Sashco Pre-Caulking Filler Rope is a round, closed-cell foam backer rod with a water-resistant skin. Press it into a joint before you caulk or chink and it does three jobs at once: it fills the void so you use less sealant, it insulates the gap, and it acts as a bond breaker. Sealant grabs the two sides of the joint but will not stick to the rod, so the bead can stretch and compress with seasonal movement instead of tearing loose. The round profile also helps you tool the hourglass-shaped bead that sealant manufacturers ask for.

• Size: 1-1/4" diameter x 50 Ft roll
• Color: Gray
• Closed-cell foam with a water-resistant skin - repels water to protect the joint from damage
• Bond breaker: sealant adheres to the sides of the joint, not to the rod, so the bead can move
• Fills the joint so you use less caulk or chinking
• Compatible with all substrates and sealants
• Interior or exterior use - log courses, cracks and checks, sidewalk and driveway cracks, door and window frames, sill plates, butt joints, and wall cracks
• Will not fit a joint smaller than 1/4" wide or 1/4" deep

Sizing: Sashco recommends a rod one size SMALLER than the width of the joint - for a 1/2" wide joint, use the 3/8" rod. Press the rod in evenly, leaving 3/8" to 1/2" of open space at the top of the joint for the sealant.