Owning your own backyard greenhouse is an investment that can elevate your gardening experience beyond just providing a year-round growing space. A backyard greenhouse creates a slice of Costa Rica in the middle of a blizzard, it provides a natural therapeutic escape to stretch your green thumb, and can even be an incredibly convenient produce aisle providing you with fresh fruits and veggies. Whatever your desired purpose, designing your dream greenhouse starts with the decision of building with steel or wood and this article serves to shed some light on the benefits and drawbacks of each material.
If you consider yourself more of the creative type, choosing to build a wood greenhouse is great because it allows for more freedom in material sourcing and can easily be customized to fit your desired aesthetic. For example, wood greenhouses can be finished to match the color and siding of a house for an integrated look. You also aren’t limited to one type of wood, and based on your natural environment, something like Redwood may be more beneficial than say Pine or visa versa. Besides its aesthetic qualities, wood is also a great option because it is readily available and many contractors are experienced in building with it.
On the flip side, wood can rot when exposed to the moisture common in greenhouses. Organic materials like wood are also susceptible to mold and are great food for insects. One of the ways in which wood-frame builders keep lumber in their structures from deteriorating when exposed to high moisture is by using pressure-treated lumber. This kind of lumber is pressure soaked in a chemical compound. Chemicals like arsenic and chromium are common in this kind of procedure and can leach onto the plants in your greenhouse. This is something to keep in mind if you decide to go with wood.
There are other ways to ensure the structural longevity of your wood greenhouse. Painting and caulking the greenhouse slows the deterioration of the lumber. This process requires a bit more maintenance in the long run because the wood must be re-sealed and re-painted occasionally. Although, if you properly maintain your greenhouse, wood will make for a beautiful structure that will last for years.
If you choose to build with steel, your sourcing options are more limited but you will need less material because steel is stronger than lumber. For example, a steel frame will have fewer and smaller roof beams than a wood frame of the same strength. Fewer and smaller beams also mean easier installation because they lift into place easier. Fewer beams also mean less shading over your plants.
Although steel is impervious to insects, it does rust when exposed to water. Some steel buildings will use paint to retard the rust process. Just like wood frame greenhouses, these must be re-sealed and re-painted occasionally. Steel frames, however, can be galvanized, a process that includes adding a permanent, triple layer coating that is electrically bonded to the steel during the manufacturing process. This coating protects against rust better than paint while not deteriorating over time, requiring no ongoing maintenance. A steel-framed greenhouse will last you much longer than wood framed greenhouse.
Last but not least, your allocated project budget is often an important factor in choosing greenhouse materials. Steel frames often cost less than the lumber needed for the same residential greenhouse size. Steel frames can also save on installation costs because they are easier and faster to erect.
Wood and steel framed greenhouses each have their unique appeal and will provide a flourishing growing environment that you can enjoy year-round. If you are considering building a greenhouse in your backyard and would like more structural advice specific to your environmental, financial or personal circumstance.