What Is Difference In Benders?

The most often ask question...

What is the difference between the DY, the C, and the PF series benders and why are there different series?

The tubing being bend is 10ft or 10ft 6 in. long. A bending stroke last about 12 seconds for most people, regardless if you are bending 15 inches per stroke on a DY or 36 inches per stroke on a C or 84 inches on the PF. Bending hoops for hours on a DY will wear out even the strongest person, the fatigue is lessened on the C series and dramatically reduced on the commercial PF series.

The PF Series was my first bending tools to be offered to the public, it was for fast hoop production on a daily basis. I invented these tools and along the way I discovered that many homeowners wanted to bend their own hoops for a small hoop house and our PF series was simply to costly for them just to be used for three hoops. So I came out with the DY series for the home owners, "with great success" these are the most copied (in one form or another of my bending tools). Still there was a group of customers left out, "the small truck farmer, small plant nursery etc. They needed faster bending than the DY but not on a daily basis, enter the C series.

Will These Hoop Benders Bend Different Size Hoops?

Our bending tools are fixed radius and are not adjustable for different hoop sizes. Example our 20 ft. benders will produce a complete 20 ft. circle when six 10'6" lengths are bent and joined together and compressed. with that in mind bending only three lengths produces a 20 ft. wide hoop about 9 1/2 feet tall when compressed and installed into ground stakes.

With that said, you can make a usable 16 ft hoop using a 20 bender by simply bending less tubing 2 and 1/2 sections instead of 3 sections into the same radius. The bottom ends of the hoops will be pointing outward a little, then will not be going straight into the anchor pipes. Therefore the anchor pipes must be set in the ground at an angle to match the hoops.

Do Your Benders Make Straight Sidewalls?

Our benders are not used to produce straight sidewalls. Traditional greenhouses/hoop houses are anchored into the earth using larger anchor pipe/tubes. Usually with this type tubing the anchor stakes only project about 6 inched above ground level then the hoops are inserted into these anchor tubes six inches and bolted. To raise the hoop house taller simply use longer anchor tubes that will extent high enough to achieve the finished height you desire.

Remember that these are hoop houses and the taller it is raised the more wind load the structure will have to withstand. Typically a 12 ft. wide or less round hoop house can be raised an additional four feet, producing almost a 5 ft. straight side wall. A 20 ft. wide hoop house can be safely raised an additional 4 ft. if using 15 gage or better ground post anchors.

Remember a little common sense can prevent a lot of headaches later on. To get a feel of how much wind force is applied to a four ft. straight sidewall, wait for a fairly windy day and hold a 4' X 8"sheet of plywood facing the wind. So if you have a 24 ft. long hoop house with an additional 4 feet in height, that force is three times as much.

NOTICE: This comparative is for a general example, and not to be attempted. We are not responsible for injuries sustained by individuals, or property attempting to try this wind load example.

What Is The Recommended Hoop Spacing?

Nominal Hoop spacing is 4 feet O.C. on typical greenhouse/hoop-house construction , however you can space them closer if you like. On some applications such as summer shade or bird net structure applications 6 ft is acceptable provided the covering is removed before the winter season.

Typically greenhouse lengths are based on being divisible by 4 (feet spacing) For instance if you planned to build a 42 long greenhouse, consider going to 44 or even 48 feet. The longest greenhouse are normally 96 feet long this is because the poly typically comes in 100 ft. rolls and your poly must be longer than the house.

What Size Poly Covering Do I Need?

Measure up from the ground on one side up and over to the ground on the other side, then add 2 feet to that measurement, let’s say it measures 29 feet, then you add 2 feet to that measurement, your poly must be at least 31 feet wide.

Next measure the length of your hoop house and add 2 feet to that measurement, ground to ground it’s 40 feet long so adding 2 feet to that your poly covering must be at least 42 feet long.

To cover the top of your hoop house you will require at least a 31’x42’ sheet of poly.

For the ends measure the width of the hoop house and add 2 feet to that. Then measure the height in the center and add 2 feet to that. these numbers are the minimum required to cover each end.

Most of our hoop designs can be covered either 6 mil, 24 ft. wide or 32 ft. wide poly, both of which we stock in long rolls and stock many different precut lengths of both these widths. This is standard 6 mil Nursery grade UV resistant poly

We also stock 4 mil in 12 foot widths for low tunnel applications

Can I Bend 21 ft. Lengths Of Tubing?

I’m often ask “Can I bend the 21 ft lengths without cutting them in half?” The answer is yes, but don’t try it. It seems that most people think that it would be
faster to skip the cutting them in half to 10’6”, and just bend the full 21 ft length. First of all controlling a 21 ft length of tubing while bending it is to say the least a nightmare and will 99% of the time end up in disaster and a very long wine bottle cork screw. Most factory made hoops are made using 10’ 6” or shorter lengths.

Will I Need To Heat & Cool My Greenhouse?

Greenhouses are a space to create as close as possible the environment required for your plants to flourish and produce healthy plants.

You must heat your greenhouse if your plants require warmer temperatures than the current inside temperature of the greenhouse or cool the temperature if it is too high.

Remember you must create as close as possible an artificial environment the plants normally thrive in. This also includes providing the correct amount of light or shade. Putting shade over plants to help cool them is very bad for plants that require full sun (put a tomato plant under shade will result in a sick or dead plant).

The reverse, putting plants in full sun in winter to heat them can also be bad thing to do, ( putting a fern in full sun to warm it produces bad results in most cases).

Bottom Line! Study your plants requirements, in greenhouses that are used to over winter house or patio plants and there are usually many different types of plants too sheltered you must find a medium, some made be set back a little while others slow down a little but still thrive, all will rebound and return to normal when returned to the patio and house.

Double Poly Covering; Pro's & Con's?

Purpose: Insulation value added by creating an air void between two separate layers of poly covering.

PROS: Effectively slows heat loss in winter and heat gain in summer. Its cost effectiveness depends on several factors. #1 Plant requirements, heat, light etc. #2 Average winter ambient temperatures. #3 Reduces wear of poly by buffering the wind (the inflated outer layer act as a shock absorber)

Cons: #1 The addition of a second poly layer decreases light penetration and may cause adverse effects in plants. #2 Additional cost may not be justifiable for certain plant applications.


When over wintering plants or early grow out stages at lower temps say 55 degrees in a climate having a milder winter or summer avg. double poly is questionable as to cost effectiveness.

Many beginners into greenhouse growing focus on saving on heat such as double poly covering or installing shade cloth over their plants in times extreme heat; without first focusing on the growing requirements of the plant they are growing. Altering the environment can end in great disappointment for those that fail to understand this

A Greenhouse is a structure where as an Artificial Environment is created that is Optimum for plant Growth. It can be either for short term season extender or long term plant production. Understand that any and every component that is added to the structure will change the environment so always consider the effect on your plants before proceeding.