Short answer. For the specifically listed right-handed inswing Therma-Tru astragal, the manufacturer's store describes an astragal mounted to the passive leaf and secured with shootbolts. source The 2017 HYBRID astragal guidance likewise identifies the door slab intended to be fixed as the attachment location. source The meeting-stile question therefore begins with which leaf carries the astragal, not with replacing whichever trim piece looks worn. Edition limit: the 2017 HYBRID Shop 3 astragal installation instructions on p.3.47 are explicitly limited to French and two-sidelite French variants using a wide patio mullion. They are not a generic double-door assembly rule.
Distinguish hardware from trim at the meeting stile
The illustrated 2017 HYBRID aluminum astragal includes a snap-in cover, strike plate and deadbolt plate as separately identified items. source The Project Center replacement instructions also discuss taking off astragal snap-in trim before servicing other components and distinguish later strike-plate steps. source A removed cover is not by itself proof that the sealing material is missing.
| What you see | Record | Avoid concluding |
|---|---|---|
| Vertical member mounted on the less-used/passive leaf | Astragal body candidate source | Any other handing of astragal fits it. |
| Removable-looking facing next to strike hardware | Snap-in cover candidate source | Decorative/trim cover is the compression gasket. |
| Strike or deadbolt hardware at center edge | Hardware-reference candidate source | An arbitrary gasket can be mounted across those openings. |
| Small pad at a seal endpoint | Corner-pad candidate; inswing rule may apply source | Every paired-door arrangement uses the same pad. |
Safe identification before parts ordering
- Photograph both complete doors closed, with the meeting stile clearly visible. Label which leaf is normally opened, which appears fixed/passive, and which side has hinges.
- Take separate photos of the upper and lower ends of the center member, the latch/strike zone and any visible flexible strip. Do not remove the member or operate shootbolt parts forcibly.
- Confirm whether the installed system is among the wide-patio-mullion French configurations specifically listed on 2017 HYBRID Shop 3 p.3.47 before applying those drawings. The illustrated fixed slab and separate cover/plates must not be generalized to other paired-door systems. source
- If considering a local pad, note that the 2017 coastal astragal page limits its pictured corner pads to inswing units. source Do not carry that statement to every outswing or later revision.
- Stop if the door is insecure, bolts do not engage, the documentation cannot identify the frame/leaf, or a fire/smoke-rated assembly is involved. Request the exact assembly instructions or qualified evaluation.
Result categories
Body identified, cover undetermined: ask for the matching astragal trim/hardware list. Evidence of a flexible seal but unclear profile: seek the specific part drawing; do not substitute a cover SKU or universal tape. Uncertain leaf or handing: no item selection. The manufacturer pages establish component identities and edition-specific assembly relationships, not a current cross-model compatibility chart.
Primary sources and claim locator register
- — Therma-Tru original, US HTML product listing, accessed 2026-10-11; Right handed Inswing product listing, passive door/shootbolts bullet. Publisher document.
- — Therma-Tru original, 2017 Shop Manual HYBRID — Shop 3; HYBRID Shop 3 p.3.47, fixed slab instruction. Publisher document.
- — Therma-Tru original, 2017 Shop Manual HYBRID — Shop 3; HYBRID Shop 3 p.3.48, labels for snap-in cover, strike, deadbolt plate. Publisher document.
- — Therma-Tru original, 2017 Shop Manual HYBRID — Shop 3; HYBRID Shop 3 p.3.49, coastal astragal inswing caution. Publisher document.
- — Therma-Tru original, US HTML undated, accessed 2026-10-11; Project Center Steps 1–7, snap-in trim and strike components. Publisher document.
Evidence and safety boundary
Therma-Tru’s 2017 Hybrid Shop Manual, Shop 3 (printed pp. 3.47–3.49) illustrates several components at the meeting edge of paired doors. Separate the astragal body, cover, hardware and flexible contact seal when recording the visible defect. Photograph the meeting stile and mark which leaf is active before contacting the manufacturer. A trim/cover part number does not automatically identify a replacement gasket.