A very small section of extruded plastic J-channel.
J Channel is a building material that is usually made out of vinyl or plastics. Sometimes it can be made out of metals such as aluminum or tin, but these days that is getting rare.
There are many uses for J-Channel. It can be used to hold ceiling panels in place, used as a drip edge for areas that you want to keep dry, and in extreme cases, can be used as bottom tracking for mobile home skirting.
The most extensive use of J-Channel is for trimming vinyl siding around doors and windows. This use is not just for mobile homes and it can be used on just about any building structure.
The Bad Part
Oh yeah, this stuff is great. When used properly, it can make a window look good or correct how a crooked door looks. It basically covers up builders mistakes. But there are just some mistakes that J-Channel cannot cover up. Addtionally, there are mistakes that can be made with J-Channel that can drastically damage the home that it is installed on.
Example Of A Mistake
Front view facing door frame. This is where J-Channel is installed around a doorway. It is used as molding to cover the cut ends of vinyl siding.
Side view showing cross section of door frame, siding, and J-Channel. This is a common mistake made with J-Channel on a doorway. The home's siding does not meet and cover the J-Channel. This leaves a gap that will lead to water getting into the door frame, causing damage to the home.
Side view showing cross section of door frame, siding, and J-Channel. The home's siding is cut too short. Water can get behind the siding and the door frame. This causes structural damage.
Side view showing cross section of door frame, siding, and J-Channel. This J-Channel is incorrectly installed as the siding is tucked
behind the J-Channel.
Side view showing cross section of door frame, siding, and J-Channel. When vinyl siding is incorrectly tucked behind J-Channel, it creates a gap that water can collect on and leak into. This causes damage to the door frame.
