Why would a project choose polycarbonate for a noise wall when acrylic is clearer, lighter and cheaper per square metre? The answer is usually one line in the geotechnical report: rockfall, or a vandalism history.
Where PC earns its place
Solid polycarbonate at 8 mm or 10 mm takes a far harder hit than acrylic of the same thickness without shattering into edges. On cut-slope roads, tunnel portals and urban walls with a history of thrown objects, that impact margin is worth the trade. Acrylic wins on light transmission — around 92% against roughly 88% for clear PC — and on weight, which matters when panels are lifted by hand.
A cut-slope wall in practice
A mountain road in a wet climate specified 10 mm clear polycarbonate for a 1,200 m wall because the slope above it shed fist-sized stone every spring. Panels ran 2,000 mm × 3,000 mm between posts at 2,500 mm centres, with 20 mm holes to absorb thermal movement — PC moves about as much as acrylic, roughly 0.06 mm per metre per degree.
Every panel carried a hard coat on both faces. That is not optional here: bare polycarbonate scratches to a haze within two seasons of cleaning grit off a road-side panel. With the coating, transmission stayed above 85% after three years.
Three specification traps
- Coating on both faces. Single-side coated panels get installed backwards about a third of the time.
- Not acrylic’s drilling spec. PC needs the same generous clearance but also a de-burred hole; a ragged edge starts a crack under load.
- UV grade, not general purpose. Exposed PC needs a UV-stabilised grade or the surface yellows and embrittles.
The acrylic-versus-PC choice for transparent walls is compared in transparent acoustic barriers, and impact-driven selection for exposed structures in clear highway noise barrier panels.
Frequently Asked Questions
Q: When should a noise wall use polycarbonate instead of acrylic?
A:Where impact is the governing risk — rockfall slopes, tunnel portals, or walls with a vandalism history. Polycarbonate absorbs a harder hit without shattering, at the cost of a few percent light transmission and higher weight.
Q: Does polycarbonate noise barrier need a hard coating?
A:On any exposed site, yes, and on both faces. Bare PC hazes from grit and cleaning within a couple of seasons; a hard coat keeps transmission above 85% after several years of road-side service.
Send your sound-wall drawings, span between posts and required Rw to oversales@rpplexiglass.com for a cast acrylic panel quotation with drilling and edge details.