Materials for Building an Inexpensive DIY Hoop House

Using the Right Materials to Build Your Hoop House

Before you get ready to build a DIY hoop house, we recommend you get a good grasp on what materials are best for the build. Read about the pros and cons of different building materials that are used to create DIY backyard greenhouses, high tunnels, and hoop houses. Learn about the different types of maintenance that will be required for hoop houses constructed from various materials. Decide what materials you want to use for your hoop house project. 

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Watch this video where we discuss many of the common building materials used to build a hoop house.

What are the Best Hoop House Options?

There are a few common hoop house greenhouse building materials considered for the construction of DIY hoop houses. There are benefits and detriments to each material for building a hoop house. Hoops are made from either metal or PVC pipes. Hoop house hip boards and baseboards can be made from metal or various types of wood. The structure is then covered by UV stabilized hoop house plastic.

Using PVC Pipes to Build a High Tunnel

PVC pipe is made from polyvinyl chloride. It is commonly used for both electrical applications and cold water supply lines. PVC pipe is not a terribly strong material and is prone to bending when exposed to heat. The main reason people choose to use  PVC pipe when building a high tunnel or hoop house is the low cost associated with the material.   

When used for building a hoop house or any other application where it will be covered with the plastic it must be painted. PVC pipe and plastic are not compatible materials. PVC will degrade the plastic when exposed to UV rays. Using PVC directly against polyethylene plastic will void the warranty on your plastic. 

Using EMT to Build a Greenhouse

EMT or electrical metallic tubing comes in narrower sizes than fencing or rolled pipe. It is also a different strength of the metal. It contains more lead to make it malleable since it is used in building houses where the tubing may need to be bent to make multiple 90 degree turns. EMT tubing can be a valid choice for smaller hoop house structures but will be extremely flexible in hoop house structures over 10’ wide.

Building a Hoop House with Top Rail

Top rail is named for its use as the top rail of chain link fencing. These are typically sold in 10’ 6” pieces that are swagged on one end to fit easily into each other. The top rail fencing sold at most big box stores can vary in gauge. We have seen 17 and 18 gauge sold but nothing as strong as 16 gauge rolled steel pipes like those used to build our all inclusive All-Metall Greenhouse Kits. 

Top rail is a good choice for many DIY projects as it makes a nice compromise between price and quality. For a hoop house or a greenhouse under 20’ in width, it is strong enough to withstand a decent amount of snow and wind load. 

Rolled Steel Tubes for Building Hoops and Ridge Poles

Pipes made from 16 gauge, or stronger, rolled steel are the high strength, high-quality choice for building hoops and ridge poles in any hoop house. Particularly for those 20 feet or more in width, stronger steel is better.  

Bending Your Own Hoops for a DIY Greenhouse Build

If you will be bending your own hoops for your build you can either build a jig or use a specialized tool like our heavy-duty hoop bender. Any of the materials listed above can be used to make hoops to support greenhouse plastic but top rail fencing or rolled steel tubing are the best choices. For more information on bending different hoop house widths, you can read this article from our blog on Bending DIY Hoops.

PVC Pipes for Hoops

• STRENGTH greatly reduced by UV exposure
• Heavy and sustained winds can push a PVC structure to failure.
• Compounded expenses later in the cost and time to rebuild the structure

*Bootstrap Farmer recognizes the need to start on a strict budget but encourages anyone considering this route to do their research.

Electrical Metallic Tubing for Building Hoops

• The thin walls of this material do not give you a lot of strength to work with.
• EMT makes great individual bed covers for microclimates
• Best for smaller projects

Bootstrap Farmer All Metal Pre-bent Hoop House Kits

• Stronger gauge metal than available top rail fencing
• Double galvanized, zinc coating, and proprietary coating from Flo-Coat® 

* Up to 5X the corrosion resistance of cheaper metals

Types of Woods Used in Building Hoop Houses

Many DIY hoop houses use wood for baseboards and hip boards as well as endwalls and doors. Any wood used in hoop house style greenhouses is going to be exposed to moisture and extreme temperatures. Depending on your location the types listed below may be easier or more difficult to access. We DO NOT recommend using pine if you can avoid it. Likewise, plywood is not designed for outdoor exposure and will break down much faster than expected due to moisture dissolving the glue. 

Cedar 

All types of cedar will hold up well under elements. It is insect resistant and stands up to water relatively well.

Redwood 

This is extremely good for use with constant moisture exposure. It is also insect resistant and long-lasting. Redwood can be difficult to find and expensive outside the west coast. 

Cypress 

Many types of cypress hold up well, similar to cedar, and are sometimes available in areas where the other types are not common. 

Pressure-treated lumber 

Treated lumber is water and insect-resistant. Most people avoid using it near growing food or play structures because of chemical leakage.

When Using Lumber on Your Hoop House Build Ongoing Maintenance is Required 

Depending on the materials you use, ongoing maintenance may be required. If you use lumber for parts of your structure it will eventually need to be replaced. No matter which type of wood you choose, if it is in a moist environment it will rot over time. You will need to remove your plastic and your lock channel in order to replace the lumber. 

Read this article on Hoop House Maintenance including caring for your greenhouse plastic and other routine maintenance.

Comparing Greenhouse Kits Based on Strength of Materials

As we discussed in Are You Ready to Buy a Hoop House, there are several factors that can be tricky to compare kits from different companies. It is important to consider the strength and reliability of the materials when comparing kits. One hoop house kit may be less expensive using a weaker gauge of steel while another may be priced slightly higher but provide extra strength in materials. 

Building Materials Not Included in a Hoop House Kit

When purchasing any kit but particularly a DIY kit is vital to confirm which items are included vs. which will need to be purchased locally. Many kits do not include the hip and baseboards. You can choose to build these from lumber or purchase metal hat channels to complete these. Some kits will include all of the hardware that you need while others will just provide a list for you to purchase. 

Building Solid Endwalls

Some people choose to add solid endwalls to their DIY hoop houses using polycarbonate sheeting, corrugated metal or lumber or by buying premade kits. If you will be building solid end walls for your hoop house we highly recommend using materials that will stand the test of time. Using the best materials you can afford will reduce maintenance costs and labor over the long term. 

Hardware Needed for Hoop Houses

We recommend using hardware that is the same as the material you will be building your hoops from or at the least has similar corrosion resistance. Galvanized or zinc-coated is best. If you buy a kit from us the galvanized hardware is included. The hoop house will flex in the wind so the shear strength of your hardware is important.

Build the Best DIY Greenhouse that You can Afford   

Good Information When Shopping for a Greenhouse

When shopping for a greenhouse, it is important to recognize and understand the differences in design, When shopping for a greenhouse, it is important to recognize and understand the differences in design, quality, and price before making your decision. There are all types, styles, and qualities of greenhouses available on the market today. Each version has its purpose and market. One version is not “better” than the other, rather, “different”. An apple is not necessarily better than an orange, it’s just different. However, when comparing one apple to another apple, one may very well be better.

Contact us to discuss your requirements of Steel Greenhouse Pipe. Our experienced sales team can help you identify the options that best suit your needs.

A greenhouse is simply an enclosed environment that can protect plants from the elements. A 10’ x 12’ greenhouse can cost anywhere from $200 up to $20,000 depending on the quality, design, aesthetics and overall purpose of the greenhouse as required by the customer. Even in larger sizes, the same is true. There are greenhouses made of plastic tubing and plastic or vinyl covering, to wood frame kits covered in polycarbonate to the prefabricated and manufactured greenhouses from extruded aluminum and glass.

The greenhouse “kit” market offers an array of low cost relatively attractive greenhouses that can be found online and in many home building supply outlets. These are quite functional and inexpensive. However, they are very lightweight in their design, and could very easily sustain considerable structural damage in a strong storm with high winds. This is because the actual thickness of the extruded parts is minimal. These typically don’t come in larger sizes because of the spans.

Then there are greenhouse structures that are a step up in durability and sizes. Heavier extruded parts allow for this. These will typically have individual vent panels at the ridge that open automatically with gas-expansion type lifters. Once again, relatively economical but still limited in overall quality and strength. Again, these are numerous and easy to find online.

Stepping up quality and design

Now we go from apples to oranges. These greenhouses are set apart from the “kit” style greenhouses in that they are designed for long term function, strength, durability, and beauty. There are fewer manufacturers of these types of structures, with only a handful of manufacturers in the US. These greenhouses are usually a long term investment. While cost is a relative thing, these greenhouses are considerably more expensive than the kit versions. The quality and degree of design are much greater.

Heavier extrusions, full-length ridge vents, taller eave height, wider and longer sizes are usually standard in these greenhouses. A major difference is that most of these incorporate a set of “sub-structures” inside the greenhouse which greatly adds to the overall support and strength of the structure. The sub-structure also plays a part in the operation of the full-length ridge vents’ operation. The height of the greenhouse, as well as the full-length ridge vents, provide better conditions for circulation, air replacement, and cooling – all important to the serious grower.

When comparing “oranges to oranges”, it is important to recognize the differences in order to determine which orange is the best. Within the same family of greenhouses – that is – same general type and structure, there are still significant differences that may set one apart from the other. This is usually reflected once again in the price. It is very difficult to see the differences in a catalog or website picture. They all look beautiful! However, a closer look will explain the differences and why two greenhouses that look identical in a picture could vary in cost. Things to look for:

1. Full-length ridge vents

Full-length ridge vents can be operated manually or automatically controlled by a thermostat.

2. Substructures

These are the channel or I-beam assemblies that are inside the greenhouse and add substantial support to the entire structure. These can be of steel or extruded aluminum. One is as good as the other in function, however, steel has to be galvanized to prevent rust, or if painted, there is a good chance of rust in the future. Aluminum has the same appearance as the rest of the greenhouse whether in mill finish (its natural color) or painted. Rust is never an issue.

Both steel and aluminum can be sized for particular load requirements.

3. Bay spacing

A bay or “row” is typically the space between the glazing bars running vertically. You may not notice it in a picture, but bay spacing varies greatly between manufacturers. The wider the space = a less number of glazing bars. The less number of glazing bars = a less number of assembly holes to be punched in the sill, purlins, eaves, and ridge vent assemblies. This reduces the cost of materials and fabrication time which reduces the final purchase price of the greenhouse. In reverse, the closer the spacing equals more glazing bars equal more material and fabrication time which equals higher purchase price. Where it may or may not matter to the buyer, the closer bay spacing equals more glazing bars equals added strength. The wider the bay spacing equals less glazing bars equals reduced strength.

4. Purlins

Purlins are the members that run horizontally down the length of the side wall, roof and across the end wall. These are attached to the sub-structures and support the vertically running glazing bars. More purlins = more attachment points to the glazing bars = added strength. The number and location of the purlins can also increase or decrease the aesthetic appearance.

5. Fasteners

Screws, bolts, and nuts – all needed to assemble the greenhouse. Greenhouse companies use a variety of stainless, zinc plated or aluminum. Stainless is the most ideal, as it won’t rust and is stronger than aluminum.

6. Built-in and free-standing benches and shelves

Benches are offered in a variety of materials; wood, aluminum, galvanized metal, composite and /or a combination of all. Built-in benches use the interior greenhouse frame as the back supporting portion of the bench or shelf. This makes for very stable construction. Compare the materials the benches are made of when comparing prices. The size of the material in the framework as well as the bench top material. Aluminum is ideal since it does not rust or decay. An aluminum grid or expanded panel is ideal because it will not rust, and it allows for good air flow and drainage to potted plants. Galvanized materials are good as well. Lighter weight construction is offered also. Smaller or lighter framework with hardware cloth tops (wire mesh). This works effectively, however may have some limitations as to the size and weight of potted plants.

Aluminum framed benches and shelves can easily be constructed from similar extrusions used in the greenhouse and can easily be painted to match the greenhouse finish. The tops are typically left in mill finish.

7. Evaporative cooling

Evaporative cooling is an essential part of the greenhouse function for the more serious grower. This, along with heating for the colder months, will enable you to use your greenhouse year-round. An evaporative cooler is simply an enclosed fan unit which draws air through wet pads and blows the cooled air into the greenhouse. The bottom of the cooler holds water which is pumped up and dispersed to the pads on three sides of the unit. The water trickles down through the pads, cooling the air slightly. As the cooler air is introduced into the greenhouse at roughly bench level, the warmer or hot air is displaced upward (hot air rises). The most efficient place to remove the hot air or allow it to escape is through the ridge vents; the highest point of the greenhouse. This “air replacement” with cooler air is what keeps the greenhouse from being a hot box. This along with some type of roof shading make for a very comfortable working and growing environment inside the greenhouse; even on a 100-degree day with high humidity. Some may disagree, but it’s true.

The control panel of the cooler is usually framed into the glass greenhouse end wall – opposite the door on typical back yard greenhouses. The quality of a cooler installation can vary from good to bad. Frame kits and installation kits are essential for a proper installation. This allows the cooler to be easily removed or replaced if need be. Stands are optional depending on the distance between the ground and bottom of the cooler. The cooler should be up and off the ground by at least 3-4 inches. This allows for draining the cooler. The drain is located in the bottom of the cooler.

8. Overall design

There are several factors that go into the design of a greenhouse that can make a significant difference in the final product.

• Ease of assembly: If doing the installation yourself, this can be a big factor.
• Aesthetics: How the purlins line up with the glass junctures or the benches will affect the final appearance? Thought out clean lines of the design.
• Ease in custom modifications: How does the factory look at custom sizes or designs? Are you getting exactly what you want from your salesman?

9. Labor and installation

As in most cases, dealing with hired labor can vary from being a terrible to a great experience. It is no different in the greenhouse industry. The quality of the greenhouse, the installation and the customer satisfaction is only as good as the quality of people you hire to do the work. This can also be reflected in the price being charged for the labor or in this case, the installation of your greenhouse. Price for labor is a relative thing. It can vary greatly. Sometimes with good reason, sometimes not. It is good to question your dealer or salesperson as to the qualifications of the installers. The ideal installers would be those who work full time in the greenhouse business, either in sales, manufacturing or a combination of both. Age and experience at least in the leadership role of the installation crew is also a plus. The crew will vary in size according to the size of greenhouse being installed. It can vary from 2 to 4 to 6 men.

Again, experience and knowledge trumps number of workers.

Everything else being equal, the installation is what will impact you the most in the overall experience of fulfilling a dream to own a quality greenhouse. Price should be an important factor, but not necessarily the deciding factor.

It is good to know some detail about what you may be purchasing. Ask more questions of your dealer or salesman. If he or she says “Ours is better”, ask for an explanation. Why is it better? The better question is, “All things being equal, what sets yours apart from others?”. Any good salesman should be happy and able to quickly provide an honest answer. Ask first, before offering your knowledge. This will be a good indication of what the greenhouse company is used to doing.

There are even more expensive greenhouses on the market, usually much higher in cost, mainly because of ornate design for luxury and elegance.

I hope this information has been helpful. Please call with any questions you may have. Thank you.

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