Undersill

The Vinyl Undersill Trim is an essential finishing piece for any professional siding job. Installed beneath windows, along the top row of siding, or under soffits, it locks cut panels securely in place where a full panel won’t fit.

Made from high-quality, UV-resistant vinyl, this trim ensures a tight, clean fit while allowing natural expansion and contraction. It’s virtually invisible once installed — but it makes all the difference in the durability and polish of your siding work.

Size : 12.5ft

Perfect for: Top-of-wall terminations, window headers, gable peaks, and finishing cut siding panels.
Category: Siding