The question from the architect was simple: can we get a 12 mm translucent panel in this exact amber, 1.5 by 3 m, fixed to a steel sub-frame on a west elevation with a 50 C surface swing. The answer was yes, but only if the fixing detail allowed the panel to move, and that is where most acrylic facade cladding projects go wrong.
Acrylic on a facade is not glass. It expands roughly five times as much, it softens far earlier, and it is more sensitive to concentrated loads at fixings. What it gives back is weight, formability and colour depth that glass cannot match at the same budget.
Acrylic facade cladding panel sizes and joints
- 6 mm: small infill panels inside a frame, up to 900 x 1500 mm
- 8 mm to 10 mm: rainscreen modules up to 1.5 x 3 m
- 12 mm to 15 mm: large format or self-supporting modules with stiffeners
- Joint: 8 mm to 12 mm open joint on a ventilated cavity, or aluminium expressed joint
On the Dubai entrance canopy that started this conversation, panels were 10 mm UV-stabilised cast acrylic at 1.2 x 2.4 m, held on a stainless sub-frame with 4 mm clearance holes and EPDM washers. The gap between panels was 10 mm, dark-backed so the joint read as a line rather than a shadow. Two summers in, no panel had bowed and no screw line had crazed.
The detail that fails is the fully restrained panel: clamped at four edges with no clearance, on a facade that reaches 60 C in sun. The sheet cannot expand, so it relieves stress by cupping. Once a panel cups, water sits on the joint and the sealant starts to work loose.
UV, cleaning and the colour that must not drift
Colour is where a facade specification gets tested. Tinted acrylic should come from one casting batch, and the buyer should hold a retained sample. Two batches of the same nominal amber can differ enough to read as a patchwork on a large elevation. If a phased project will need panels in year two, reserve colour from the first cast.
Cleaning is a maintenance instruction, not a footnote. Alkaline builders clean and abrasive pads will dull a facade within a season. Warm water, a neutral detergent and a soft cloth, scheduled twice a year, keeps the surface readable. The safe and unsafe agents are listed in our cleaning and maintenance guide.
One more interface worth pinning down early: the panel module against standard acrylic sheet sizes. Designing to 1220 x 2440 mm modules with a 10 mm joint keeps offcut waste under 8 percent; designing to 1100 x 2300 mm pushes it past 20 percent.
Share your elevation drawing, panel module and fixing system with oversales@rpplexiglass.com for a cladding panel quotation.
Frequently Asked Questions
Can acrylic be used as exterior facade cladding?
Yes, in a rainscreen system with a ventilated cavity and a sub-frame. UV-stabilised cast acrylic holds colour and gloss for many years, but it must be free to expand and must never be mechanically clamped on all four edges.
How much expansion gap does a cladding panel need?
Allow about 0.065 mm per metre per degree C. A 1.5 m panel across a 50 C surface swing needs roughly 5 mm of movement, split between the two edges, plus a safety margin.
Does acrylic cladding yellow outdoors?
Standard cast acrylic can yellow after long UV exposure; UV-stabilised grades resist far longer. Specify the stabilised grade in writing, with a colour target and a sample panel retained for comparison at handover.