Joint & Seam Filler is used to waterproof details in your wall assembly. This fiber-reinforced material can effectively span gaps up to 3/8 inches and, with the help of a back rod, can be used for gaps ranging from 3/8 inch to 1 inch. For voids larger than 1 inch, you can do structural repair or use SureSpan EX to span those voids.
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Where to Use Joint & Seam Filler
Joint & Seam Filler product is designed to be used wherever two materials meet, including:
- Board joints and board seams
- Corners
- Transitions between materials
- Penetrations
With its fiber reinforcement, Joint & Seam Filler is particularly useful for spanning gaps, ensuring a secure and durable seal. Additionally, it is an STP (silyl-terminated polymer) product, meaning it bonds to wet surfaces and cures through moisture exposure.
Applying Joint & Seam Filler to Board Seams
Follow these steps for the best results:
- Apply a Thick Bead: Run a generous bead of the filler straight down the center of the seam.
- Spread Evenly: Use a Bondo knife to spread the material thinly across the surface ensuring a minimum of 1 inch coverage on each side of the seam.
- Ensure Proper Thickness: The filler should be applied between 20 to 30 mils thick
Applying Joint & Seam Filler to Penetrations
When sealing around penetrations, follow these steps:
- Apply a bead of filler where the penetration meets the wall.
- Use a chip brush to evenly spread the filler, covering at least 1 inch on the wall and 1 inch on the penetration itself.
Next Steps
Joint & Seam Filler provides essential protection for seams and penetrations, preventing water intrusion and preparing the area for the air barrier wall system. Once the Joint & Seam Filler is applied, the next step involves further detailing with FastFlash or protecting the wall field with Cat 5 or Spray Wrap MVP.
By properly using Joint & Seam Filler, you ensure a durable, moisture-resistant surface, creating a solid foundation for your building wide air barrier.
