Reliabilt-window-mull-kit-instructions -

: Open the window sashes to access the factory pre-drilled holes or specific reinforcement areas. Drive the provided screws through one frame into the other (staggering them if necessary) to pull the units tightly together.

: You can find series-specific PDFs (e.g., Series 105 or 150) on the ReliaBilt Installation Support page . reliabilt-window-mull-kit-instructions

: Run a continuous bead of 100% silicone sealant along the entire length of the channel where the windows will connect. This step is critical for preventing air and water leaks. : Open the window sashes to access the

: Apply additional silicone sealant to the top and bottom of the mull joint, filling any voids. If your kit includes a drip cap or mull bridge , install and seal these over the top and bottom exterior joints. Helpful Resources : Run a continuous bead of 100% silicone

: If your windows have nailing fins or J-channels on the sides being mulled, remove them using pliers or a utility knife to allow the frames to sit tightly together.