Larson Patio Storm Door

The Larson Patio Storm Door creates a secondary thermal barrier over existing sliding glass doors, available in two standard sizes with customizable glass options. This discontinued product offers measurable energy savings by reducing heat loss in winter and heat build-up in summer. For Montana contractors dealing with temperature swings from -40°F to 100°F+, it addresses the specific challenge of older patio doors that leak air and waste energy.

Energy Performance & Installation Specs

The door acts as a secondary thermal barrier, creating an insulating air space between itself and the primary sliding door. Glass options include standard clear tempered or optional Low-E coating for enhanced energy efficiency. Contractors can specify glass thickness in three options: 1/8” (standard), 5/32”, or 3/16”.

The nail fin mounting system installs directly over existing door frames on the home’s exterior. No tear-out required. Two standard sizes accommodate most residential applications: 71-1/4” x 79-3/4” (for 6’0” x 6’8” openings) and 73-1/4” x 81-3/8” (for 6’0” x 6’10” openings), both measured tip-to-tip with the 3/4” nail fin.

Specification	Options
Standard Sizes	71-1/4” x 79-3/4”, 73-1/4” x 81-3/8”
Glass Types	Clear Tempered, Low-E
Glass Thickness	1/8”, 5/32”, 3/16”
Frame Material	Heavy-duty aluminum
Finishes	White, Brown
Mounting	Nail fin over existing frame

Installation requires basic tools: drill, level, screwdriver, measuring tape, and caulk. The process follows a straightforward sequence: measure the opening, apply sealant to the nail fin back, position over existing door, secure through the fin into exterior casing, and verify track levelness.

Configuration Flexibility

The reversible design fits either left- or right-active sliding doors without special ordering. Custom configurations extend beyond the two standard sizes to accommodate 2- or 3-panel sliding door units. Installation requires sufficient exterior trim or casing width for proper nail fin attachment.

Customer feedback highlights significant reduction in drafts and noise, with users specifically noting the door keeps interior glass warm during winter. The reversibility proves valuable for different door layouts. Some installations on non-standard older homes encountered difficulty finding exact custom sizes.

The Bottom Line

This storm door delivers on its core promise: reducing heat loss in winter and heat gain in summer through a secondary barrier system. The heavy-duty aluminum frame construction with tempered safety glass provides durability. While discontinued as of December 2022, existing installations continue performing well, and the specifications remain relevant for maintenance or matching existing systems.

For Montana’s extreme temperature differentials, the optional Low-E glass makes the most sense. The secondary air barrier addresses the primary weakness of older sliding doors — continuous air infiltration that no amount of weatherstripping can fully solve. At 70°F inside and -20°F outside, that trapped air space between doors becomes valuable insulation.

FAQ

What warranty coverage did Larson provide for patio storm doors?

Larson typically offered a Limited Lifetime Warranty on storm door frames, with components like hardware and seals carrying 1, 5, or 10-year limited coverage. Modifying the door during installation could void warranty protection.

Can these doors be installed on any sliding patio door system?

The doors work with standard 2-panel sliding systems and offer custom configurations for 3-panel units. The key requirement is sufficient exterior trim or casing width to accommodate the nail fin attachment method.

How much energy savings can homeowners expect?

While storm doors themselves aren’t typically Energy Star rated as standalone units, the optional Low-E glass contributes to energy savings. Users report noticeable draft reduction and warmer interior glass temperatures during winter.