Twin-wall polycarbonate is a multiwall sheet with two outer skins connected by internal ribs. It creates enclosed cells that change stiffness, heat transfer, light and condensation behaviour. Wall count alone does not select a panel; compare the actual structure, thickness, mass, span data and project conditions.
Read the section, not just the name
“Twin-wall,” “double-wall” and “multiwall” describe families, not a single construction. Two sheets with the same nominal thickness may have different rib spacing, geometry, weight, resin grade, colour or UV protection. Request a section drawing and the offered product’s current data before comparing quotations.
Connect structure to the support layout
Internal ribs contribute to directional stiffness. Span tables are tied to panel direction, supports, load case and deflection criterion. Cutting the sheet across cells, changing the length or reducing edge engagement can alter the assembly. The project engineer must use the actual construction and applicable wind, snow or maintenance loads.
Review light and thermal goals separately
More cells do not automatically give the best daylight result. Colour, surface, wall geometry and thickness affect transmission, diffusion and appearance. Thermal performance also belongs to a named panel and test basis. Ask for comparable methods, then inspect a sample under the project lighting.
Protect and drain the channels
- run ribs in the direction required by the system, commonly toward drainage;
- remove swarf without driving debris deeper into cells;
- use the specified upper and lower closure treatments;
- keep drainage and ventilation paths open where the system requires them;
- use compatible profiles, sealants and cleaners.
Specify the complete order
State panel section, thickness, width, length, colour, UV face, cut orientation, quantity and packing. Add the support drawing, design loads, flashing concept and documentation requirement. A retained sample helps control appearance but does not replace dimensional or structural acceptance criteria.
SinoPlastix can identify an offered multiwall construction and review cutting or packing needs. The written quotation should be checked against the section and span basis; a generic twin-wall label is insufficient approval evidence.