Use this guide to resolve the pair and transom details before work begins. Find the door installation instructions for your exact unit and use them to set the installation sequence, fasteners and clearances.
Interior and exterior pairs need different plans
| Detail | Interior opening | Exterior opening |
|---|---|---|
| Floor or sill | Finished floor, rugs and permitted bottom gaps. | Supported threshold, water management and landing relationship. |
| Frame-to-wall connection | Support, alignment and finish trim. | Support plus flashing, exterior joints and an interior air seal. |
| Meeting edges | The latch, catches or bolts specified for the pair. | Compatible locks, seals and any overlapping astragal. |
| Glass | Privacy and any applicable safety-glazing needs. | Safety glazing, privacy and required energy or exposure performance. |
Browse French door designs by location and function. A French-style sliding barn door has a different mounting system from a hinged pair.
Name the active leaf and draw the swing
The active leaf is the one intended for regular passage when the design uses an active and inactive pair. The inactive leaf may be held by top and bottom bolts, depending on the assembly. Some pairs use a different arrangement, so confirm it on the order rather than assuming both panels operate the same way.
On a simple plan, label the rooms, hinge sides and opening arcs. Use the supplier’s handing chart and the door swing planning guide together. Check furniture, light switches, curtains and the space behind both handles.
If an astragal overlaps the meeting edge, it can determine which leaf closes first. That sequence affects the lock and seal arrangement. Get it settled before hardware holes are prepared.
Check three alignment relationships
First, the head should remain straight and the hinge jambs properly aligned. Second, the meeting edges must work together without one leaf striking or pushing the other out of position. Third, both leaves must clear the floor or sill through their intended movement.
Matching-looking gaps are useful, but they do not replace level, plumb and square checks. Use the exact unit’s tolerances and shim locations. The frame must stay supported while the specified anchors are installed; decorative casing is not structural attachment.
Reference: Example hinged-patio-door guide with product-specific support and alignment checks.
Measure the entire unit, including a transom
Record the rough opening separately from the overall unit size and individual leaf sizes. Include the frame, sill if present, and any planned transom or sidelights. Check the available wall depth and finished floor level.
A transom changes the full assembly height and the support needed above the doors. Have the framing reviewed before removing a header or enlarging an opening. The space over a pair is not automatically free space that can be filled with a homemade window.
The transom window design guide shows ways to compose the opening. Ask the supplier how the transom connects to the door frame and how the combined assembly is supported.
Specify the glass before building the transom
Use a glazing specification appropriate to the location, dimensions, support and applicable safety requirements. Have the supplier confirm glass type, thickness, edge support and retention. A generic thickness or a single distance from the door is not enough to specify every transom.
Order tempered glass to its final required dimensions; it cannot be field-cut like ordinary annealed glass. Do not plan to build a frame first and trim a tempered pane to fit afterward. For an exterior transom, include its drainage, seals and thermal requirements with the rest of the entry.
Reference: Guardian Glass processing guidance on heat-treated glass.
Check operation before covering the frame
- Both leaves move freely through their intended swing.
- The active and inactive leaves close in the correct sequence.
- Bolts, latch and lock engage without lifting or forcing either leaf.
- Meeting-edge seals and perimeter seals contact as specified.
- The finished floor and any sill do not cause rubbing.
- The transom and surrounding frame are supported as designed.
If the pair binds, diagnose the frame and hardware first. The door installation troubleshooting guide explains why trimming a leaf or moving a strike is not always the first repair.
Prepare a complete quote request
Send a dimensioned opening sketch, the desired swing, the active leaf, photos of both sides and the finished floor height. Include the transom, privacy glass, lock function and any exterior exposure. A complete description helps the supplier identify which parts belong in the order before installation begins.
Planning a client project?
Specifying a French door pair for a client? Keep the approved opening sketch with the hardware and glass selections. Rustica’s contractor discount program explains professional eligibility and how to apply.
