Palram twin wall polycarbonate
Polycarbonate greenhouse


Rigid-Structured Multiwall Polycarbonate Roofing Sheets for Light Transmission and Thermal Insulation

SUNLITE is a family of flat, twin wall polycarbonate panels and multiwall polycarbonate sheet products that feature a cellular structure.
The insulating air spaces help reduce thermal transfer and result in a rigid, impact-resistant, thermally insulating sheet that is significantly lighter in weight than solid polycarbonate, acrylic, or glass. SUNLITE polycarbonate sheets offer energy efficiency that is better than any single-layer sheet. The SUNLITE multiwall polycarbonate family offers a variety of options - from built-in condensation control for greenhouses & garden centres to advanced SolarSmart™ tints that reduce solar heat gain. Find the SUNLITE polycarbonate sheets that best suit your needs.

Royal Institute of British Architects

Royal Institute of British Architects


Architects usually have a clear aesthetic and functional vision for a structure, but may need support and collaboration in specifying and selecting the glazing product that perfectly fits this vision.
Palram offers four different types of polycarbonate glazing products, including flat solid sheets, multiwall sheets, single-layer corrugated sheets, and complete panel systems. Our Project Support team of engineers can help you evaluate these options with the goal of meeting your design aspirations, and optimizing budget and performance objectives.



SolarSmart™ technology defies the standard relation between light transmission and shading coefficient. With selective colour and solar transmission, SolarSmart SUNLITE multiwall polycarbonate sheets admit more natural daylight while blocking and reflecting infrared wavelengths. Reducing heat build-up, SUNLITE SolarSmart sheets support versatile, flexible specifications for natural light in architectural design.



Palram's SUNLITE multiwall polycarbonate sheet product range is available in a wide range of colours, thicknesses, and structures.  This range gives you the ability to match the specifications of your application, with the right balance of light transmission, thermal properties, weight, load-bearing, impact resistance, and aesthetics.

SUNLITE twin wall polycarbonate sheet offer flexibility and lightweight, with UV protection. It is suitable both for indoor and outdoor applications.

SUNLITE triple wall polycarbonate sheets offer improved thermal insulation, with a more robust structure that performs better under heavier loads.


SUNLITE X-lite / SUNLITE V-structure multiwall polycarbonate sheets, with an internal diagonal structure, offer an excellent balance between weight and structural strength, and improved thermal insulation properties. This is the strongest and thickest version available. These robust multiwall sheets can carry loads better than any other multiwall polycarbonate alternative.

SUNLITE 7-wall multiwall polycarbonate sheets stretch further the thermal insulation properties of SUNLITE while retaining its low weight and high impact strength.

SUNLITE Plus multiwall polycarbonate greenhouse panels are manufactured with built-in condensation control. They are an excellent choice for greenhouse walls and glazing, reducing condensation accumulation and dripping.


StructureThickness (mm)Area Weight (Kg/m²)U-Value (W/m²•°K)Width 700 (mm)Width 980 (mmWidth 1050 (mm)Width 1200 (mm)Width 1220 (mm)*Width 1250 (mm)Width 1600 (mm)Width 1800 (mm)Width 1830 (mm)Width 2085 (mm)Width 2090 (mm)Width 2095 (mm)Width 2100 (mm)**
Twin Wall40.83.8
Twin Wall4.513.7
Twin Wall61.33.5
Twin Wall81.53.3
Twin Wall101.72.9
Triple Wall81.73
Triple Wall1022.7
Triple Wall162.72.3
7 Walls10**1.91.35
7 Walls162.651.75
7 Walls202.91.55
7 Walls253.41.39

Dimensions Note Other Structures, Dimensions And Weights Are Available Upon Request. Please Contact Your Palram Distributor For More Details.Rnrn* Available In USA Onlyrn** Width Of 7 Wall 10mm Is 2096mm Instead Of 2100mm.


Product Range

Sunlite®Standard sheet with UV protection on one side
Sunlite® UV2UV protection on both sides
ThermaGlas®With anti-condensation, for greenhouses
Sunlite® Solar ControlSolar metallic reflective heat blocking sheet
Sunlite® SLTHeat blocking and anti-condensation for garden centers
Sunlite® SmartSee-through sheet with advanced heat-blocking

Standard Color chart

StructureClearBronzeWhite OpalWhite DiffuserGreen**Blue**
Twin wall 4mm82%35%30%35%30%
Twin wall 4.5mm82%35%30%35%30%
Twin wall 6mm80%35%20%60%35%30%
Twin wall 8mm80%35%35%55%35%30%
Twin wall 10mm79%35%30%35%30%
Triple wall 8mm76%35%48%35%30%
Triple wall 10mm76%35%48%35%30%
Triple wall 16mm76%35%48%35%30%
X-Lite 16mm60%25%38%35%
V-Structure 20mm63%25%20%10%
V-Structure 25mm62%30%
V-Structure 32mm61%20%20%
V-Structure 35mm60%
V-Structure 40mm58%
X-Lite 20mm60%25%15%
X-Lite 25mm60%25%15%
X-Lite 32mm58%20%15%
X-Lite 35mm57%20%15%
X-Lite 40mm57%20%15%
7 Walls 10mm64%29%45%
7 Walls 16mm64%29%38%
7 Walls 20mm62%29%38%
7 Walls 25mm60%22%38%

Multi-Layered Colors


Standard Color TextLight Transmission Values Adhere To ASTM D-1003.
StructureBronze/OpalSolar Guard
X-Lite 20mm10%5%
X-Lite 25mm10%5%
X-Lite 32mm10%5%
X-Lite 35mm10%5%

Solar Smart Colors


Solar Color TextLight Transmission Values Adhere To ASTM D-1003.
StructureSolar IceSolar Control**CLSLTSmart Green
Twin wall 4mm30%
Twin wall 4.5mm30%
Twin wall 6mm30%
Twin wall 8mm25%45%/34%60%/55%
Twin wall 10mm25%60%/55%
Triple wall 8mm25%
Triple wall 10mm25%
Triple wall 16mm
X-Lite 16mm30%/25%
V-Structure 20mm18%
V-Structure 25mm
V-Structure 32mm
V-Structure 35mm
V-Structure 40mm
X-Lite 20mm0.220%20%/16%42%/35%
X-Lite 25mm0.220%20%/16%42%/35%
X-Lite 32mm0.220%20%/16%42%/35%
X-Lite 35mm0.220%20%/16%42%/35%
X-Lite 40mm20%


Solar Smart Colors Note** Solar Control Is Made To Order Only.Rn(Light Transmission / Solar Transmission - Where Available)
Multi Layered Colors NoteLight Transmission Values Adhere To ASTM D-1003.

Typical Physical Properties

Heat deflection temperature (HDT)D-648Load: 1.82 MP°C
Service Temperature - Short term°C-50 to +120
Service Temperature - Long term°C-50 to +100
Coefficient of linear thermal expansionD-696mm/mm °C6.5x10-⁵
Tensile strength at yieldD-63810 mm/minMPa62
Elongation at breakD-63810 mm/min%>90
Impact falling dartISO 6603/1J40-400
Practical thermal expansion/contractionmm/m Column 5, Row 10

Typical Physical Properties Notes     Physical Properties Data Adheres To ASTM Except Where Noted Otherwise

Flammability Properties


Physical properties data adheres to ASTM except where noted otherwise

BS 476/7Class 1
EN 13501B, s1, d0
ASTM E-84Class A

Flammability Notes      * Depends On Sheet Structure. For More Information Please Contact Your Palram Distributor.


Regulatory Code Compliance Certification

ICC (International Code Council)IBC-2012 (Light Transmitting Plastic)ESR-1893
NRC-CNRCCanadian NBC 2015 (Canopy Covering)CCMC Evaluation Report 13450-R

Frequently Asked Questions

How do I curve the polycarbonate to follow the façade curve?
+ -

All Palram polycarbonate products can be cold bent onsite during installation, subject to a minimum radius. The radius varies based on the chosen product. For flat sheets such as PALSUN & SUNLITE, the rule-of-thumb for the minimum radius is the thickness multiplied by 200. Please check the Palram catalog for more detailed specifications.

How do I specify the required thickness of the polycarbonate glazing material?
+ -

The recommended thickness of the polycarbonate glazing material is based on factors such as wind & snow load, panel size, and boundary conditions. Visit the Palram website for access to calculators that can help you determine the recommended thickness.

How do I reduce the heat build-up coming from the façade into the building?
+ -

In order to reduce heat build-up through the façade, Palram strongly recommends the use of its tinted SolarSmart™ panels. SolarSmart™ tints can be implemented in all Palram polycarbonate products. For more information, reference the Palram SolarSmart™ technology page.

How do I create a double skin glazing solution for façades and curtain walls?
+ -

Flat solid or multiwall sheets can be glazed in double skin applications using standard aluminum curtain wall profiles and EPDM gaskets. The SUNPAL system can be installed in a double skin application with a special aluminum profile provided by Palram.

Should products be pre-dried before thermoforming?
+ -

This depends on the production date and storage conditions of the product before thermoforming. It is recommended to check the product before thermoforming is attempted.

Is the PE film suitable for thermoforming applications?
+ -

Most of Palram's products that are delivered with PE film covering are suitable for thermoforming. In general, we recommend using clear PE and not printed PE.

What is the minimum allowed bending radius of polycarbonate?
+ -

The minimum allowed bending radius of the polycarbonate is 200 times the thickness of the sheet, for example, a 2 mm sheet has a minimum 400 mm bending radius.

Can I use multiwall polycarbonate sheets as a skylight combined with a metal roof?
+ -

Yes, you can by using domes or glazing solutions. Please contact Palram technical support for further information.

How do I install flat solid or multiwall polycarbonate sheets as skylights?
+ -

Flat solid or multiwall polycarbonate sheets need to be installed with designated aluminum profiles when used as a skylight.

Can the percentage of light transmission be controlled? I need a lot of light but I need it to be diffused.
+ -

Palram offers various LT% parameters - from 0% to 90%. In addition, we offer a color called a “diffuser” that allows 85% of the light in while diffusing it by 100%. The result is a light-transmitting panel that is not transparent but is highly translucent.

If polycarbonate sheets block UV radiation, why is there a "UV-side" that faces outwards?
+ -

Polycarbonate sheets block UV radiation by absorbing it. This absorption mechanism can cause degradation to the material, and to prevent this from happening, the sheet is coated with a special material.

For this reason, it is recommended that the sheets are installed with the marked UV protective layer facing outward. Moreover, most of the sheets are only protected on the side that is clearly marked as such.

How do I design the secondary steel support spacings for roofing/siding?
+ -

Palram created specific loading tables for each product. Please visit our website and download the specific catalog.

Can I install multiwall polycarbonate sheets horizontally for siding?
+ -

No. The multiwall channels should always be vertical to allow condensation water to drain out by gravity.

How do I clean the polycarbonate?
+ -

  • Never use abrasive or high alkaline cleaners on any Palram polycarbonate products.
  • Do not leave cleaners on Palram polycarbonate for extended periods of time. Rinse immediately with cold, clean water.
  • Do not apply cleaners in direct sunlight.
  • Never use sharp objects, squeegees or razors on polycarbonate.
  • Do not clean with gasoline.
  • Always practice safety first and never step directly on a polycarbonate panel.
  • Always test cleaners in a small inconspicuous area prior to cleaning the entire panel to ensure against adverse results.
  • Avoid allowing the pressure washer spray tip to come too close to the panel. Pressure washers often have enough pressure at the spray tip to penetrate or tear the panel.
  • Avoid dry cleaning as sand and dust particles clinging to the exterior of the panels may scratch the surface.

What is the meaning of Shading Coefficient (SC)?
+ -

Shading coefficient (SC) is a parameter that compares transparent and translucent materials with clear 3 mm glass with 87% LT ׂ(light transmission). The lower the value, the more convenient it is to stay under the material on warm, sunny days. In architectural projects, the SC should usually be between 0.3 to 0.5.

When should I use multiwall polycarbonate and when solid polycarbonate?
+ -

Multiwall polycarbonate should be used when the key design parameter is thermal insulation. Solid polycarbonate should be used when the key design parameter is acoustic insulation and glass-like appearance.

What is the difference between multiwall and solid polycarbonate?
+ -

Multiwall is a multi-cell structured sheet. Due to its multi-cell structure, it has superior thermal insulation and low area weight.

When should I specify a matte surface finish for the polycarbonate?
+ -

A matte surface finish is good if you want to avoid glare within your surroundings.

How do I determine the color, Light Transmission (LT) and haze properties of polycarbonate?
+ -

This decision depends on the application – some of the colors are transparent and some are translucent. If a see-through material is needed, then haze should be smaller than 1% and the LT% should be based on the illumination design. If a translucent effect is needed, then the haze should be 100% and the LT% based on the chosen color.

Where should I use profiled versus multiwall polycarbonate covering?
+ -

SUNTUF Plus profiled polycarbonate sheets provide the best light transmittance and UV light resistance, with exceptional load-bearing and impact-resistance properties. SUNLITE Plus multiwall PC sheets provide the best thermal insulation. In locations where you would prefer thermal insulation to light transmission, you should use SUNLITE Plus multiwall PC sheets.

Can I cover my old polyethylene greenhouse with polycarbonate while still keeping the old structure?
+ -

Yes, but with minor reinforcements to the structure in order to support the load.

Will polycarbonate light transmittance deteriorate over time?
+ -

PALRAM's polycarbonate products are shielded with a UV protection layer that guards against photodegradation, yellowing, and brittleness. This protects the sheets from the harmful impact of UV radiation and helps to maintain light transmittance and quality for many years. Our products come with a 10-year warranty against loss of light transmittance. Upon special request, we can provide an enforced UV protection layer with a longer warranty.

Which of Palram's sheets are suitable for printing, sign & display applications?
+ -

For use in illuminated signage, PALSUN, PALSUN CS (Coil Stock) and PALGLAS are suitable for the sign face; and PALBOARD, PALOPAQUE, and PALIGHT for the body of the letters or symbols. For print & display, Palram's entire product portfolio can be used based on the specific application. This choice depends on a combination of several parameters, including the cost of the media, its durability, and its suitability for the specific application. Please visit Palram’s Flat sheet application catalog for more information.

Which materials can be used in the construction of my sign?
+ -

Sign faces are usually made from polycarbonate or acrylic. For extreme conditions such as heavy hail, low temperatures, or high temperatures produced when thermo-forming, polycarbonate is probably more suitable. For sign boxes or channel letter cans, PVC, multi-layered PVC and foam PVC can be used.

Which material diffuses the light better?
+ -

The diffusion is not defined by the material, but by the diffusion additive that is part of the manufacturing formula. The materials should be selected by their fit to the application (e.g. polycarbonate for thermo-forming or extreme weather). Usually products marked with sign grade and/or diffusion grades have greater light diffusion than others.