A polycarbonate atrium glazing scheme is decided by access as much as by light. Panels twelve metres up that nobody can reach will not be cleaned, and the material selection has to assume that from the start.
A shopping centre in Birmingham glazed a 40 m clerestory band with 12 mm polycarbonate. The panels performed well for three years; the interior face, never cleaned, hazed enough that the daylight factor dropped visibly by year four.
Polycarbonate atrium glazing thickness and spans
- Clerestory to 1.2 m panels: 10 mm solid
- Larger bays: 12 to 16 mm
- Multiwall: where insulation outweighs clarity
- Movement: 3 to 5 mm joint per panel over a long band
Long horizontal bands are the hardest case. A 40 m run at 25 C swing moves about 250 mm in total, and panels fixed hard at both ends buckle. One fixed edge per panel plus an open joint is the detail that keeps the band flat.
Access, cleaning and the fire question
Cleaning is a design decision. An internal gantry, a MEWP route from the concourse, or a cradle system has to be planned with the structure. Where none exists, a coated panel that releases dirt is the only sensible specification, and even then it will need a wash every few years.
The fire strategy settles the material. An atrium is frequently a protected space and a smoke reservoir; polycarbonate is combustible, so where a class is named, the answer is glass or a tested system. That argument is held before the order, not after.
Thermal comfort at high level is the reason many atria feel hot. High glazing over an occupied concourse plus a polycarbonate roof creates a stack; opening vents at the ridge and shading the south band reduce the load far more than a coating will.
Where the atrium glazing meets a roof light, the detailing overlaps with polycarbonate parking structure glazing, and the maintenance regime for a coated panel is in the cleaning and maintenance guide.
Send your elevation, access method and fire strategy to oversales@rpplexiglass.com for a glazing proposal.
Frequently Asked Questions
What polycarbonate for high atrium glazing?
10 mm solid up to 1.2 m spans, 12 to 16 mm above that. Multiwall is an option where insulation matters more than clarity, but the visual result is different and should be approved on a sample.
How is high glazing cleaned?
From a cradle, a MEWP or an internal gantry, planned at design stage. If no access is provided, the panels will not be cleaned, and the material choice should reflect that with a coated, dirt-releasing surface.
Is polycarbonate acceptable in a fire strategy?
Only as part of an assessed assembly. Polycarbonate is combustible, and an atrium is often a protected escape route. Where a class is required, glass or a rated system applies, and the decision belongs to the fire engineer.