What is Better to Build a Glass or Polycarbonate Greenhouses?

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Which is the Best Choice, of Greenhouse Building & Construction Planning, Glass Greenhouse Plans or Polycarbonate Greenhouses Plan?

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Post Category: Greenhouse Articles > Building Greenhouses > Greenhouse Components & Parts > Glass and Polycarbonate > Material and Cost Comparison

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Greenhouses are classically made from aluminum and glass, but recently, some people are substituting the glass for twin wall polycarbonate.

• The mega trend toward producing your own vegetables is leading more growers to experiment with different materials and expand beyond traditional options.
• Plastic greenhouse construction materials include fiberglass, polyethylene film, and polycarbonate.

Polycarbonate has numerous advantages over glass, including:

1. Greenhouse Insulation Ability:

Successful greenhouse plant growing is a matter of keeping the plants at the right temperature.

• Glass is not a very efficient material when it comes to heating, because it transmits heat and cold too rapidly.
• People have made use of glass’s difficulty retaining heat in other structures, from thermometers to spoons, but it is a disadvantage in other areas.
• Greenhouse glass panels are usually double or triple the normal thickness of glass to provide enough insulation, which can be problematic.

Polycarbonate

At the right thickness, polycarbonate sheets retain heat better than horticulture glass.

1. Polycarbonate sheets can lengthen the plants’ growing season, which can make all the difference in plant production.
2. Twin polycarbonate sheets are structurally similar to thermal windows, and provide a similar benefit.
3. They can reduce heating costs when compared to glass-paneled greenhouses, due to their greater heat retention abilities.

A material’s thermal insulation value is its ‘R’ value: Horticulture glass that’s three millimeters thick has a lower R-value than four-millimeter twin-wall polycarbonate sheets.

Single layer polycarbonate sheets have a reduced R-value compared to glass, so it is important to take grades and measurements into account, and not to substitute single layer polycarbonate sheets for twin layer polycarbonate sheets.

• A higher R-value can make all the difference for the plants, particularly when growing during the autumn and winter.
• The R-value will increase in proportion to the thickness of the twin panel polycarbonate walls.

 

2. Greenhouse Structural Durability:

Glass is famously fragile. 

1. Polycarbonate sheets can withstand far more pressure and shocks than glass, including fallen tree branches, hail, heavy storms, and the impact from incoming tennis balls.
2. Growers with nearby trees, active wildlife, or bustling neighbors may want to invest in polycarbonate sheets.
3. Twin polycarbonate sheets are also highly flame resistant, in case of emergencies.
4. On average, twin polycarbonate sheets last for fifteen years under ideal conditions.
5. Greenhouses made from glass require substantial repairs over the course of their own lifetimes.

 

3. Ease of Greenhouses Assembly:

Polycarbonate sheets are not as heavy as glass, and do not have to be cut specially to fit the greenhouse specifications. 

Glass is heavier than many other building materials, and needs the sort of significant framing structure polycarbonate sheets do not. Glass also must be kept completely rigid during construction. Often times, amateur growers cannot construct glass greenhouses themselves, and must procure the services of a contractor. Polycarbonate sheets are more conducive to individual assembly.

 

4. Internal Light Penetration:

There is a risk of burning plants when using glass-paneled greenhouses, because glass does not effectively diffuse light.

1. Polycarbonate sheets are constructed to have a ribbed texture that breaks ultraviolet rays.
2. The texture of polycarbonate sheets diffuses the incoming ultraviolet light, all the better for plant growth.
3. The diffused light minimizes shadow, so growers can take full advantage of incoming light and not have to compensate on behalf of the plants.
4. Some plant species need more or less light, and could be most efficiently grown in a greenhouse made from twin-walled polycarbonate.

 

Materials: Made with Glass

5. Reduction in Inside Greenhouses Condensation Levels:

Twin polycarbonate sheets have been tested in conditions of eighty percent humidity, with a fifty degree temperature differential between the outside and the inside of the greenhouse.

1. There was still no condensation on the greenhouse glass. 
2. Greenhouse condensation is more important in regards to aesthetics, but a buildup of moisture can still be problematic.

Greenhouse Materials: Made with Polycarbonate and Plastic Roof

Glass Greenhouse Panels: Materials

Glass Hot House: Sun-room Greenhouse Conservatory Elegant Style

Basic Hobby Greenhouse: Built with 6mm Twin Wall Polycarbonate Panels

EarthCare Greenhouses Brand: Basic Hobby Greenhouse 6' x 6' Kit w/ 4mm Polycarbonate

 

Growers can also take advantage of both materials, and get greenhouses constructed from a combination of glass and polycarbonate.

• Some growers still prefer glass greenhouses for sentimental reasons.
• Advances in materials science will create a portfolio of options for greenhouse growers and hobbyists.

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Greenhouse Articles & Reviews: HomePage Brought to You By: Mini Greenhouse Kits  

 

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What Are Cold Frame Greenhouses?

Cold frame greenhouses can be the ideal way for a regular person the have their own greenhouse, no matter where they live or budget.

A cold frame greenhouse is the most basic protection of your plants or garden.

• Because they are made from a simple wood or PVC plastic frames with a clear thin material for the roof.
  
• This doesn't necessarily mean they are cheap and won't hold up to the first change in the weather, these are made from a variety of materials that are meant to last.

While you can buy some cold frame green houses that are small enough to come fully assembled, larger models are best purchased as a kit.

• While the DIY person can buy plans and create one on their own, many who want a greenhouse want to be able to get it up fast.
  
• A kit comes with everything you need to build the greenhouse, and depending on the kit may come with lengths that are already cut, and the holes for the hardware already drilled.
  
• It really depends on how large the greenhouse is, and how much you have to spend.

One of the nice things about buying cold frame greenhouses in kits is that you can choose from many different options.

1. You can have vents if you want, and some of the basic models come with solid doorframes, or zippered closures on the ends.
   
2. You can also get mounting brackets for lighting panels, it just depends on the retailer.

There are some drawbacks to cold frame greenhouses.

1. Some of the materials are non-rated buildings, and most are not able to deal with heavy snow or high wind areas of the country.
   
2. For these either a more expensive kit is recommended.
   
3. Another couple of things you may consider when you buy these greenhouses are that you should make sure you don't need a building permit, and call the cable and other utility companies to come and check for underground lines.

While you can put up cold frame greenhouses on any level surface, it is recommended that you put in an edge foundation or at the very least put the posts three feet into the ground. Ideally, if you are going to put the structure into the ground that the holes are filled with concrete.

There are many different companies that sell cold frame greenhouses online.

• It is important that you visit these sites carefully because prices can vary greatly.
  
• The first thing you want to do is measure the space you are going to need to cover, and then account for the height.

Go to some of these sites, look around for what kinds of different materials they offer, their pros and cons, and then choose the one that fits your needs and your budget the best.

• If you really can't decide, then choose the one that offers free shipping, and the one that has a warranty on their products.
  
• Whichever retailer you choose, make sure they offer a double layer of covering, with UV protection, so you don't have to change out the poly film as often.
• The best place to buy cold frame greenhouses is from Mini Greenhouse Kits, their selection and prices are unbeaten by all, and they have the highest quality products on the market, guaranteed.