Foundation Wall

The foundation wall’s bottom plate and studs are crafted from ProWood® (safe, pressure-treated lumber) to enhance its durability. This lumber is resistant to rot and termites. ProWood holds the Gold GREENGUARD and NGBS Green certifications, and its wood treatment is recognized as a certified Environmentally Preferable Product. Most building departments mandate the use of pressure-treated bottom plates for all structures, and the ProWood employed in the foundation wall meets or surpasses these requirements.

To further safeguard the 24-inch foundation wall, the interior of the greenhouse is lined with galvanized sheet metal.

The Growing Dome comes standard with LP® Smart Side® panel siding, which is durable, easy to install, and aesthetically pleasing. This siding material resists rot and termites, and it can withstand extreme weather conditions such as hail, heavy rain, snow, intense heat, and freezing temperatures.

Soil, similar to water in the above-ground pond, serves as a valuable source of thermal mass. In our year-round greenhouses, the insulated foundation wall prevents the soil in the growing beds from losing heat during cold winter nights.

The 15′ – 26′ Growing Dome features a 2″ x 4″ foundation wall that provides sufficient space for insulation with R-10 2″ polystyrene foam board. On the other hand, the 33′ and 42′ Growing Domes utilize 2″ x 6″ lumber for the foundation wall, allowing for the insulation of the wall cavity with two pieces of 2″ insulated foam board. Each kit includes spray foam, enabling proper filling and sealing of any insulation gaps.

After constructing the dome, you can opt to add a perimeter frost barrier. This barrier prevents permafrost from seeping under the Growing Dome Greenhouse during winter and helps keep water away from the foundation.

Our greenhouse installation instructions will guide you through installing polystyrene foam board sloped away from the dome around the entire perimeter. After installing the perimeter insulation, it’s advisable to cover it with gravel, bark, or decorative stones. These materials will prevent dirt and water from splashing onto the siding, thereby enhancing the appearance and longevity of your dome.

In more temperate climates, such as California, Arizona, and regions without severe ground freezing, you can skip this external perimeter insulation option.