In most cases, greenhouse kits include a constructed frame and a translucent material that encourages the sun’s rays, like 8mm twin-wall polycarbonate or our more durable 16mm five wall polycarbonate. The frame can be aluminum, steel, wood, and even plastic. So why do we make wooden greenhouse kits? We can think of quite a few reasons.
- Wood is more cost-effective than alternatives such as aluminum.
- Douglas fir is renewable and sustainable.
- Wood has a lower coefficient of thermal expansion than materials like aluminum.
- Wood experiences less dimensional movement with temperature changes.
In areas with high winds and heavy snows in the winter, a wooden greenhouse will prove to be more durable because of its weight. That, combined with the Growing Domes geodesic shape, makes them the best greenhouse for wind.
What kind of Wood are Growing Domes made of?
Struts: All 6 of Growing Spaces greenhouse kits are built with #1 Select Douglas Fir struts. We chose Douglas Fir because it is the strongest lumber, and is much less prone to warping or twisting. It is readily available in the US and Canada and harvested sustainably meaning that new seedlings are planted faster than trees are removed, ensuring that forests regrow.
Everything is cut to size, predrilled for both bolts and nails, and labeled. We do this all at our production facility so we handpick the best looking lumber and assure the highest quality. Pretty lumber is going to last longer than wood with imperfections, so beauty and strength come hand in hand.
A common question we hear is, why not redwood? Although redwood would be a good alternative, sourcing redwood would be difficult and expensive at this time. Despite supply chain issues with many products during COVID, Growing Spaces has been able to keep Douglas Fir in stock, keeping our projects moving forward.
Will it Rot?
Our Douglas fir is dipped in a non-toxic wood treatment called LifeTime® that keeps away moisture, resists mold and prevents rot. The treatment is friendly to plants, animals, and people. LifeTime® is different from a traditional wood stain in that the natural substances penetrate the wood fibres. It essentially petrifies the outer surface of wood to create a physical barrier against water penetration. You only have to apply one treatment of LifeTime® and never touch it again. LifeTime® can not be worn off, will not peel or fade and allows the wood to breathe and age naturally. Natural weathering actually increases it’s beauty and effectiveness.
Foundation Wall and Siding
We provide pressure-treated lumber for any areas that come in contact with the ground to prolong the life of the Growing Dome. This includes the bottom plates and vertical studs. The 2′ foundation wall top plates are made from treated Douglas Fir as described above. You can see the color differences in the pictures below.
The external siding is made from LP SmartSide®, a specific type of engineered wood that also has a long lifespan, resists termites, rot, etc. To enhance the aesthetics of the siding, we use a durable scratch-resistant pre-finish from Diamond Kote®.
The future of wooden Growing Domes & wooden greenhouse kits
Growing Domes were initially designed over 30 years ago in the Rocky Mountains of Colorado for dry and harsh climates. Since then, Growing Spaces has made continual improvements and adjustments to the design and structure.
As Growing Domes have spread across the globe, specifically to places in humid climates, there have been many requests for wood alternatives in our greenhouse kits. We hear you, and we are working on it. As I write this article, a team of senior engineers at the Colorado School of Mines is working hard on a project to develop aluminum struts. Once released, it would be available as an upgrade due to the high cost of aluminum.
In the mean time, if you do live in a high humidity environment it is important to control the humidity inside the greenhouse. We recommend adding additional ventilation, or using a dehumidifier or A/C unit.
Please contact us if you have any questions or concerns about our wooden greenhouse kit. With thousands installed all over the US, and in 14 different countries, we are confident that you will love your greenhouse for many years to come!
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I just purchased a 18′ unit. can’t wait to start growing
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