HushFrame Raft

$4.95
per piece
Lead Time: 1-3 DAYS
  • High performance drywall decoupler for walls and ceilings
  • Use with wood furring or metal furring hat channel with 1/4" to 1" of space lost (plus drywall)
  • Exceptional STC and IIC test results, including multiple UL assembly ratings for fire safety
  • Delivers 7 days a week to residential addresses
  • Shipping Map from Utah and Georgia
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View our Product FAQ for answers to common questions about HushFrame Rafts.

The HushFrame Raft Connector is the newest invention for decoupling drywall from wall and ceiling structures. Decoupling is not a new concept in sound isolation, but the Raft provides unique benefits over competing products. This wood based product is connected between a soft, yet extremely strong, rubber silicone. The energy from sound is lost in the transfer from the front of the Raft to the base of the Raft via the rubber silicone. The end result is significant isolation gains in STC and IIC for both walls and ceilings, even in the most basic of assemblies. No other products are needed to meet or exceed building code for STC and IIC in walls and ceilings. HushFrame Rafts with single layer drywall and no underlayment on the floor above is all you need. Simple fool proof installation for a simple assembly with exceptional performance!

  • Installs to the side of the framing, whether wood or steel, either flush with the face of the framing or recessed into the cavity. Flush installations lose 1" of space and recessed installations lose as little as 1/4" of space (plus the thickness of drywall).
  • Standard 1x wood furring or metal furring hat channel can be used.
  • When wood furring is used on ceilings, all interior walls can be built beneath the decouple ceiling and fastened directly to the wood furring. When wood furring is used on walls, cabinets (both upper and base) can be fastened directly to the furring.
  • Works in both standard or recessed installations meaning you can mix and match installation style without buying different types of connectors and more costly connectors.

50 STC and 50 IIC ratings in wood structures can be attained without the addition of rubber underlayment, Green Glue Compound, mass loaded vinyl, or double layer drywall. This makes for a very cost effective assembly that meets or exceeds building code requirements. Add a second layer of drywall and your STC is over 60 and your IIC is 56. An incredible amount of isolation with such a minor investment in cost, and if installed recessed with furring parallel to the joists, then only 1/4" loss of headroom!

IMPORTANT INSTALLATION NOTE: It is crucial to verify all HushFrame Rafts within the surface assembly are on an even plane and fastened with full contact with the framing and flush to the face of the joist or stud. Framing that is uneven should be leveled, either through planing the protruding framing or shimming the recessed framing before attaching the Rafts and furring. If an effort is not made to install the Rafts to a level framing assembly, then the risk of the Raft shearing and causing total failure is a possibility. System failure caused by installation on uneven joists is the responsibility of the installer.

The number of Rafts required will depend on the weight the Raft system is expected to support. If your system is simple with 1 or 2 layers of drywall installed (or any similar thickness and similar weight panel), then the layout will be consistent throughout the ceiling or wall assembly.

To support 1 or 2 layers, estimate 1 Raft for every 4 square feet (Rafts spaced at a max of 48" apart in rows at a max of 24" apart). Max load is 11.7 pounds per square foot.

If you include mass loaded vinyl, Green Glue Compound, or any other material that will increase the overall weight of the assembly, then include this in your estimate. Increase the weight capacity of the Raft system by reducing the space between each Raft. Reduce the Raft spacing from a max of 48" to 32" and the spacing of each row from a max of 24" to 16", depending on the amount of weight supported.

If you are adding weight to the assembly in specific areas (TV mount, cabinet, projector, projection screen, acoustic products, etc), then increase the quantity of Rafts in and around those specific areas to avoid over loading the Raft system. Do not add up the overall weight of these items and then average out the overall weight of the entire assembly. The increased weight is specific to that location and the Raft spacing should be adjusted in those areas specifically.

All leftover material is returnable within 60 days, so we recommend ordering more than you will likely need and returning the additional Rafts when the project is completed.

IMPORTANT INSTALLATION NOTE: It is crucial to verify all HushFrame Rafts within the surface assembly are on an even plane and fastened with full contact with the framing and flush to the face of the joist or stud. Framing that is uneven should be leveled, either through planing the protruding framing or shimming the recessed framing before attaching the Rafts and furring. If an effort is not made to install the Rafts to a level framing assembly, then the risk of the Raft shearing and causing total failure is a possibility. System failure caused by installation on uneven joists is the responsibility of the installer.

Download IsoStore's Installation Guide 870 KB

Download the Manufacturer's Installation Guide 8.3 MB

The HushFrame Raft is installed flush with the side of the framing or recessed for a lower profile installation. If installed flush with the side of the framing, then the wood furring or hat channel will run perpendicular to the framing. If installed recessed for a lower profile installation, then the wood furring or hat channel will run parallel to the framing. This is the same for both wood and steel framing in both walls and ceilings.

Fastener for the Raft to the structure: (2) 1-5/8" framing screws or (2) 1-1/2" medium crowned staples or (2) 6p ring shank sheating nails

Fastener for the wood furring to the Rafts: (1) 2" framing screws or (2) 1-5/8" framing screws located in the center 2/3rds of the furring mount (fluted tip screws recommended to reduce furring splitting)

Fastener for the metal furring to the Rafts: (2) 1-1/4" self-tapping screws through each shoulder at a 45-degree angle into the Raft furring mount

We recommend a staggered layout with Rafts distributed to each stud or joist. Accomplish this by installing your first row of Rafts at max spacing, then your next row will offset by one joist and so on with the next row. Ultimately each Raft within each row will be at the max spacing allowed. The offset spacing will allow each stud or joist to have at least some Rafts attached. Refer to the location of the Rafts in the drawing below titled 'Perpendicular Channel Installation'.

Review the quick animated installation video below for a simple explanation of how this product installs.

Drawing How To Install HushFrame Rafts to Framing

HushFrame Raft Connector Specs
Coverage 1 raft per 3.5 square feet
Dimensions 4-7/8" x 2" x 2-1/4"
Added Depth 1/4" to 1", depending if Raft is recessed or flush with side of framing
Material Wood and silicone rubber
Fire Ratings
Class 'B' Fire Rated. 1 hour UL assemblies: U263 (ceiling), U311, U340, U344, W307 (load bearing walls - single, staggered, shear walls, and exterior walls)
Spacing Follow standard 24" on center spacing for most areas. 8" on center spacing on the short edge of each panel where two panels come together.
Fasteners Use 1" or longer coarse thread framing screws
Load Limit Recommended max 50 pounds shear and 80 pounds tension. Failure only at 3 times the weight for both shear and tension.
Performance Adds 14-21 STC points to standard wall. Adds 10+ STC points and 14-18 IIC points to standard floor/ceiling.
Version 300 Series
HushFrame Raft Connector Downloads
HushFrame Raft Product Data and Submittal Sheet DownloadPDF 262 KB
Manufacturer's Installation Guide DownloadPDF 870 KB
IsoStore's Installation Guide DownloadPDF 8.3 MB
HushFrame Raft Spacing DownloadPDF 544 KB
HushFrame Raft Steel Stud Installation and Test DownloadPDF 1.4 MB
HushFrame Shear Test DownloadPDF 3.13 MB
HushFrame Tension Test DownloadPDF 2.87 MB
UL Assembly Test Report DownloadPDF 5.8 MB

The performance gains achieved in wood or metal structures with HushFrame Raft Connectors are significant. The HushFrame Rafts have been been tested for STC, OITC, IIC, and is a Class B Fire Rated product with an approved 1 hour UL rating.

*All test results shown in this table were achieved through third party testing from accredited laboratories. The full test is available upon request.

Independent Sound Test Results
Type Assembly STC IIC
Exterior Wood Wall Base assembly, 2x4 framing, 1 layer drywall interior, 1 layer Hardi exterior 47 -
Exterior Wood Wall 2x4 framing, 1 layer drywall on HushFrame Rafts interior, 1 layer Hardi exterior 57 -
Interior Wood Wall Base assembly, 2x4 framing, 1 layer drywall on both sides 39 -
Interior Wood Wall 2x4 framing, 1 layer of drywall on HushFrame Rafts, 1 layer of drywall on other side 53 -
Interior Wood Wall 2x4 framing, 2 layers of drywall on HushFrame Rafts, 1 layer of drywall on other side 57 -
Interior Wood Wall 2x6 framing, 1 layer drywall on HushFrame Rafts, 1 layer drywall on other side 56 -
Interior Wood Wall 2x6 framing, 2 layers of drywall on HushFrame Rafts, 1 layer drywall on other side 60 -
Interior Wood Wall 2x6 framing, 2 layers of drywall on HushFrame Rafts, 2 layers of drywall on other side 63 -
Steel Studs 2x6 Staggered steel stud, 1 layer drywall on both sides 58 -
Steel Studs 2x6 Staggered steel stud, 1 layer drywall on HushFrame Rafts, 1 layer drywall on other side 67 -
Steel Studs 2x4 20 gauge steel stud, 2 layers of drywall on HushFrame Rafts, 2 layers of drywall on other side 65 -
Steel Studs 2.5" 25 gauge steel stud, 1 layer of drywall on HushFrame Rafts, 1 layer of drywall on other side 54 -
Steel Studs 2.5" 25 gauge steel stud, 2 layers of drywall on HushFrame Rafts, 2 layer of drywall on other side 64 -
Wood Ceiling Joists Base assembly, wood joists, 2 layers of OSB on the joists, drywall ceiling suspended by wood furring strips 50 38
Wood Ceiling Joists Wood joists, 2 layers of OSB on the joists, ceiling suspended with HushFrame Rafts, 1 layer of drywall 59 50
Wood Ceiling Joists Wood joists, 2 layers of OSB on the joists, ceiling suspended with HushFrame Rafts, 2 layers of drywall 61 56

*Performance gains by adding a layer of drywall to either side of the wall were consistent between 2x4 and 2x6 wood framing.
**Wood furring was used on wood assembly tests, metal hat channel was used on steel stud tests.