Woodgrain Smooth-Star 1 Lite Exterior Transom (PRM)

The Smooth-Star 1 Lite Exterior Transom delivers a budget-friendly fiberglass solution with polyurethane foam core insulation and a ready-to-paint smooth surface. This transom is Therma-Tru’s entry-level option, distributed by Woodgrain, offering a Limited Lifetime Warranty for residential installations. At standard widths from 1’6” to 3’6” plus custom options, and heights of 6’8”, 7’0”, or 8’0”, it fits most residential entry configurations.

The transom’s design incorporates compression weatherstripping for tight sealing and earns ENERGY STAR qualification with most glass options. For Montana’s temperature extremes, that weatherstripping detail matters as much as the foam core.

Energy Performance & Glass Options

The polyurethane foam core provides the thermal break, while NFRC-certified ratings back up the energy claims. Glass options include Clear, Low-E, Satin Etch, and decorative configurations, all factory-installed. The glass carries a 10-20 year warranty against seal failure, depending on the specific package selected.

Available in both 1 3/8” and 1 3/4” thickness options, the transom adapts to different door system requirements. The thicker option provides better thermal performance for extreme climate installations.

Specification	Value
Glass Options	Clear, Low-E, Satin Etch, Decorative
Thickness Options	1 3/8”, 1 3/4”
Glass Warranty	10-20 years (seal failure)
Energy Rating	ENERGY STAR Qualified (most options)
Certification	NFRC Certified

Installation Requirements & Compatibility

The transom requires a transom head or mullion for structural support and comes designed for prehung installation above a door unit. The PRM designation means the frame arrives primed and ready for a finish coat of paint. Woodgrain recommends high-quality exterior-grade paint for the final coating.

Compatible with all Smooth-Star series doors and matching sidelites, the transom creates a cohesive entry system. Standard door unit widths like 3-0 and 2-8 accept the transom without modification.

The package includes the 1 lite glass (factory installed), primed wood or composite frame, optional exterior brickmould per SKU, and all glazing and weather-seals. The moisture-resistant composite or primed wood frame options address Montana’s freeze-thaw cycling concerns.

Market Position & Trade-offs

Positioned as a budget-friendly alternative to wood or high-end fiberglass, the Smooth-Star competes against Fiber-Classic’s woodgrain texture options and Classic-Craft’s premium fiberglass with deeper grains and thicker skin. Steel transoms cost less upfront but dent more easily and deliver inferior energy performance compared to the Smooth-Star’s fiberglass construction.

The smooth, ready-to-paint fiberglass surface eliminates priming steps on the slab itself. Customer feedback indicates this smooth surface simplifies painting compared to textured doors, though some buyers report long lead times for custom units and concerns about glass replacement costs outside warranty coverage.

FAQ

What sizes does the Smooth-Star transom come in? Standard widths include 1’6”, 2’0”, 2’4”, 2’6”, and 3’6”, with custom sizing available. Heights come in 6’8”, 7’0”, and 8’0” options.

Does the transom require structural support? Yes, the transom requires either a transom head or mullion for proper structural support when installed above a door unit.

What’s included with the transom? The package includes factory-installed 1 lite glass, a primed wood or composite frame, glazing and weather-seals, and optional exterior brickmould depending on the SKU.

How does it compare to steel transoms? The fiberglass Smooth-Star resists denting better than steel options and provides superior energy efficiency through its polyurethane foam core.

What warranty coverage does it carry? Therma-Tru provides a Limited Lifetime Warranty for residential applications, covering the fiberglass slab against warping and delamination. Glass seal failure coverage runs 10-20 years depending on the specific glass package.