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Twinwall Polycarbonate Panel Storage and Installation Information

Storage Requirements

Polycarbonate Multiwall Sheets should be stored in warehouse areas not exposed to direct heat or light, which could make removing protective film difficult. Supported, sloped stacking is recommended, but sheets may be stacked up to 3' high on a flat, even supported surface.

Protective Film

Panels are supplied with a protective PE film which should be kept on until the panel is fastened. The UV-protected side is to be faced towards the sun and is marked with a white printed film, clear, or light blue film with a Sticker saying co-extruded thermoglazing.


Panels will not crack or split when cut or drilled. They can be cut using a circular saw with a fine tooth blade or a razor knife cut on both sides of the material. Compressed air can be used to remove dust from the channels.

All for proper expansion in all drilled holes. Do not drill within 1-1/2" from the edge of the sheet.

When fastening screws, do not tighten below the panel's surface.


Stiff fixing using adhesive or putty is to be avoided. If using a sealant, please get in touch with us for a recommendation.

Exposed top and bottom ends of a sheet must always be sealed using adhesive aluminum tape to prevent dust and dirt from penetrating inside the ribs. A proper polycarbonate "U" profile must be installed to protect the tape. Extruded ribs shall be installed in a vertical direction for drainage.

Glazing sheets should be joined by extruded polycarbonate profiles and be installed with their protective UV-stabilized surface towards the exterior. Please consult us for approved systems. Extruded polycarbonate profiles are available through us by special order.

Horizontal bars should be avoided. Larger lengths may be available upon request.

For proper application in roofing conditions, a slope of at least 5° is required.

It is advisable to drill small weep holes every 12 inches in the bottom "U" channel profile for condensation drainage. (To avoid damaging the aluminum tape on the sheets, drill holes in polycarbonate "U" profiles before installation.)


Panels should be protected from abrasion by the installer. After installation, panels should be washed with mild soap or detergent and lukewarm water using only a clean sponge or soft cloth, then rinsed with clean water. Fresh paint, grease, and smeared glazing compounds may be removed before drying by rubbing lightly with a good grade of naphtha, and isopropyl alcohol, followed by a final washing with mild soap or detergent and a final rinse.

Impact Resistance

Able to withstand extreme abuse, its impact strength is 200 times greater than glass and ten times greater than acrylic. Coextruded thermoglazing has the highest impact resistance among the thermostatic products used in the building industry. It will maintain its structural integrity even when exposed to elevated temperatures over a long time. On-site, it will not crack or splinter, assuring you a high degree of safety.

Resistance of Polycarbonate to Chemical Agents

Polycarbonate panels are resistant to some chemicals and products and non-resistant to others. Resistance can be affected by the chemical concentration, duration of exposure, degree of pressure, and temperature at contact time. Check with us for chemical compatibility.

Thermal Expansion

Allow for thermal expansion during installation at a rate of 1/8" per 3 feet at 100° temperature differentials in both the width and length of the sheet.

Bending Radii

Panels can be readily cold-formed to many bending radii and fabricated on-site to precise dimensions. It is important to avoid over-tensing the sheet; therefore, the minimum bending radius must be 150 times the thickness of the panel. Minimum bending radius = Ft./1 inch.


For proper point fastening, 1" neoprene bonded washers should be used with screws.

48" wide sheets should be fastened to supports at all four corners and points 6" from the edges of each purlin support.

This information has been drafted to the best of our knowledge. We reserve the right to change specifications and data without notice if necessary in these products' evolution. It is the sole responsibility of the customer to confirm with their architect, engineer, or another professional consultant that the materials offered for sale meet the requirements and specifications of the particular project and use for which they are being purchased.

Title: Twinwall Polycarbonate Panel Storage and Installation Information
Description: General Storage, Fabrication, Installation, Cleaning, and Fastening Information.
Published: 3/26/2009
Last Edited: 1/13/2023
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The information contained in this article is for general information purposes only. The information is provided by United States Plastic Corp. and while we endeavor to keep the information up to date and correct, we make no representations or warranties of any kind, express or implied, about the completeness, accuracy, reliability, suitability or availability with respect to the website or the information, products, services, or related graphics contained on the website for any purpose. Any reliance you place on such information is therefore strictly at your own risk.

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