French doors are beautiful. Two panels swing open to create a wide, welcoming entry. But that double‑door design also creates a double‑sized problem when it comes to weather protection.
A single storm door won’t cover both panels. One door would remain exposed to rain, wind, and UV damage. The solution is a double storm door system: two matching storm doors, one for each leaf, that work together as a single protective barrier.
Double storm doors are more complex than single doors. The center meeting point (astragal) must seal tightly. The frames must align perfectly. And the entire assembly must handle wind loads across a wider span without sagging.
This guide covers everything you need to know: astragal design, aluminum frame requirements, installation challenges, and which configurations work best for French doors.
Why French Doors Need Double Storm Protection
French doors have two independently swinging panels. The active leaf (with handles and lock) opens frequently. The inactive leaf (with top and bottom bolts) opens only when you want the full width.
Without storm doors:
- Rain drives into the center gap between the two doors
- Wind pressure pushes both panels inward, stressing the lock
- UV fades the finish on both leaves unevenly
- The inactive leaf’s bolts can freeze or corrode
A single wide storm door won’t work because it would have to swing outward and block the French door handles. The only practical solution is a pair of storm doors: one for each leaf.
For a foundational understanding of storm door protection, see our what do storm doors do for a home guide.
The Critical Component: The Astragal
The astragal is the vertical profile where the two storm doors meet. It’s the most important—and most failure‑prone—part of a double storm door system.
What an astragal does:
- Seals the gap between the two storm doors
- Provides a locking point for the inactive leaf
- Transfers wind loads from one door to the other
- Prevents water from driving through the center seam
Astragal types:
| Type | How It Works | Best For |
|---|---|---|
| T‑astragal | Attached to one door, overlaps the other | Standard double doors, moderate wind |
| Z‑astragal | Interlocking shape, both doors contribute to seal | High wind, security applications |
| Removable | Pinned or bolted, allows both doors to open fully | When you occasionally need full width |
Material matters: Extruded aluminum astragals are far superior to vinyl or plastic. Aluminum won’t bow, crack, or deteriorate in UV. It accepts the same powder‑coated or anodized finish as the rest of the door.
For homeowners with security concerns, an aluminum Z‑astragal with multi‑point locking provides excellent resistance against spreading the two doors apart. See our best security storm doors guide for more on forced entry resistance.
Frame Strength: Double Doors Need Heavier Aluminum
A single 36‑inch storm door has a relatively compact frame. Two 32‑inch doors side by side create a 64‑inch wide assembly. Wind pressure on that larger surface area is significantly higher.
Minimum specifications for double storm doors:
- Extruded aluminum – Not rolled or stamped
- Alloy – 6063‑T5 or stronger
- Wall thickness – 0.080 inches minimum (0.100 preferred)
- Profile depth – 65mm or more
- Header – One continuous piece across both doors (not two separate headers)
Cheaper double storm door systems use two independent doors with a thin vinyl astragal. The frames flex independently, the astragal leaks, and the whole assembly rattles in wind.
Premium systems use a reinforced header that ties both doors together structurally. The astragal is integral to one door’s frame extrusion, not an add‑on.
Hinge and Hardware Considerations
A French door storm system has twice the hardware of a single door. That’s double the potential failure points.
Hinges:
- Each door needs three heavy‑duty hinges (six total)
- All hinges should have stainless steel pins
- Consider continuous (piano) hinges for the inactive leaf—stronger and more stable
Latching:
- Active leaf has a standard storm door handle and deadbolt
- Inactive leaf needs flush bolts (top and bottom) that engage into the header and threshold
- The astragal should include a keeper for the active leaf’s latch
Closers:
- Each door needs a pneumatic closer
- Closers must be synchronized so both doors close at the same speed
- Adjustable closers are strongly recommended
For a baseline understanding of hinge quality, see our aluminum screen vs. storm doors comparison which covers structural differences.
Matching Aesthetics: Both Doors Must Look Identical
French doors are symmetrical by design. The storm doors should be too.
- Same frame finish – Both doors from the same batch, same powder‑coated or anodized color
- Same glass type – Both with Low‑E, both clear, both tinted
- Same screen system – Retractable or interchangeable, identical
- Mirrored hardware – Handles on the active leaf; flush bolts on the inactive leaf should match the handle finish
- Continuous sightlines – The astragal should be barely visible, not a thick protruding seam
For modern homes, full‑view glass with retractable screens and matte black finish creates a clean, uninterrupted facade. See our best full view storm doors for modern homes guide.
Installation: Why Professional Help Is Worth It
A single storm door installation is DIY‑able. A double storm door system is not.
Installation challenges unique to double doors:
- Absolute level alignment – Both headers must be perfectly level with each other. A 1/8‑inch height difference means the astragal won’t seal.
- Plumb jambs – Both side jambs must be exactly vertical. If one leans, the doors won’t meet correctly at the center.
- Threshold flatness – The bottom sweep on both doors must contact the threshold evenly across 64+ inches.
- Header reinforcement – The continuous header needs backing inside the wall. Mobile home or thin‑stud construction may require blocking.
- Closer synchronization – If one closer is faster than the other, the doors will slam out of sequence and stress the astragal.
Estimated professional installation cost: $300–500 for a double system (vs. $150 for a single door). Worth every dollar.
When Double Storm Doors Don’t Make Sense
Narrow French doors (under 60 inches total width): A single extra‑wide storm door (60–72 inches) may be available. Fewer moving parts, simpler installation.
Inswing French doors (open inward): Standard storm doors mount externally and swing outward. Inswing primary doors with outswing storm doors work fine—just check handle clearance.
Extreme weather exposure: In hurricane zones, impact‑rated French doors with integrated storm protection may be required by code. Double storm doors alone may not meet wind‑borne debris requirements.
Budget constraints: A quality double storm door system costs $1,000–2,500 installed. If that’s prohibitive, consider protecting only the active leaf with a single storm door and accepting that the inactive leaf will weather faster.
Top Configurations for Different Needs
| Use Case | Recommended Configuration |
|---|---|
| Coastal home, high wind | 6063‑T5 aluminum, 0.100″ wall, Z‑astragal, 316 stainless hardware, anodized finish |
| Modern farmhouse | Full‑view glass, retractable screens, matte black finish, T‑astragal |
| High security | Security mesh (not glass), multi‑point locking astragal, hidden hinges |
| Cold climate (MN, WI, NY) | Low‑E glass, thermal break frames, dual‑fin weatherstripping |
| Hot‑humid (FL, TX) | Ventilating (glass top, screen bottom), anodized finish, anti‑sag header |
For a complete list of climate‑specific recommendations, see our storm doors necessary by climate guide.
Leading Brands Offering Double Storm Door Systems
- Larson – Offers double door configurations in select series (Tradewinds, Premium)
- Andersen – Custom double systems, premium extruded aluminum
- ProVia – Heavy‑duty, excellent astragal design, made‑to‑order
- EMCO – Good mid‑range double door options
Always verify that the double system uses a continuous header and an extruded aluminum astragal. If the spec sheet says “vinyl astragal” or “two separate units,” keep looking.
The Bottom Line
Double storm doors are a specialty product. They cost more, require professional installation, and demand higher material specifications than single doors. But for homes with French doors, they are the only way to protect both panels equally and preserve the symmetrical aesthetic.
Your checklist:
- Extruded aluminum frames, 0.080″ wall minimum
- Continuous header (not two separate units)
- Extruded aluminum astragal (Z‑style for high wind)
- Six heavy‑duty hinges (three per door)
- Matching finishes, glass, and hardware
- Professional installation for alignment
- Budget $1,000–2,500 installed
Skip cheap double systems with vinyl astragals and thin frames. They’ll leak air, sag within years, and ruin the clean look of your French doors. Invest in quality extruded aluminum engineering once.
For a starting point, see our best aluminum storm doors for front entrances buyer’s guide and filter for double‑door configurations.
