Multiwall Polycarbonate Sheets for Roofing and Greenhouses
HSQY PLASTIC manufactures and supplies multiwall polycarbonate sheets for greenhouses, roofing, skylights, canopies, architectural glazing, covered walkways, swimming pool enclosures, industrial daylighting and other construction applications.
Also known as twinwall polycarbonate sheets, hollow polycarbonate sheets, cellular polycarbonate panels or multi-wall PC sheets, these panels contain internal ribs and air chambers that combine light transmission, impact resistance and thermal insulation while keeping the panel relatively lightweight.
HSQY currently supplies twinwall, triplewall, multiwall and selected honeycomb-style structures. Main standard thicknesses include approximately 4, 5, 6, 8, 10, 12 and 16 mm, with special structures and thicker project specifications available subject to confirmation.
What Is a Multiwall Polycarbonate Sheet?
A multiwall polycarbonate sheet is an extruded polycarbonate panel made with two or more outer walls connected by internal ribs.
The hollow air spaces between the walls reduce heat transfer compared with a single solid panel of similar area while also increasing panel rigidity without adding the same amount of material weight.
The number, orientation and geometry of internal ribs create different structures such as twinwall, triplewall, X-structure and honeycomb panels. Each structure provides a different balance of light transmission, insulation, stiffness, weight and load-bearing capability.
Multiwall Polycarbonate Sheet Structures
| Structure | Typical Thickness | Main Characteristics | Typical Applications |
| Twinwall / Double Wall | 4, 5, 6, 8, 10 mm | Lightweight, good light transmission and practical insulation | Greenhouses, canopies, patios, skylights and general roofing |
| Triplewall | 10, 12, 16 mm | Additional internal wall for improved rigidity and thermal insulation | Commercial greenhouses, skylights and higher-performance roofing |
| X-Structure / Reinforced Multiwall | Project-specific | Additional diagonal ribs can increase panel rigidity | Larger-span glazing, roofs and architectural applications |
| Honeycomb / Multi-Chamber | Project-specific | Dense internal cell structure for increased stiffness and insulation | Architectural roofs, facades, large skylights and insulated glazing |
Multiwall Polycarbonate Sheet Specifications
| Product | Multiwall Polycarbonate Sheet / Hollow Polycarbonate Sheet |
| Material | Polycarbonate (PC) |
| Twinwall Thickness | 4, 5, 6, 8 and 10 mm |
| Triplewall Thickness | 10, 12 and 16 mm |
| Special Structures | Multiwall, X-structure, reinforced and honeycomb designs subject to project specification |
| Standard Width | 2100 mm for mainstream products |
| Other Widths | Selected products and projects can be discussed in approximately 1220, 1560, 1820 and 2150 mm widths |
| Length | Standard and custom lengths available according to thickness, transportation and project requirements |
| Colors | Clear, opal, grey, bronze, blue, lake blue, green, emerald and custom colors |
| UV Protection | UV-protected outdoor grades available; one-side or project-specific two-side UV protection should be confirmed before ordering |
| Functional Options | Anti-condensation, solar-control, IR-control and other specialty options subject to product development and project confirmation |
| Main Applications | Greenhouses, roofing, skylights, canopies, covered walkways, facades, partitions and pool enclosures |
Why Choose Multiwall Polycarbonate?
Thermal Insulation: Internal air chambers reduce heat transfer compared with a single-layer sheet, making multiwall PC particularly suitable for greenhouses and insulated daylighting.
High Impact Resistance: Polycarbonate provides strong resistance to hail, accidental impact and handling damage compared with many brittle glazing materials.
Lightweight Construction: Hollow cellular construction reduces material weight and can simplify transport, lifting and installation.
Natural Daylighting: Clear and translucent panels allow daylight into greenhouses, roofs, skylights and buildings while reducing dependence on artificial lighting during daylight hours.
UV-Protected Options: Suitable outdoor grades use UV protection to reduce yellowing and surface degradation under prolonged sunlight exposure.
Multiple Structures: Twinwall, triplewall and reinforced cell structures allow the project designer to balance light transmission, rigidity and insulation.
Easy Fabrication: Panels can be cut and drilled using appropriate tools and can be cold curved within the permitted bending radius for suitable architectural applications.
Thermal Insulation and U-Value
One of the main advantages of multiwall polycarbonate is the insulating effect created by its enclosed air chambers.
In general, increasing panel thickness and adding additional walls or chambers can reduce heat transfer. However, the actual U-value or thermal transmittance depends on the exact wall structure, thickness, cell geometry and test method.
For architectural, greenhouse or energy-code projects, buyers should request the U-value for the exact HSQY panel specification rather than applying one generic thermal value to all multiwall sheets.
Light Transmission and Daylighting
Light transmission varies according to panel color, thickness, number of walls and cellular structure.
Clear twinwall panels generally provide the highest natural light transmission, while opal and tinted panels reduce direct brightness and increase light diffusion or solar shading.
| Color | Main Characteristic | Typical Application |
| Clear | Maximum natural daylight within the selected structure | Greenhouses, skylights and daylight roofing |
| Opal / Milky White | More diffuse light and reduced direct glare | Canopies, commercial roofs, walkways and architectural glazing |
| Bronze / Grey | Reduced visible brightness with tinted appearance | Patios, canopies, facades and shading applications |
| Blue / Green | Decorative tint with reduced direct light | Architectural roofs, pools, walkways and decorative glazing |
Multiwall Polycarbonate for Greenhouses
Greenhouse polycarbonate sheets need to balance daylight, thermal insulation, impact resistance, condensation control and durability.
Twinwall panels are commonly considered for general hobby and commercial greenhouse construction, while thicker triplewall or more complex cellular structures may be selected where improved insulation or rigidity is required.
The final specification should consider local climate, winter temperature, wind load, snow load, greenhouse span, crop light requirement and heating cost.
Twinwall Polycarbonate for Greenhouses
HSQY twinwall polycarbonate panels are currently available in common 4, 5, 6, 8 and 10 mm thicknesses.
Thinner twinwall sheets can be suitable for lightweight structures and moderate climates, while 8 mm and 10 mm products can provide increased rigidity and insulation where required.
Thickness selection should still be based on frame spacing and structural loading rather than greenhouse type alone.
Triplewall Polycarbonate for Higher Insulation
Triplewall polycarbonate adds another internal wall and air chamber compared with conventional twinwall construction.
HSQY currently lists 10, 12 and 16 mm triplewall options. These panels can be considered for larger commercial greenhouses, skylights and roofing projects where improved rigidity and thermal performance are priorities.
Multiwall Polycarbonate for Roofing and Skylights
Multiwall PC sheets are used for translucent roofing where daylight, insulation and lightweight construction are required.
Typical projects include industrial roof lights, commercial skylights, entrance canopies, patios, covered walkways, carports and swimming-pool covers.
Roofing design should consider panel span, slope, support spacing, wind uplift, snow load, drainage, connection profiles and thermal expansion.
For application-specific roof products, customers can also review our Polycarbonate Roofing Sheets.
Multiwall Polycarbonate for Canopies and Walkways
Multiwall panels can provide weather protection while maintaining daylight for entrances, patios, pedestrian walkways and parking structures.
Clear panels maximize daylight, while bronze, grey, opal and other tinted panels can be selected when glare or visual shading needs to be reduced.
Multiwall Polycarbonate for Architectural Glazing
Architects can use cellular polycarbonate for translucent facades, partitions, rooflights and daylight walls where privacy, diffusion and low panel weight are useful.
For structural architectural projects, the exact panel structure should be selected using design loads, span tables, thermal data and connection-system requirements.
Twinwall vs. Triplewall vs. Honeycomb Polycarbonate
| Feature | Twinwall | Triplewall | Honeycomb / Reinforced |
| Internal Structure | Two outer walls with connecting ribs | Three main walls with additional air chamber | Multiple internal cells or reinforced ribs |
| Weight | Lowest among comparable standard structures | Moderate | Depends on cell design |
| Insulation | Good | Better than comparable twinwall construction | Designed for higher insulation or rigidity depending on structure |
| Light Transmission | Generally higher for equivalent color | Slightly reduced due to additional walls | Depends strongly on internal cell geometry |
| Typical Application | General roofing and greenhouses | Commercial greenhouses and higher-performance glazing | Architectural roofs and more demanding structural projects |
How to Choose Multiwall Polycarbonate Thickness
Sheet thickness should not be selected by application name alone. Panel span, support spacing, wind load, snow load, expected impact, insulation target and wall structure all influence the correct specification.
| Thickness | General Selection Direction |
| 4–5 mm Twinwall | Lightweight covers, small greenhouses and projects with close structural support |
| 6 mm Twinwall | Common greenhouse, canopy and light roofing applications |
| 8–10 mm Twinwall | Larger greenhouses, skylights and projects requiring more rigidity and insulation |
| 10–12 mm Triplewall | Commercial greenhouses and higher-performance roof glazing |
| 16 mm Triplewall | Applications prioritizing insulation and greater structural stiffness |
| 20–25 mm or Specialized Multiwall | Project-specific architectural or high-insulation applications; confirm structure and availability before specification |
UV Protection for Outdoor Polycarbonate
Polycarbonate used outdoors should be selected with suitable UV protection.
UV-protected multiwall sheets generally use a co-extruded protective surface designed to reduce long-term yellowing and degradation caused by sunlight.
When a panel has UV protection on one side, the UV-protected face must be installed toward the exterior sunlight. Protective film or printing on the panel normally identifies the correct installation side.
For structures exposed to sunlight from both sides, request a suitable double-sided UV specification rather than assuming every sheet includes two-side protection.
Anti-Condensation Polycarbonate for Greenhouses
Greenhouses and humid enclosures can experience condensation on the inner surface of polycarbonate roofing.
Suitable anti-condensation or anti-drip surface treatments can help water spread into a thinner film rather than forming large droplets under appropriate conditions.
Anti-condensation performance is product-specific and should be discussed during specification if greenhouse crop protection, pool enclosures or humid interior environments are involved.
Solar-Control and Heat-Reducing Multiwall Panels
High daylight transmission is not always the only design objective. In hot climates, reducing solar heat gain can also be important.
Tinted, reflective, opal or application-specific IR-control structures can be evaluated when a project needs to balance daylight with heat control.
For architectural projects with defined solar heat gain coefficient or shading-coefficient requirements, request project-specific optical data for the exact color and structure.
Multiwall vs. Solid Polycarbonate Sheet
| Feature | Multiwall Polycarbonate | Solid Polycarbonate |
| Structure | Hollow cellular structure | Continuous solid panel |
| Thermal Insulation | Air chambers provide improved insulating performance | Lower insulation at comparable panel thickness |
| Direct Visibility | Internal ribs remain visible | Better direct clear visibility |
| Weight | Lower due to hollow design | Higher for the same nominal thickness |
| Typical Applications | Greenhouses, roofs, skylights and insulated daylighting | Machine guards, safety glazing and transparent barriers |
For applications requiring direct clear visibility and high impact protection, review our Solid Polycarbonate Sheets.
How to Install Multiwall Polycarbonate Sheets
Install the UV-Protected Side Facing Out
If the sheet has one-sided UV protection, the marked UV-protected face must face the sun and exterior weather.
Install the Ribs in the Drainage Direction
Internal channels should normally run in the direction of roof slope or vertical drainage so condensation can move toward the lower end rather than remain trapped inside the cells.
Allow for Thermal Expansion
Polycarbonate expands and contracts as temperature changes. Connection profiles, drilled holes and panel-edge clearances must allow sufficient movement.
Use Suitable Joining Profiles
Compatible polycarbonate or aluminum H-profiles, U-profiles, glazing bars, screws and washers should be selected according to panel thickness and structural design.
Seal the Open Channels Correctly
Open panel ends should be protected against dust, insects and moisture using appropriate tape and end profiles.
Depending on installation direction and system design, the upper end may require a closed protective tape while the lower end can use a ventilated or anti-dust tape that allows moisture drainage.
Maintain Adequate Roof Slope
Roofing should have sufficient slope for rainwater drainage. Required slope depends on panel system, roof geometry and local construction requirements.
Cutting Multiwall Polycarbonate Sheet
Multiwall sheets can be cut using suitable fine-tooth circular saws, table saws or other plastic-sheet cutting equipment.
Support the panel close to the cutting line to reduce vibration. After cutting, remove chips and dust from internal channels before sealing the sheet ends.
Keep protective film on the panel during cutting and installation where practical to reduce surface scratching.
Can Multiwall Polycarbonate Be Cold Bent?
Suitable multiwall polycarbonate sheets can be cold curved for arches, canopies and other curved glazing designs.
The minimum bending radius depends on panel thickness and internal structure. Bending a sheet tighter than its approved radius can create excessive stress and reduce service life.
Provide the required arch radius together with panel thickness when requesting material for curved structures.
Fire Performance of Multiwall Polycarbonate
Fire performance varies according to polycarbonate resin, wall structure, thickness and test standard.
Do not apply one generic UL, EN or building-material classification to every HSQY multiwall panel.
If your project requires UL 94, EN 13501, building-code fire classification or another standard, provide the exact specification so HSQY can confirm the appropriate material and available documentation.
Cleaning and Maintenance
Clean polycarbonate panels with clean lukewarm water, mild soap or a compatible neutral detergent and a soft cloth or sponge.
Avoid abrasive brushes and aggressive solvents that have not been confirmed as compatible with polycarbonate.
Greenhouse owners should also inspect sheet ends, sealing tapes, profiles and internal channels periodically for damage or contamination.
How to Choose the Right Multiwall Polycarbonate Sheet
1. Define the Application
Specify greenhouse, skylight, canopy, roof, facade, partition, pool enclosure or another use.
2. Select the Wall Structure
Choose twinwall for lightweight general applications or consider triplewall and reinforced structures where additional insulation or rigidity is required.
3. Select the Thickness
Panel thickness should be matched to span, wind load, snow load, insulation and frame spacing.
4. Define the Light Requirement
Choose clear panels for maximum daylight, opal for diffusion, or tinted colors when glare and solar heat need to be reduced.
5. Confirm Thermal Insulation
If the project has a U-value or energy-code target, provide the required value so the exact panel structure can be evaluated.
6. Confirm UV Exposure
Outdoor applications should specify one-side or two-side UV exposure requirements.
7. Confirm Anti-Condensation Requirements
Greenhouses and humid structures may benefit from an application-specific anti-condensation surface.
8. Provide Structural Loading
Wind load, snow load, panel span and support spacing are essential for roof and facade projects.
9. Confirm Installation Accessories
Confirm connection profiles, end profiles, screws, washers, sealing tape and ventilation tape together with the panel specification.
10. Test Samples and Review Drawings
For large projects, confirm panel samples, color, structure and installation drawings before bulk production.
Custom Multiwall Polycarbonate Sheets
HSQY supports customized multiwall polycarbonate projects for greenhouse builders, roofing contractors, building-material distributors, architects and industrial customers.
Custom options can include:
Custom thickness
Twinwall, triplewall or specialized multiwall structures
Custom sheet length
Project-specific widths
Clear, opal, bronze, grey, blue and green colors
Custom colors
UV-protected grades
Two-side UV protection where required
Anti-condensation surfaces
Solar-control or IR-control options
Cut-to-length panels
Custom export packaging
Private-label packaging for distributors
Multiwall Polycarbonate Quality Control
Relevant inspection and project-approval parameters can include:
Panel thickness and tolerance
Sheet width and length
Wall structure and rib geometry
Panel weight per square meter where specified
Color consistency
Light transmission where specified
U-value where specified
UV-protection side
Surface quality
Impact performance
Cold-bending compatibility
Anti-condensation performance where specified
Fire classification where specified
Profile and accessory compatibility
Export packing quality
Packing and International Shipping
Multiwall polycarbonate panels are lightweight but relatively large, so sheet length, pallet dimensions and container-loading efficiency can significantly affect international freight cost.
Protective film and suitable export wrapping help protect the sheet surfaces during handling and transportation.
Buyers should confirm sheet length, quantity, pallet requirements, container type and whether accessories will be loaded together before shipment.
Why Choose HSQY as Your Multiwall Polycarbonate Manufacturer?
Multiple Structures: HSQY supplies twinwall, triplewall, multiwall and selected honeycomb-style polycarbonate structures.
Wide Thickness Selection: Main current products include 4–10 mm twinwall and 10–16 mm triplewall panels, with special structures available for project evaluation.
Greenhouse and Roofing Solutions: Material can be selected according to daylight, insulation, UV exposure and structural requirements.
Multiple Colors: Clear, opal, grey, bronze, blue, green and other colors can be discussed for different daylighting and architectural requirements.
Custom Lengths: Panel length can be optimized according to greenhouse or roofing dimensions and transportation requirements.
Broader PC Sheet Portfolio: HSQY also supplies Solid Polycarbonate Sheets, Corrugated Polycarbonate Sheets and Polycarbonate Roofing Sheets for different construction systems.
Sample Evaluation: Samples can be discussed for checking thickness, wall structure, color, clarity and project compatibility before bulk ordering.
Information Needed for a Multiwall Polycarbonate Quote
| Application | Greenhouse, roofing, skylight, canopy, facade, partition or other use |
| Wall Structure | Twinwall, triplewall, X-structure, honeycomb or recommendation required |
| Thickness | 4, 5, 6, 8, 10, 12, 16 mm or project-specific specification |
| Sheet Size | Required width × length |
| Color | Clear, opal, grey, bronze, blue, green or custom color |
| Light Requirement | Required light transmission, diffusion or shading target where applicable |
| Thermal Requirement | Required U-value or insulation target where applicable |
| UV Requirement | One-side or two-side outdoor UV exposure |
| Structural Load | Wind load, snow load, panel span and support spacing where relevant |
| Special Functions | Anti-condensation, solar control, fire performance or other requirements |
| Quantity | Required square meters or number of sheets |
| Destination | Destination country and port |
Multiwall Polycarbonate Sheet FAQ
What is multiwall polycarbonate sheet?
Multiwall polycarbonate is a hollow cellular PC sheet containing multiple surfaces and internal ribs. The air chambers improve thermal insulation and stiffness while keeping the panel lightweight.
Is twinwall the same as multiwall polycarbonate?
Twinwall is one type of multiwall polycarbonate. Multiwall is the broader category and can also include triplewall, four-wall, X-structure and honeycomb-style panels.
What is the difference between twinwall and triplewall polycarbonate?
Twinwall has two main external walls connected by ribs. Triplewall adds another wall and air chamber, which generally increases rigidity and insulation but can slightly reduce light transmission.
What thicknesses does HSQY offer?
Current HSQY twinwall products include 4, 5, 6, 8 and 10 mm, while current triplewall products include approximately 10, 12 and 16 mm. Special multiwall structures can be discussed separately.
What width is multiwall polycarbonate sheet?
HSQY's mainstream twinwall and triplewall specifications use approximately 2100 mm standard width. Other widths can be discussed according to the product and project.
What thickness polycarbonate is best for a greenhouse?
There is no universal greenhouse thickness. Small structures in moderate climates may use thinner twinwall panels, while colder climates, wider spans or higher wind and snow loads may require thicker twinwall or triplewall panels.
Is 6 mm polycarbonate good for a greenhouse?
A 6 mm twinwall sheet is commonly considered for greenhouse applications, but suitability depends on frame spacing, local climate, wind, snow and required insulation.
Is 8 mm or 10 mm polycarbonate better for a greenhouse?
A thicker panel can provide additional stiffness and insulation, while a thinner panel may provide lower weight and cost. The better choice depends on climate and structural design.
Does multiwall polycarbonate provide insulation?
Yes. Air trapped inside the cellular structure reduces heat transfer compared with a single solid sheet. The exact U-value depends on panel thickness and internal structure.
Which polycarbonate structure has the best insulation?
In general, thicker panels with more chambers can provide better insulation, but exact performance depends on cell geometry. Compare U-values for the exact products rather than only counting the number of walls.
Does multiwall polycarbonate block UV?
Outdoor multiwall sheets can be supplied with a UV-protected surface. The UV-protected face should be installed toward sunlight according to the product markings.
Which side of polycarbonate faces the sun?
For one-side UV-protected material, the marked UV-protected side must face outward toward the sun. Check the protective-film markings before removing the film.
Should polycarbonate channels run vertically?
For vertical glazing, channels should normally run vertically. For sloped roofing, channels should run down the roof slope so condensation can drain toward the lower end.
Do I need to seal the ends of twinwall polycarbonate?
Yes. Open cells should be protected to reduce dust, insects and moisture entering the channels. Appropriate sealing and ventilation tapes should be selected according to installation orientation.
Can multiwall polycarbonate be cut?
Yes. Panels can be cut using suitable fine-tooth saws and plastic-sheet fabrication equipment. Clean the internal channels after cutting and before sealing the ends.
Can twinwall polycarbonate be bent?
Suitable sheets can be cold curved within their approved minimum bending radius. Required radius depends on panel thickness and internal structure.
Is polycarbonate better than glass for a greenhouse?
Multiwall polycarbonate is lighter and provides cellular insulation and high impact resistance. Glass can offer different optical and surface properties. The better material depends on structural, thermal, visual and budget requirements.
Does HSQY offer anti-condensation greenhouse panels?
Anti-condensation requirements can be discussed for suitable projects. Specify greenhouse conditions and required surface performance when requesting a quotation.
Does HSQY offer custom colors?
Yes. HSQY offers clear, opal, grey, bronze, blue, green and other colors, with custom colors subject to production feasibility and order quantity.
Can HSQY customize sheet lengths?
Yes. Custom sheet lengths can be discussed according to extrusion, transportation and project requirements.
Is multiwall polycarbonate fire resistant?
Fire behavior depends on resin, thickness, wall structure and the applicable test method. If a project requires a specific fire classification, request documentation for the exact panel specification.
Can I request multiwall polycarbonate samples?
Available samples can be discussed for checking thickness, wall structure, color, light transmission and surface appearance before bulk ordering.
What information do I need for a quotation?
Provide application, wall structure, thickness, width, length, color, quantity, UV requirement, wind and snow loads where relevant, installation drawings and destination.
Request a Multiwall Polycarbonate Sheet Quote
Looking for a reliable multiwall polycarbonate sheet manufacturer, twinwall greenhouse panel supplier or customized insulated polycarbonate roofing solution?
Send HSQY your required thickness, panel dimensions, application, color and estimated quantity. For greenhouse and roofing projects, include frame spacing, wind load, snow load, UV exposure and insulation requirements where available so our team can recommend a suitable twinwall, triplewall or multiwall structure.
