Muddable J-Bead

Used to finish drywall edges when dissimilar materials and door and window encasements meet gypsum

Muddable J-Bead is designed to cover raw edges of drywall when butting up to other materials such as masonry, glass, door frames and window trims.

Application(s): Drywall

Raised shoulder and extensive perforations along flange ensure excellent finishing compound adhesion and flush finish. Moisture- and  thermal-resistant properties of rigid vinyl trims make for ideal use around bathtubs, showers, windows and skylights. Rust proof and dent resistant. Easy to cut and install. Available in 1/2" and 5/8" depths.

  • Moisture and dent resistant.
  • Raised shoulder and perforations enhance compound adhesion.
  • Produces finished edges at panel terminations.

Step 1:
Make sure the surface of the drywall is clean and smooth. Avoid using the tapered edge of the drywall board for this application. Measure and cut the Muddable J-Bead to length. Subtract ½” for vertical applications. Dry fit the bead to ensure the optimum fit.

Step 2:
Position the mud leg of the Muddable J-Bead so that it is facing the room’s interior. Slip the J-Bead over the edge of the drywall until both edges meet.

Step 3:
Install the drywall equipped with the J-Bead using screws as normal.

Step 4:
Staple the Muddable J-Bead every 6”- 8” with ½” staples while applying pressure by hand to keep the bead tight to the drywall surface.

Step 5:
Using a 6” taping knife, apply a coat of joint compound to the surface of the J-Bead’s mud leg. The use lightweight compound or setting-type compound in this step will reduce shrinkage and speed up the drying time. Let this dry completely, for several hours or overnight.  

Step 6:
Using an 8” taping knife, apply the final coat of joint compound. Feather the compound beyond the previous coat. The use of all-purpose compound or topping compound will make for a more durable finish. Let this dry completely, for several hours or overnight. 

Step 7:
Sand lightly with 120 grit sandpaper to finish.

Watch how the muddable J-Bead is installed in a Armstrong® module perimeter acoustical drywall system:


ASTM & Code Standards

  • ASTM C1047 - Standard Specification for Accessories for Gypsum Wallboard and Gypsum Veneer Base
  • ASTM D3678 - Standard Specification for Rigid Poly Vinyl Chloride (PVC) Interior Profile Extrusions
  • Installation: ASTM C840 - Standard Specification for Application and Finishing of Gypsum Board
  • SDS & Product Certification Information


All stored materials shall be kept dry.  Materials shall be stacked off the ground, supported on a level platform, and protected from the weather.


PRoduct submittal SHeets

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Product Code Description
MJB Muddable J-Bead

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