Vinyl siding installation requires a variety of special strips and channels that are designed to secure the siding panels to house walls and capture the cut ends of vinyl siding. These include corner posts, starter strips, J-channels, and similar attachment and trim pieces.

Vinyl Siding Channels & Trim

Most vinyl siding manufacturers make two or three sizes of J-channels. For vertical siding, these channels typically have openings of 3/8 inch to 1/2 inch to receive siding panels and soffit materials. For horizontal siding, J-channels with openings of 3/4 inch to 1 inch are commonly used. When ordering these channels, be sure to match them to the siding pattern to ensure a snug, weatherproof fit.

Other trim and moldings used to accessorize and mount vinyl siding include starter strips, F-channels, drip caps, inserts, and trim. They are designed to give every installation a professional, finished appearance and make all joints weather-resistant.

Vinyl Siding Corner Posts

When vinyl siding is installed on a house, special vinyl corner post pieces are utilized to provide weather-resistant, good-looking joints at both inside and outside corners. They are made from solid vinyl, just like the siding, and produced in the same colors as the siding. Here is a closer look at both types:

Inside Corner Post
At inside corners of a wall, where vinyl siding meets from two adjoining walls, this accessory is used to provide a weather-resistant joint. The siding fits neatly in the channels extruded along the length of these posts. These corner posts are manufactured in a variety of sizes to accommodate all types and configurations of siding. Note: In some cases, two J-channels, installed with corners together, substitute for an inside corner post.

Outside Corner Post
These corner posts are designed to provide a neat, weather-resistant outside corner on house walls. These, like inside corner posts, have channels for receiving the siding and come in appropriate widths for all types of vinyl siding.