Unlike a house, an insulated year-round greenhouse doesn’t need a finished floor. Most of a greenhouse footprint is used as a planting area, which means a level finished surface is not necessary. When choosing your greenhouse flooring, you will first need to decide how you want to grow in the greenhouse – directly in the soil, in raised beds, or in an aquaponic or hydroponic system.
Whatever your choice, make sure you insulate your greenhouse foundation so that the floor and soil below your greenhouse stays a stable temperature. Let’s go over the three different types of greenhouse flooring so you can decide which option is best for you.
If growing directly in the soil, your greenhouse won’t have a floor. You can use pavers, flagstone, gravel or wood planks to create walkways if needed.
Not finishing the floor of a greenhouse and planting directly into the soil offers several benefits for greenhouse growers. First and foremost, it allows for a more natural and holistic growing environment, as plants can access the native soil’s nutrients. This promotes healthier root development and enhances the overall vitality of the plants. Additionally, planting directly into the soil reduces the need for artificial soil mixtures or containers, which can save both time and money. It also enables better water drainage, preventing the risk of waterlogged roots and potential diseases. Moreover, the soil acts as a thermal mass (especially with the insulated foundation), helping to regulate temperature fluctuations within the greenhouse, which can be advantageous for maintaining optimal growing conditions.
Stone, pavers or gravel floors
Finishing your greenhouse floor with stone, pavers or gravel are some of the more popular options because they work well with raised beds. Most of our residential clients build raised beds that connect directly to the soil beneath the greenhouse (i.e. no flooring material beneath the beds). We recommend this so plants’ root systems can grow deeper into the soil below grade. We recommend creating walkways between the beds out of pavers, flagstone or crushed gravel.
The other option is concrete slab flooring.
This is a more popular option if growing with hydroponic/aquaponic systems, self-wicking beds, or on tables that need a durable and level surface. (However you can also create a level surface with gravel or stone). Concrete has a number of advantages:
- Growing beds or tables can be moved more easily if they are on wheels, such as the self-wicking raised beds in the photo, right. Wheelbarrows are also easier to handle on concrete.
- It can be easily washed down
- A concrete slab can also act as your foundation.
- You can still incorporate our Ground to Air Heat Transfer (GAHT®) system. The concrete provides additional thermal mass which helps stabilize greenhouse temperatures.
Having a concrete floor does come with a significant cost increase however. We recommend getting an estimate from a local contractor if you are considering a concrete slab.
- Like any material in the greenhouse, the floor needs to withstand high levels of humidity, and thus we don’t recommend plywood flooring.
- Drainage is important to think about. We often recommend installing a floor drain in any type of flooring.
If you’d like more information on flooring specific to your greenhouse project, Contact us!