Joist tape, Integrity Gasket, or something very similar is sold on at least half of the online sites that sell sound isolation products.  The consistent appearances online give legitimacy to this product and with the low cost associated for this joist tape it seems to make people feel inclined to give it a shot.  According to those who sell this product there are two functions for it: 1) To help isolate sound in high frequencies either through damping or decoupling (depending on which site is claiming what) and 2) to minimize squeaking between the joists and sub-floor.   The second purpose for this product may very well be accurate so we’ll focus on the first claim.

Can Joist Tape Isolate Sound?

Not really.  Best case scenario if you were to add the tape to a 2″ x 4″ wall with 1 layer of drywall on each side you will find an improvement of 1 STC point.  This rating is based on an unofficial test performed by someone capable of performing a legitimate test and not just speculation.

Here’s the story for the test mentioned above and a pretty good summary of the world of joist tape sales:

A customer interested in finding an effective and affordable way to isolate sound on his projects contacted a seemingly reputable online sound isolation product provider.  They told him if he added joist tape to one side of his wall and hung just one layer of drywall then he would find an improvement of 10 STC points.  So he followed their instructions and applied the strip, then hung the drywall, and then sealed all the angles and joints with their acoustic caulk.  He ran some tests on his newly isolated wall and received results that provided an increase of 1 STC point.  So he called up the supplier and asked them why it did not work as advertised.  They let him know he needed to add the joist tape to both sides of the wall to achieve the 10 STC point increase.  So he removed the drywall from the other side, added the tape, hung some new drywall, sealed the wall, and ran a test.  There was no increase in STC rating.  He called the supplier and was only able to reach their voice mail and did not receive a return call.  He decided to drop it and moved on to using resilient sound clips in his projects.

Why Does Joist Tape Not Work?

If the tape is intended as a damper then it will not be successful as the tape has no damping properties and the foam material used to make this tape is not considered a legitimate damping product.  If the tape is intended to decouple the drywall from the stud then it will also fail as the joist tape is immediately shorted once the drywall is screwed into the stud through the tape.  So in terms of damping and decoupling, the joist tape simply does not have the ability to perform as a sound isolation product.

Are There Similar Low Cost Alternatives To Joist Tape?

There are some other options that will provide more benefit than joist tape for minimal cost.  The most basic option is using a damping glue on your studs or joists before hanging the first layer of drywall.  The damping glue most commonly sold for this is Green Glue.  There are no sound tests to support the claim that Green Glue on the studs and joists will provide a significant increase in isolation, but this is a method commonly spec’d on commercial projects and the concept is simple/logical.

You may be wondering why Green Glue on the studs would be better than tape on the studs.  The reason for this is because Green Glue is considered one of the best damping products manufactured.  Green Glue will effectively reduces vibrations between the contact of the first layer of drywall and the stud/joists.  Green Glue in no way attempts to decouple the drywall from the stud so the fact that the screw passes through the glue to the stud will not affect performance.  In fact, it will improve the performance of the Green Glue because it will help the Green Glue compress between the stud and the drywall.

Our Advice

Applying any product between your stud or joist and the first layer of drywall will not isolate a significant amount of noise.  Using a product like joist tape or integrity gasket will not provide any increase at all.  If you want to squeeze out a couple extra STC points from your isolation efforts then applying Green Glue to the studs is a real affordable way to accomplish this.  In the end though, decoupling and damping the entire wall or ceiling rather than just the studs is always going to give you the best bang for your buck.

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