Hal Yardquay’s Blog

November 30, 2009

RC Assurance Clips

Filed under: Products — admin @ 12:03 am

What Are RC Assurance Clips and Why Do I Need Them?

The RC Assurance Clip acts as an impenetrable washer that puts extra space between the channel and the joist.  The snap on clip works with any resilient channel but is specifically designed for use with RC Deluxe from Dietrich.  RC Assurance Clips are used with resilient channel to eliminate the possibility of short circuiting your resilient channel installation.

RC Assurance Clips will not improve the performance of a successfully installed resilient channel system, but will ensure that your resilient channel installation is a success.  Almost every resilient channel installation will have at least one short and most installations will typically have short circuits in 15% or more of the connections.  While decent results can be accomplished with resilient channel, if you have multiple short circuits then the benefit of the resilient channel will be completely negated.

Developed a number of decades ago, resilient channel is one of the first sound isolation products used.  The popularity of resilient channel has been reduced significantly with innovations such as resilient sound clips and Green Glue, but resilient channel remains pretty popular in some parts of the United States.  One of the reasons resilient channel has become less popular is a huge and common issue with the installation of resilient channel.

The typical design and UL assembly calls for a fastener of 1”.  The typical installation utilizes a 1.25” or 1.5” fastener, mostly to aid in the “grab” of the screw to the channel.  This minor modification assures that 15% of the connections or more will be compromised and that the performance of the system will short circuit the low frequency transmission effectiveness of the system.  Now that lab tested 52 becomes a field 42.  The resilient channel needs another 0.375” to assure that connections are limited between the gypsum board and the joist assembly.  The RC Assurance Clip provides that space.

How Many Would I Need?

Each stud or joist that your resilient channel crosses will require an RC Assurance Clip.  The number of clips you need will depend on the spacing of your studs or joists and the spacing of your resilient channel rows.  Framing is typically 16″ on center and resilient channel is typically spaced 24″ on center.

Use this table below to help decide the number of clips you need.  Choose your framing spacing off to the left and the spacing for the resilient channel from the top row.  Then take your total square footage of all the areas where resilient channel will be installed and multiply it by the corresponding number below.  That will be a pretty good estimate of how many clips you will need.

12″ O.C. Spacing Of Resilient Channel
 24″ O.C. Spacing Of Resilient Channel
16″ O.C. Framing .65 multiplied by total square footage .50 multipled by total square footage
24″ O.C. Framing .60 multiplied by total square footage .35 multiplied by total square footage

So if you are putting resilient channel on an 8′ tall wall that is 12′ wide then you will need approximately 50 RC Assurance Clips if you space your resilient channel 2′ on center from floor to ceiling.  A quick calculation for how many clips you need can be accomplished by taking the total square feet of your wall or ceiling where you are installing the resilient channel and divide by two.

How Do I Install These Clips?

  • Resilient channels should be RC Deluxe as manufactured by Dietrich. Lawn Care Service in Boise, Star, Meridian, and Eagle Idaho.  Or equal dimensionally manufactured product.Nominal dimensions are:

    a. 2.5” overall width
    b. 0.50” thickness dimension
    c. 0.50” screw area for the RC Channel to the joist
    d. 1.50” screw area for gypsum board to RC Channel
    e. 25 gauge galvanized steel

  • RC Assurance is a spacer that is used in every location where a resilient channel is connected to a joist.
  • RC Assurance is designed to snap on to the 0.50” FLANGE of a resilient channel with the pinch point on the top and bottom. The 90 degree leg points down toward the open area of the resilient channel.
  • Spacing for Resilient Channels varies from UL Assembly & may be between 12.0” on center to 24.0” on center. Please consult your project specifications for proper spacing.
  • Layout all resilient channels, following the recommended guidelines of the Gypsum Contractors Association, UL & the project specifications.
  • FASTENING THE RESILIENT CHANNEL TO THE JOIST WITH RC ASSURANCE™
    For installation with RC Deluxe from Dietrich, snap enough RC Assurance onto the flange of the resilient channel to fasten the entire 12 foot section, one for each joist connection; RC Assurance will lock & slide to the proper position. Use a 1 3/4” Type “S” bugle head screw to fasten the assembly to the joist. Complete the installation of the channel leaving a small (0.125”) gap between the structural wall elements & the butt end of the resilient channel. Where possible, utilize the screw holes in the resilient channel but where alignment with the center of a joist does not work screw through the resilient channel to fasten to the joist.
  • SEAMING RESILIENT CHANNEL
    Most assemblies require a 4.0” overlap of resilient channel butt ends. For this application, slide the two flanges into the RC Assurance & screw through both pieces to fasten to the joist.
  • CONNECTING GYPSUM BOARD TO RESILIENT CHANNEL
    Consult the UL Assembly specification or the project specification for the type of screw to install. Typically, Type “S” or Type “W” bugle head screws are required. RC ASSURANCE is typically installed with 1.25” Type ”S” screw for the first layer of gypsum board and with a 1 7/8” Type “S” screw for a second layer.

DOWNLOAD THIS INSTALLATION GUIDE AS A .PDF

Conclusion

You only have one shot at attempting to isolate sound.  If you decide to go with a resilient channel system and you short circuit the channel then your efforts will not be effective.  RC Assurance Clips are very affordable and only add a cost of about fifteen cents per square foot to your project.  The benefits of the RC Assurance Clips is huge compared to the minimal cost which is why this clip is a must if you are planning on installing resilient channel on your project.

Click here to purchase RC Assurance Clips from our store.

November 23, 2009

Like Having A Freeway Running Right Through My Living Room

Filed under: Articles — admin @ 1:46 pm

Every passing car and truck is a reminder of why you were able to purchase your place for such a low price.  Dealing with exterior noise is obviously a very common issue–especially for those living in major metropolitan areas.  There are all sorts of products and wall constructions that can severely reduce exterior noise, but if you don’t treat the weakest points then you will end up with one expensive (and still pretty noisy) exterior wall.

A typical exterior wall is made up of a layer of drywall, 2″ x 4″ framing, R-13 insulation, a layer of OSB sheathing, and either siding, stucco, or brick.  Exterior walls will also of course have windows and a door every now and then.  The STC rating of your exterior wall will not be much better than your interior walls.  An STC rating for a regular interior wall will be somewhere in the low to mid 30’s while your exterior walls are usually in the high 30’s to low 40’s.

The first thought by most customers is to purchase a ’save-all’ sound isolation product to make all their troubles go away.  Whether you buy Green Glue, resilient sound clips, mass loaded vinyl, heavy exterior doors, ’soundproof’ windows, specialty insulation, or whatever other product someone is willing to sell you; your efforts will not be successful if you don’t incorporate multiple methods to improve sound isolation.

Deal With Your Weakest Links First

Exterior doors typically perform decently because they are usually solid wood and sealed very well from the exterior elements.  So while the doors aren’t the best for isolating sound, they are not usually the weakest link.  Windows, on the other hand, can transmit sound almost as well as they transmit light.  ;-)   The average STC rating of a window is in the high 20’s, about 1/2 the isolation properties of your exterior wall, ouch!

Replacing your windows with ’soundproof’ windows may help performance, but you will have a major construction project to undertake.  You will need to essentially remove a 4″ or so perimeter around the window to remove the existing window and install a new window.  If the exterior of your house is rock, brick, or stucco then this can be a major project.  Avoid this headache and high cost by adding a second window on the inner part of your window frame.

Adding a second window will increase isolation in two ways: 1) by adding an air gap between the exterior window and the newly installed interior window and 2) by adding an extra path for sound to have to travel through.  Simply adding a second double pane window you will increase the STC rating between your two windows to the mid to high 40’s.  At that point your windows will perform better than your thick exterior walls!

There are several companies that sell windows that can be used for retrofitting on the interior side of your windows sill.  Run a Google search or humor the Microsoft guys and try their new Bing to find a company near you that sells retrofit windows.

Watch the video below to see the effect of adding a second window to your window installation.

Now, Let’s Improve the Rest of Those Walls of Yours

Your windows now have an STC rating of almost 50, yipee!  Now you need to continue on fixing your new weakest link, your walls…

As I mentioned before, your exterior wall STC rating is likely somewhere in the high 30’s to very low 40’s.  The most basic way to improve your walls at this point with minimal demolition would be to add a layer of 5/8″ drywall with Green Glue at a rate of 2 tubes per 32 square feet.  Adding the Green Glue is simple, the hardest part will be to hang, tape, and texture the drywall.  Adding the Green Glue and additional layer of drywall will bring your STC rating up to the low to mid 50’s and will improve low frequency isolation significantly.

Now your walls will perform just as well as your windows and without major investment into your project this is likely as good as it will get.  You can add decoupling to this scenario to increase isolation, but this will involve removing the wall’s current layer of drywall.

If you would like to go this far then you will need to remove the drywall to avoid a triple leaf effect and then add resilient sound clips with hat channel to your studs.  After removing the drywall, rather than using clips you can also build another 2″ x 4″ wall in front of the current exterior wall, insulate the newly framed wall, and then hang a layer of drywall on the new wall.  This will improve the performance of your walls quite a bit more than a layer of Green Glue ever could and even better than a resilient sound clip system could.  The problem with this though (other than having to sacrifice another 6″ or so of floorspace) is your wall will be big and beefy with a great STC rating, but your freshly installed second window will still be rating in the high 40’s.

If your double stud wall has a rating of around 70 STC and your windows are high 40’s STC, then your final STC value for your wall will be much closer to the window rating than the uber-high double stud wall rating.

Conclusion

If you want to keep exterior noise out of your sanctuary then start by improving your weakest links.  Improve your windows and make sure you have a quality exterior door that is well sealed.  If that does not satisfy your appetite for sound isolation then add a layer of drywall with Green Glue or a similar damping compound (ie, Decibel Drop, QuietGlue, QuietRock) in between.  Don’t forget to get your windows cleaned in the treasure valley area by Clear Impressions Idaho.  Boise Window Cleaning

Still have questions?  I guess we didn’t explain the topic well enough.  Let loose, ask us a question or two.

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