoustic labs or in the field over several years. The tests are done without tricks to juice the ratings.
Other clips usually have limited sound testing from a single acoustics lab years ago. The sound tests use tricks like thicker insulation or a wider framing span. The real world performance gain of $2 resilient clips is about equal to using resilient channel.
The savings with these types of clips may seem significant initially, but when considering the overall project cost and the performance lost with the lower performing clip, it is not worth the difference in price. Replacing the cheaper clips after the low performance is realized will be difficult and costly.
Most assemblies require UL rating whether it is for commercial or residential. You can certainly get away with installing clips that are not UL rated in residential construction and even some light commercial construction.
Even if a UL rating is not required by building code you should still use a fire rated product. The extra cost is negligible and sometimes UL rated clips are even less than non-UL rated brands.
Comparing Decoupling Methods
Resilient sound clips are installed directly to the framing roughly every five square feet using a basic pattern with furring hat channel attached to the clip creating rows that will be used to hang drywall or plywood. This installation will decouple the drywall or plywood from the framing by about 1-1/2″.
Resilient channel installs in rows spaced 16″ or 24″ apart attached directly to the framing with connections at each framing member. The one-legged design of the resilient channel is meant to have the leg of the channel attached to the framing with the bulk of the resilient channel free floating. The drywall or plywood is screwed into the free floating portion of the channel in a way that does not connect back into the framing. This installation will decouple the drywall or plywood from the framing by about 3/8″.
A successful installation of resilient channel is very uncommon. Most installers will accidentally screw the drywall into the channel and then into the framing. This mistake, known as a short circuit, significantly reduces the performance of the resilient channel and sometimes completely eliminates the performance gains that could have been achieved. Resilient sound clips and furring hat channel cannot be short circuited unless the installer uses a screw that is several inches long.
Even with a proper installation of resilient channel, a high quality resilient sound clip still rates several times better in STC, IIC, and OITC. This is due to many factors including increased air gap with the resilient clips (1-1/2″ vs. 3/8″), added benefit of a thick rubber base (assuming a clip like the GenieClip® RST), fewer connections (one every five square feet for the clips vs. one every framing member for resilient channel), and significantly more resilience because the channel is free to flex between the clips.
As a material, furring hat channel is just as resilient as resilient channel. The resilient channel though is connected to the assembly through hundreds of connections which keeps the resilient channel from really fully flexing and ultimately dissipating energy (isolating sound). Resilient sound clips allow the furring hat channel to flex because each clip holding the channel is spaced four feet apart. This increases resilience and increases isolation across all frequencies.
This clip, found online under a few different names, is a good clip with an interesting design. Some claimed advantages by the manufacturer are extra decoupling of the hat channel because the channel is embedded in rubber and easier installation because you can attach the clip to the hat channel and then install both the hat channel and clip at the same time. The obvious problems with these claims and some other deficiencies for this clip are:
- It does not matter if the claim of extra decoupling of the hat channel because the channel is embedded in rubber is accurate or not. The tested performance is what matters. All sound tests performed on this clip by the manufacturer will show that the clip performs well, but still under the majority of resilient clips you will find for sale online.
- The claim for easier installation is not realistic if you really think about it. With full 12′ pieces of channel, which isn’t always the case, the channel is often much shorter, you can put at most three clips on the channel. You still have to chalk line for the clips and channel to make sure you install them straight. Just because a 12′ section appears straight, does not mean it will line up with the next 12′ section or the one following that. Your rows can easily be off by an inch from one end of the wall/ceiling to the other end. That will become a major problem for your drywall hanger when trying to find the channel.
- The attaching screw head rests against the metal end which wraps around the clip and comes in direct contact with the framing. In the end, the testing is what is important, but that is a clear design flaw that likely reduces the performance of the clip to give it the overall lower rating it does have.
- With most clips, the acoustical load is what we worry about. From what we have heard from the manufacturer of this clip, there appears to be some concern over the structural support when installed on a ceiling. Not that you can’t install the clip on a ceiling, but with a double layer drywall assembly you may need to tighten the spacing of the clip. This decreases flexibility, reduces the performance, and adds extra cost in clips.
Most the testing you will find for double stud and staggered stud framing are lab tests for walls only. We still have not seen a sound test of any kind for a ceiling with independent joists. However, the concept of decoupling with framing is well established, so there is no reason to assume an independent ceiling joist is not significantly better than a standard fixed joist. The real question is how resilient sound clips compare to double stud walls, staggered stud walls, and independent joists.
Staggered Studs vs. GenieClips® RST
The STC rating of a staggered stud wall with double layer drywall on one side and single layer drywall on the other side is STC 47. The transmission loss in decibels at key low frequency points of 80Hz and 100Hz are 29 and 36. The STC rating of a GenieClip® RST system in the same type of assembly is STC 61. The transmission loss in decibels at key low frequency points of 80Hz and 100Hz are 27 and 33. You can see the GenieClips® RST perform 14 points higher in STC (every five points a doubling effect) and just a few points lower in the lowest frequencies. This performance loss in low frequencies can be made up by adding a third layer of drywall either on the clips or on the other side of the wall. This extra layer will change the 80Hz and 100Hz performance of the GenieClips® RST to 31 and 39 and increase the STC even further to an impressive STC 64 now exceeding the staggered stud wall in performance without taking up additional floor space. The tests referenced were done in the same lab so comparing the two isolation methods is accurate.
Double Stud Walls vs. GenieClips® RST
The STC rating of a double stud wall with double layer drywall on one side and single layer drywall on the other side is STC STC 64. The transmission loss in decibels at key low frequency points of 80Hz and 100Hz are 35 and 40. This is clearly a high rating in low, mid, and high frequencies. The double stud wall will rate 3 STC points higher than the GenieClips® RST in the same assembly and even more significant gains in low frequency performance when comparing head to head with GenieClips® RST in a similar mass assembly. However, adding that additional layer of drywall to the GenieClips® RST or to the other side of the wall will increase the STC to match the performance of the double stud wall and the 80Hz performance within 4 points with the 100Hz performance now just within 1 point.
Independent Joists vs. GenieClips® RST
This is a tough one because there are no tests for independent joists that we can use to compare to the GenieClips® RST. The concept of framing in independent joists, meaning joists that are separate from the structure and used to support the ceiling drywall only, definitely makes sense. It’s not a crazy assembly or gimmicky approach. We expect the performance of this method to be very high and likely similar to what a double stud wall can accomplish, but adjusted for a typical ceiling rating. Since GenieClips® RST with four layers of drywall will rate nearly the same as a double stud wall with three layers of drywall, we believe it is safe to assume that this performance comparison will be comparable in a ceiling assembly.
Lab vs. Field
The testing discussed above was all done in the same lab and not in the field. In doing so, they are only comparing the performance of the isolation method and not the performance of the isolation method in relation to the entire assembly (adjacent walls, floors, ceilings).
Staggered stud walls – The problem you will find with staggered stud walls is while the studs are offset and decoupled, they share the same top plate and bottom plate framing which tie directly into the ceiling joists and sub- floor. This is a major flanking issue. The staggered stud wall is already shown to be an average performer considering the effort in construction, but in field tests it will rate even worse. A staggered stud wall with clips installed is a great idea for increasing low frequency isolation, but a staggered stud wall alone is really overrated.
Double stud walls – In the lab there is no concern over flanking so the results can be misleading. If you use independent joists with double stud walls, then the top plate connection is not a concern. The floor flanking exists whether you have double stud, staggered stud, or a resilient clip system so that issue must be addressed separately. Most assemblies though will tie the second stud wall into both the ceiling and floor without the same break in materials that you have from one stud wall to the other. So your overall assembly is a double stud wall assembly, but your new stud wall transmits sound easily into both the ceiling and the floor. So the performance gains in the lab are significantly reduced. Not to mention the fact that you will lose in floor space at least the depth of the framing and a 3″ gap between the existing and new stud wall. That is a 6-1/2″ loss in floor space vs. a 1-1/2″ loss in floors space with resilient clips.
Independent joists – A great way to isolate the ceiling, but can become very complicated in the field. Here are a few problems with setting up a system like this. One, you won’t have much room for lighting and really no room for recessed lights since each joist will need to fit within two existing joists. Two, you won’t have much room for HVAC duct work. Three, if duct work, electrical, and plumbing already exist in between the joists then installing the independent joists can be very complicated. The only way to resolve these issues is to drop the entire joist, or most of the joist, beneath the existing joists rather than in between the joists. Problem is you will lose a serious amount of head room. Impossible for ceilings 8′ and lower without reducing head room to unusually low levels and not attractive for ceilings 9′ or lower. Independent ceiling joists will also require the use of double stud walls, or at least newly framed walls, resulting in both loss in head room and loss in floor space. It definitely works, but your room will really tighten up quick.
Improving A Clipped Assembly
In walls, add mass and damping to increase isolation in all frequencies.
In ceilings, you can add mass and damping to increase the STC and IIC rating (airborne and footfall noise). Add a resilient underlayment or damping to the floor above to increase the STC and IIC rating further.
We suggest standard the following materials for these areas:
Mass: 5/8″ drywall for mass in walls or ceilings, 1/2″ or thicker plywood in floors
Damping: Green Glue Compound to dampen walls, ceilings, and floor
Underlayment: GenieMat® RST02 or GenieMat® RST05 in the floor if the ceilings below are decoupled with GenieClips® RST
Including damping or pre-damped drywall is valuable in a resilient system. Expect significant increases in isolation of both airborne and footfall impact noise, as well as dissipation of vibrations over distance. Resilient clips can achieve high STC and IIC ratings but cannot reduce flanking to the extent of damping compounds.
No, not at all. Sound tests have shown adding MLV to resilient sound clip systems provides little to no gains. It may help slightly with resonance in lightweight wall assemblies. However, this can also be resolved with additional mass at a fraction of the cost.
We strongly recommend insulation. The type of insulation does not matter. Regular fiberglass batts are great, or something else soft and fluffy will do the trick. Insulation has increased value in decoupled assemblies because the path through the framing is decoupled leaving transfer between the framing as the best possible path. Add some insulation to lower the resonance point of the assembly.
Yes. Recessed lights equal lost mass and a reduction of 1-2 STC points per light. Restore this lost mass with the QuietBox. Use the GenieClip® LB to install the QuietBox resiliently in a decoupled ceiling.