5 panels - ThermaGlas 4mm Clear Twinwall Polycarbonate Panel

5 panels - ThermaGlas 4mm Clear Twinwall Polycarbonate Panel


$194.00 Regular price
  • In stock - departs in 2-3 business days

ThermaGlas 4mm twinwall clear polycarbonate, in 2' x 6' panels, are perfect for use as replacement panels for hobby greenhouses.

These ThermaGlas polycarbonate panels offer 99.5% UV protection. The light weight and shatterproof multiwall design coupled with integrated UV resistant co-extruded layer yields long service periods backed up by a 10 year limited warranty. The cellular multi-layer structure reduces heating costs in winter while minimizing excessive heat in summer. A special coating on the bottom side eliminates condensation dripping. Blocks ultraviolet rays that burn plants and living tissues, and transmits only beneficial radiation.

  • 2' x 6' panel
  • 4mm Thickness for double wall
  • 82% light transmission
  • Superb thermal insulation—saves energy
  • 10 year limited warranty against UV degradation
  • Impact resistance—virtually unbreakable
  • Approx. Weight: .16 lbs per sq. ft.
  • Low flammability (available with CC1 rating)
  • R-Factor: 1.49; U-Factor: 0.67


Volume pricing available for large quantity orders. Email Us or call a representative at 1-888-281-9337 to place quantity orders. Purchase orders are accepted from schools and institutions.

Additional Information

ThermaGlas Assembly & Storage Guide (PDF)

Multi-wall Polycarbonate Installation Instructions (PDF)

ThermaGlas Technical and Installation Guide (PDF)

ThermaGlas Limited Warranty (PDF)

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Customer Reviews

Based on 3 reviews
Greg Hidley (Los Angeles, US)
polycarb panels to rejuvinate harbor freight greenhouse

After trimming to size, the new panels worked perfectly.

K Herbert (The Plains, US)
Poly panels

I have a small green house and after a big windstorm, one panel blew out and cracked. Replaced it with these panels and it worked great. I had to trim to size for fit, but it works and looks great. Thanks!

Legacy Review
Exactly what I needed

I bought a cheap Chinese greenhouse kit. When I assembled it, I found some of the panels to be narrower than specified. When a wind came up, several panels blew out. 4-mm replacement panels of sufficient length were hard to find, but Greenhouse Megastore had them. They are the correct width and they fit as they should. If I need more replacement panels in the future, I will check Greenhouse Megastore first.