When installing soffit on a gable roof, there are a few things you should keep in mind. First, be aware of the increased safety concerns, as the gable is higher than a horizontal overhang. Second, take care when cutting the soffit to ensure a neat, professional finish. While both soffit and fascia are relatively easy to install, the hardest part is ensuring crisp junctures at corners and at the top of the eave. With this in mind and proper measuring, installing soffit on your gable roof will be a breeze!

Understanding the Necessary Components and Materials


This is the finish material that will be exposed when you look at the eaves. It can be wood, vinyl, composite or aluminum. Depending upon your ventilation needs, the pieces can be solid, perforated, or a combination of both. For hidden soffit venting, Rollex offers Stealth Soffit for the best of both.


As the name implies, J-channel is a trim piece made from vinyl or aluminum in the form of a "J" that secures the soffit to the exterior of the home. The J channel is installed on the exterior wall of the home where the soffit panels will be inserted and then nailed to the end of the fascia board.

Fascia and Fascia Board

Fascia board is the outermost part of the home on the gable end or eave of a home. On the gable end, it is often referred to as a rake board. For most applications, the fascia board will be covered with a sheet of fascia to match the soffit underneath the eave. This provides aesthetically-pleasing weatherproofing with virtually no maintenance.

Drip Edge

A drip edge is installed on the edge of the roof sheathing at the eaves and gable ends where the fascia board meets the roof. It serves three purposes:

  1. It protects the edge of the plywood or OSB from being damaged or absorbing moisture
  2. It provides support for the shingles to keep them straight as they hang over the edge of the roof
  3. It holds the top of the fascia cover in place.

Preparations for Install

1. Safety Equipment and Gloves for Handling Aluminum

Installing soffit on gable ends can be a DIY project if you are comfortable working off the ground. The tools required for this job are simple, and you may have most of them already:

  • Heavy gloves to handle sharp edges of aluminum soffit panels
  • Safety glasses
  • Tin snips or aviator snips
  • Trim nail punch
  • Ladder
  • Speed square/Combination square for drawing straight lines
  • Hammer, utility knife, tape measure and chalk line
  • Hand-held folding/hemming tool for making small bends in soffit and fascia and J-channel

TIP: Planning to install soffit on a second-story gable end? To avoid injury or project complications, consider renting scaffolding or hiring a professional.

2. Measure the Width and Length of the Sub Fascia for the Soffit and J-Channel

The sub fascia is the area of rough framing extending beyond the exterior wall you will be installing the soffit and J-channel against. The height of the sub-fascia should be measured. The distance from the wall to the outer eave board is known as the underside of the eave. The overhang may range from 12 inches (30 cm) to 24 inches (60 cm), although your house's dimensions may vary somewhat.

3. Cut Soffit and J-Channel to Measurements

Soffit and J-channel are generally sold in 12' lengths. Pre-cut the number of pieces needed for the soffit while on the ground. Remember, gable end and eave soffit will be installed perpendicular to the way it is sold.

Soffit and Fascia Installation Steps and Tips

1. Install the Drip Edge

If not already present from the home’s construction, the drip edge is installed on top of the roof felt and below the shingles. If the shingles have been installed before the drip edge was in place, slide the drip edge under them and place a few nails through the top of the drip edge every couple of feet. The bottom of the drip edge will go over the aluminum fascia and hold it in place.

2. Install J-Channel Along the Sub Fascia

Position the J channel on the underside of soffit framing and fasten using staples or nails at 16” intervals. Using this method, the open end of the soffit is covered by pre-bent fascia at the end of the installation.

When working at the gable, the J-channel should be cut at 45-degree angles, where it ends at the top and bottom of the gable for a professional finish.

TIP: Use staples or nails to secure the J-channel. Spend extra time on corners, as they are some of the spaces most often viewed, and they require the most precision to perfect.

2. Install Soffit Panels

The measured and cut soffit panels will slide into the J-channel and are then nailed to the fascia board to hold them in place. Make sure to nail through the flange or grooves only.

When complete, take the next panel and insert its tongue into the flange of the previously installed panel. Continue this procedure for the length of the run.

TIP: Use a carpenter square for the first panel to verify it’s squared to the gable end eave. If not stapling, make sure to use 1” aluminum trim nails when attaching the panels to the fascia board.

3. Install Fascia

Purchase pre-bent fascia wide enough to cover the fascia board with a 90-degree bend at the bottom and a lip wide enough to cover the edge of the fascia board. Install the fascia by slipping it behind the drip edge, then nailing to the underside of the fascia board with pre-painted 1 ¼” aluminum trim nail spaced every 16-24”.

Once the nailing is finished, line up the lip of the gable fascia with the fascia board on the eave. Notch the lip so that the two points align. At the top of the gable, one side will overlap the other. Make sure you cut the overlapping piece so that the angle is aligned with the rafter angle.

Use the Best Aluminum Soffit and Roof Flashing from Rollex

At Rollex, we offer a beautiful, high-quality aluminum soffit and fascia that complements all types of siding including vinyl, stucco, brick and fiber cement. Our soffit is almost entirely maintenance-free because it has a baked-on finish that provides a long-lasting, dirt-resistant finish.

Our soffit comes in various colors, so you're sure to find the right one that complements your home's exterior. As an added benefit, our aluminum soffit can be recycled repeatedly, ensuring it is ecologically responsible. With our industry-leading guarantee and unrivaled durability, you can be certain that you're receiving the finest quality material for your home. Contact us today for more information.