H-Jamb Shower Seal
Quick answer
An h-jamb seal is an H-shaped polycarbonate extrusion that caps the edge of a fixed glass panel and presents a soft flap or fin toward the door, closing the vertical gap between a swinging door and an inline panel (a 180° joint). One leg of the H grips the panel; the crossbar and flap bridge the gap. It is the standard cure for the "light saber" strip of spray escaping between door and panel.
Data reviewed:
What it is
On frameless door-plus-panel layouts, the door cannot touch the fixed panel or it would grind on every swing — so installers leave a 3/16–3/8 inch slot. The h-jamb mounts on the fixed panel (never on the swinging door), and its flexible fin overlaps the door edge, sealing the slot while the door sweeps past freely. Clear polycarbonate versions are nearly invisible.
Use it when
- Spray escapes through the vertical slot between the door and an inline fixed panel
- A previous h-jamb has yellowed, cracked at the flap root, or shrunk short
- You are converting a drafty panel joint to a sealed one without new hardware
What to measure
- Fixed panel glass thickness (the H channel grips the panel)
- Slot width between panel edge and door edge, top and bottom
- Panel height for trimming
Full walkthroughs: glass thickness · bottom gap.
Sizes in our reviewed catalog
| Glass range | Gap range | Lengths |
|---|---|---|
| 1/4″ | 3/16–1/2″ | 72″ |
| 3/8″ | 3/16–1/2″ | 72″ |
| 1/2″ | 3/16–1/2″ | 72″ |
Strengths
- Seals the door-to-panel slot without touching hardware
- Clear polycarbonate is almost invisible
- Door swing stays completely free
Limits
- Mounts on the panel only — will not work door-mounted
- Flap root is a stress point and eventually cracks
- Slots over ~1/2″ exceed standard fin reach
H-jamb seal options
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H-Jamb Shower Seal for Inline Fixed Panel, 1/4 in Panel Glass, 72 in
- Glass
- 1/4″
- Gap
- 3/16–1/2″
- Length
- 72″
- Material
- Clear polycarbonate with soft fin
- Mount
- press-on
- Trim
- Cut to size
Mounts on the FIXED panel; the long fin overlaps the swinging door across the slot. Sized to the panel's glass, which can differ from the door's.
⚠ Never mount an h-jamb on the swinging door — it will rake the panel edge and tear its fin.
H-Jamb Shower Seal for Inline Fixed Panel, 3/8 in Panel Glass, 72 in
- Glass
- 3/8″
- Gap
- 3/16–1/2″
- Length
- 72″
- Material
- Clear polycarbonate with soft fin
- Mount
- press-on
- Trim
- Cut to size
Mounts on the FIXED panel; the long fin overlaps the swinging door across the slot. Sized to the panel's glass, which can differ from the door's.
⚠ Never mount an h-jamb on the swinging door — it will rake the panel edge and tear its fin.
H-Jamb Shower Seal for Inline Fixed Panel, 1/2 in Panel Glass, 72 in
- Glass
- 1/2″
- Gap
- 3/16–1/2″
- Length
- 72″
- Material
- Clear polycarbonate with soft fin
- Mount
- press-on
- Trim
- Cut to size
Mounts on the FIXED panel; the long fin overlaps the swinging door across the slot. Sized to the panel's glass, which can differ from the door's.
⚠ Never mount an h-jamb on the swinging door — it will rake the panel edge and tear its fin.
Frequently asked questions
Does the h-jamb go on the door or the fixed panel?
The fixed panel, always. Mounted on the swinging door it would rake across the panel edge on every swing and tear its own fin off.
What gap can an h-jamb seal cover?
Standard fins bridge slots of roughly 3/16 to 1/2 inch. Measure the slot at top and bottom; a strongly tapered slot may seal better with a 180° magnetic pair instead.
Is an h-jamb the same as a 180-degree seal?
They overlap. "180° seal" describes any seal for an inline door-panel joint — h-jambs are the panel-mounted version, and 180° magnetic pairs are the latching alternative.