Exterior French Doors: How a Pair Works, Seals and Compares With Sliding Doors

Exterior French doors are a pair of hinged doors, each with a big panel of glass, that open onto a deck, patio or yard. They open the whole width of the doorway and bring in light, and they look right on many Ontario homes. A pair is also more than two doors side by side. This guide covers how the parts work together, where a pair can leak, what sizes to plan for, and how French doors compare with sliding patio doors.

We are EHI Custom Doors. We manufacture and install custom fiberglass back doors and front doors, including French-style pairs, from our workshop in Whitchurch-Stouffville. We build hinged doors, not sliding ones, so we will be clear about where a slider is the better choice.

What Exterior French Doors Are

The name comes from a traditional look: two hinged leaves with tall glass panels, often divided into small panes called lites. Most people use it for any pair of hinged glass doors. Our catalogue lists this style as patio door models, 6 feet 8 inches tall, in a 10-light pattern, a 15-light pattern and full-length glass, and some models show blinds sealed between the glass panes for privacy you can adjust. Our guide to exterior door glass options covers the glass, so this guide covers everything else.

How a Pair of Doors Works

With one door, the lock and the seal are simple. With two, you have a gap down the middle to deal with, and one leaf that has to hold still without a lock of its own. Most pairs solve this the same way.

Framewell explains the meeting strip, called an astragal: it closes the clearance gap between the leaves, holds the weatherstripping and end seals, and can house the bolts and the strike for the lock. That one strip does three jobs, which is why it deserves a close look on any pair of doors you are thinking of buying.

French Doors vs Sliding Patio Doors

Andersen makes the same trade-off: in a larger space the double opening of a hinged door lets in lots of fresh air and eases the flow between indoors and out, while in a small space a sliding door saves room by opening flush with the wall. Sliders also suit a modern style and hinged doors a traditional one. If you have a shallow deck, a narrow yard or a wall of glass in mind, a slider may be the better choice, and we would rather say so than sell you a pair that will not fit your space. If you want the wide opening, the traditional look and a door that we can build to your exact size, French doors are the answer.

Swing Space and Floor Plan

Each leaf swings in an arc about as wide as the leaf itself, so a pair needs clear floor on the side it opens to. Inswing pairs need room inside for furniture and rugs. Outswing pairs need room on the deck for chairs and planters. In an Ontario winter, snow and ice on a deck can block an outswing pair, so think about who will clear it. Our back door replacement guide has a table that compares inswing and outswing, and covers the Ontario Building Code rule for a single dwelling.

Sizes and the Rough Opening

Most doors in our catalogue are 32, 34 or 36 inches wide per leaf, so a pair spans roughly 5 and a half to 6 feet of door before the frame is added. Our patio door models are 6 feet 8 inches tall. We build to your measured opening, not to a stock size, so the numbers above are a guide and not a limit. Many existing sliders are about 5 or 6 feet wide, which is close to what a pair of French doors needs.

1. Photograph the doorway from inside and outside, with the whole frame in view.
2. Measure the width and height of the opening at more than one point.
3. Note which way the door opens now, and what is on both sides of it.
4. Note the height of the deck or step outside compared with the floor inside.
5. Send the photos and numbers with your quote request.

Our notes on Toronto permit and heritage rules explain the permit rule, and our guide to converting a window to a door covers the bigger job. After you approve a quote, our installer takes the final measurements at your home before we build.

Sealing, the Sill and Water

A pair has more edges to seal than a single door: two leaves, a centre seam and a wide threshold. That is fine when it is built and fitted well. Natural Resources Canada says a poorly installed product can cause cold drafts even when the product itself is energy efficient, so fit matters as much as the door. Our guide to energy efficient entry doors explains what to ask about air leakage.

• Check the centre seam for gaps and for daylight showing through when both leaves are shut.
• Make sure the inactive leaf does not rattle when the bolts are set.
• Look at the threshold. It should shed water away from the frame and sit well against the floor or deck.
• Ask how the sill is flashed and sealed during installation, since a wide sill is where water gets in.
• Watch for a deck or patio that slopes toward the door.

Water is the big reason to choose fiberglass for a pair of doors. A wood frame and sill can soak up water and rot at the bottom, where doors sit in rain and snow. Our slab, frame and brickmould are solid composite fiberglass, so no part of the set rots. Our guide to the advantages of fiberglass doors covers the construction.

Security for a Pair

A pair is only as strong as its inactive leaf and its centre seam. Look for bolts that go into the head and the sill, a lock on the active leaf that is well matched to the frame, and, if you want extra strength, a multipoint lock, which locks the door at several points along its height. Lock type is one of the things that changes the price, so ask for it on your quote. Glass near the handle is the weak point of any glass door, so ask about glass placement and laminated glass. Our guide to front door security covers the frame, the strike plate and the hinges.

Finish, Hardware and Matching

French doors are seen from the yard, the deck and the kitchen, so the finish counts twice. Choose the same finish family as your front door so the house reads as one. Our guides to matching front and back doors and wood grain fiberglass doors show how to do it, and our front door hardware guide covers the metal finish. If you would like a pair at the front of the house, see our guide to single vs double entry doors.

What French Doors Cost

A French-style pair is a double door, and at EHI Custom Doors a custom fiberglass double door starts at $5,100 installed. The final price moves with the glass style, the lock type, the finish, the size and whether the frame needs replacing. Our guide to custom exterior doors cost in Toronto explains each factor, and asking for the same lock on both quotes is the fairest way to compare.

Mistakes to Avoid

• Ordering a pair without checking the swing space on the deck or in the room
• Forgetting the height difference between the deck and the floor
• Ignoring the inactive leaf's bolts and the centre seal
• Choosing clear glass without thinking about who can see in
• Assuming a wider opening is a simple swap

Get a Quote for French Doors

Browse the door catalogue and photos of doors we have installed, then send photos of your doorway and the deck outside it. Call EHI Custom Doors at 647-952-2311 or request a quote. We are open Monday to Sunday, 9 AM to 5 PM, and there is no pressure to book on the spot. Read what customers say on our reviews page.

Exterior French doors give you the widest opening and the most traditional look, as long as you have the room for the swing. Get the meeting edge, the bolts and the threshold right, and a pair will feel solid and stay dry for years.