Tips for Insulating the Foundation of Your Greenhouse

Building a greenhouse is a great way to ensure that you can grow beautiful flowers and fresh produce all year round. However, if you do not insulate your foundation properly you can end up spending a lot of money heating your greenhouse in the winter and moderating its temperature in the summer months. Fortunately, if you know what to do to insulate your greenhouse's foundation before you start construction the process is fairly simple.

Thermal Mass Definition

The philosophy behind insulating the foundation of your greenhouse is based on the concept of thermal mass. Thermal mass is a building material that is able to absorb heat from an external source, store that heat internally and then release it slowly over time. This is a great property for insulators for a greenhouse as it will absorb and store heat from the earth and from the sun during the day and then release it when temperatures dip at night and throughout the day. Concrete is a great thermal mass product.

What You Will Need

You will need several key items to insulate the foundation of your greenhouse. You will need sand, insulating foam, crushed rock or gravel, hardware cloth and concrete pavers. You have several options when it comes to the type of insulating foam that you use. If you are working with a small budget then you can use polystyrene foam as your insulator. However, if you have a larger budget it is a good idea to work with a higher quality insulating foam like PIR, which stands for polyisocyanurate foam, or PUR, which stands for polyurethane foam.

Insulating the Foundation of Your Greenhouse

The insulation process for your greenhouse is pretty straight forward. You will create layers that will trap, store and slowly release heat energy. You will start by excavating your foundation site. Next you will compact the ground and spread a one inch layer of sand. This will need to be leveled.

To help keep rodents and other pests out of your greenhouse you will next need to lay down a layer of hardware cloth. Then you can top this with your insulating foam. Add as much as is practical for your budget up to about 12 inches of foam. Top the foam with another layer of the hardware cloth to add another protective layer to discourage rodents and other pests. Then top with a few inches of crushed gravel or rock. Level this layer and top with concrete pavers.