Why steam glass is different
An ordinary shower enclosure only needs to control splashing water, so a gap at the top is normal and even helpful for airflow. A steam shower has the opposite job: it must trap heat and vapor so the steam reaches and holds the temperature you want. That means the enclosure runs from floor to ceiling, with the glass and door sealed on essentially every edge. The glass has to contain a humid, pressurized environment rather than just block spray — a fundamentally different engineering target that shapes height, hardware, and sealing from the start.
Full-height enclosure and the transom
Steam enclosures reach the ceiling, and because the door rarely runs the full height on its own, the gap above it is closed with a fixed glass panel called a transom. The transom seals the top of the enclosure while keeping the open, all-glass look. Many designs include an operable transom vent — a small section that opens — so you can release steam and let the shower dry out after use. Ceiling height, any sloped or vaulted ceiling, and where the door swings all factor into how the transom and panels are laid out, which is why steam enclosures are measured and fabricated one-off.
Sealing, hardware, and keeping steam in
The performance of a steam shower lives in its seals. Door sweeps, jamb seals, and sealed glass-to-glass and glass-to-wall joints work together to keep vapor inside and away from the surrounding cabinetry, mirrors, and drywall. Hinges and hardware should be specified for a constant high-humidity environment. None of this should make the enclosure feel heavy or boxed in — done well, a steam enclosure still reads as clean frameless glass — but the difference between a steam shower that holds temperature and one that leaks heat is almost always in how carefully these joints are sealed and engineered.
Ventilation, coordination, and planning ahead
Because a steam shower is a sealed, high-humidity box, ventilation is part of the design, not an afterthought. The enclosure needs a way to dry out — typically an operable transom vent plus good bathroom exhaust — so moisture does not linger and feed mildew. The glass also has to be coordinated with the steam generator, the waterproofing, the sloped ceiling if there is one, and the controls. The cleanest results come from involving your glass fabricator early, while the layout is still on paper. Talk through your steam plans during the free measurement so the enclosure is engineered around your system rather than fitted around finished work.