Mastic Trim Coil: Colors, Sizes and Matching Siding

Bare wood fascia and window casings are where most siding jobs start to fail, and aluminum capping is the usual fix. Mastic trim coil is the coated aluminum sheet, sold in rolls, that installers bend on a brake to wrap fascia boards, window and door trim, rake boards and porch beams so they match Mastic vinyl siding. The standard roll is 24 inches wide by 50 feet long, with a nominal thickness of 0.019 inch (often called 19 mil), and it comes in a PVC-coated woodgrain finish and a smooth painted finish.

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Mastic is a siding brand within the Ply Gem family, and the trim coil is listed through Ply Gem’s metals line with a color guide built to match Mastic siding colors. Picking the right coil comes down to finish, color match and availability in your region. The specs here come from the manufacturer’s trim coil documentation and dealer listings; check the current color guide before ordering, because the palette changes.

Mastic Trim Coil Specs at a Glance

PVC-Coated vs Smooth Painted Coil

The PVC-coated coil is aluminum covered with a thick vinyl layer that is striated during manufacturing to create a woodgrain texture. That texture blends with woodgrain vinyl siding and hides small scuffs and oil-canning (the wavy look flat metal sometimes shows). Because the coating is thicker, it also stands up better to ladder rubs and hail grit.

The smooth version uses the maker’s Alumalure 2000 paint finish and gives a flat, clean finish. It suits smooth-profile siding, modern exteriors and homes where crisp, sharp trim lines matter more than texture. Smooth finishes show dents and waves more readily, so careful handling and well-placed fasteners matter.

Both carry the same nominal 0.019-inch thickness and the same 24 by 50 roll size, so the choice is about appearance and color availability rather than strength. Some generic coils on the market run slightly thicker, around 0.021 inch, but a heavier coil is not automatically better if it does not match your siding.

Color Matching to Mastic Siding

The manufacturer publishes a trim coil color guide that maps each coil color to Mastic siding colors. Color names in that guide include Misty Shadow, Sage, Tuscan Olive, Russet Red, Woodland Green, Terra Cotta and Natural Slate, and dealer listings show coil colors such as White, Victorian Gray, Colonial Yellow and Evergreen. Some newer Mastic siding colors, such as Deep Cavern, may not have a dedicated coil match, so ask for the closest coordinating coil. Not every color is available in the PVC-coated finish, and the guide notes that additional colors are available through an extended lead time program.

Order by the coil model number, not just the color name. Dealer listings tie each color to a specific part number, and names can differ slightly between the guide and a store listing. Before committing to a full job, hold a sample of the coil against the actual siding on the house in daylight. Siding that has been up for ten years may have faded, and a “perfect” factory match can look a shade off next to it.

Matching tips

• Match the coil to the siding for a blended look, or to the windows for contrast trim.
• White and other neutrals are the most widely stocked; specialty colors may take weeks.
• Buy all coil for a job from the same lot so color is consistent.
• Order matching trim nails or color-matched screws for visible fasteners.

Tools and Materials

• Portable aluminum brake bender (8 to 10 feet long covers most fascia runs)
• Coil stand or a slitter attachment for cutting strips off the roll
• Aviation snips (left, right and straight cut)
• Hand seamer for hems and small bends
• Utility knife and straightedge for scoring
• Color-matched aluminum trim nails or stainless screws
• Exterior sealant rated for aluminum and vinyl
• Tape measure, square, chalk line, gloves and safety glasses

An aluminum brake bender is the tool that makes trim coil practical. Trying to bend long pieces by hand leaves wavy, kinked edges that never look right. Rental shops and siding suppliers often rent brakes by the day.

How to Wrap Fascia with Trim Coil

1. Prep the wood. Replace any soft or rotted fascia first. Capping over rot traps moisture and hides the problem until it spreads.
2. Measure the profile. Measure the fascia face height, the bottom return and any top lip that tucks under the drip edge. Add about 1/2 inch for a hem on the exposed edge.
3. Cut strips. Use a slitter or score and snap the coil to width. A 24-inch roll often yields three 8-inch strips or two 12-inch strips with little waste.
4. Hem the exposed edge. Fold a small hem on the visible bottom edge in the brake for a stiff, clean line.
5. Bend the profile. Make the main bends in the brake, working from the hem back. Check each bend against the fascia before continuing.
6. Install from the far end. Slide the top edge under the drip edge, then nail along the bottom return, not the face. Face nails show and invite dents.
7. Overlap joints. Overlap pieces about 1 to 2 inches, with laps facing away from the main view and downhill for water.
8. Leave room for expansion. Aluminum moves with temperature. Do not drive nails tight; leave them snug so the metal can slide.
9. Seal sparingly. Use sealant only at the points where water could enter, not along every seam.

Troubleshooting

Wavy face (oil-canning). Usually caused by tight nailing or no hem. Remove, re-hem and fasten through the return so the face floats.

Color looks off. Faded siding is the usual reason. Pick the next closest shade or switch to a deliberate contrast color for trim.

Scratches during install. Keep the protective side up on the brake and clean debris off the brake bed. PVC-coated coil hides light marks better than smooth.

Water behind the capping. Check that the top edge tucks under the drip edge and that laps shed water downhill.

General Cost Ranges

A 24-inch by 50-foot roll of coated aluminum trim coil commonly runs about $90 to $200, with PVC-coated and specialty colors toward the upper end. A small porch or garage door frame may need one roll; capping all fascia and windows on an average two-story house can take four to eight rolls. Professional trim wrapping often costs roughly $4 to $12 per linear foot installed, depending on profile complexity, height and region. Brake rental is typically a modest daily fee.

Ladder Safety and When to Hire a Pro

Most trim coil work happens at the roofline, so ladder safety matters as much as bending skill. Set the ladder on firm, level ground at roughly a 4-to-1 angle, extend it at least 3 feet past the landing point, keep three points of contact, and never overreach; move the ladder instead. Use ladder standoffs so you are not leaning on gutters, and work with a helper who can steady the ladder and hand up long pieces. Aluminum coil also conducts electricity, so keep ladders and long metal strips well away from service drops and power lines.

Hire a siding contractor for second-story fascia and rakes, homes with steep or high rooflines, or jobs where large amounts of rotten wood must be replaced first. Two or more stories call for scaffolding or lifts and fall protection, which a pro will already have. In homes built before 1978, painted trim being covered or removed should be tested for lead before scraping or sanding.