A lot of people ask what the best covering is for a greenhouse.  Here is a brief comparison of the three major types of coverings.  Also check out our Coverings Comparison Chart for more details.

• Polyethylene Film - At a cost of 10-12¢ per square foot, this option requires the smallest up-front investment and is usually the covering included with some of the least expensive hobby greenhouse options. The principal advantage of a polyhouse is that it is significantly less expensive than other coverings.

• The disadvantage of a polyhouse is reduced light conditions in winter and increased humidity compared to a glasshouse. They are prone to heat loss as well, since one layer of poly film has a very low insulating value. Also, a higher level of ongoing maintenance can offset the economy of this option since it can tear easily and should be replaced every 3-4 year

• Polycarbonate panels - At costs from $1.05 to $1.50 per square foot, this option is an excellent and very popular glazing option. While the initial investment is larger than polyethylene, it is much more permanent and maintenance‐free. Polycarbonate offers excellent light transmission, high insulation values, and durable strength that appeal to most greenhouse owners. There are two types of polycarbonate covering for a backyard greenhouse:

-Single Walled Polycarbonate
• This  rigid plastic glazing material approaches glass in clarity and light properties.
• Light transmission value of up to 92%.
• Easily installed, lightweight and can be cut with utility knife or tin snips.
• Virtually unbreakable which makes it extremely resistant to hail damage.
• UV protected outer surface to provide long life under high sun conditions.
• Single wall provides little insulation, which can be a factor in heating costs.

-Multi‐Wall Polycarbonate
• Tough impact strength for resistance to hail. • Provides insulation value similar to insulated glass.
• Reduces heating costs.
• UV protected outer surface provides long life under direct sun.
• 10‐year warranty against yellowing and loss of light transmission.

• Glass panels
  • At $3.50 to over $7.00 per square foot, glass is by far the most expensive option in greenhouse glazing. However it is a worthwhile, long-lasting, and beautiful glazing option for many hobbyists.
  • The main benefit of glass is that it is the longest lasting covering option for greenhouses. When properly installed, glass glazing will last for generations. However, even tempered glass can be cracked or broken.
  • Glass is also very aesthetically pleasing and can offer a classic look that no other covering can offer.