Building a Greenhouse Foundation

There are many choices at your disposal when it comes to building a greenhouse foundation. Some folks, especially if they are buying a prefabricated kit, will simply lay the greenhouse floor over whatever ground exists whether that chosen location is gravel, dirt or grass. Indeed, some pre-made greenhouses come complete with not only roof and walls, but also a floor, as well.

If you opt for diy greenhouse construction, it is advisable to prepare the ground underneath it in some way. This could be as simple as smoothing the ground and laying down railroad ties spaced an inch apart. An alternative solution would be to create a simple platform of eight-foot two by four’s or one by sixes nailed to four by fours spaced out about every eighteen inches under the slats. That way you not only have a solid base but also drainage as well.

However, those simple designs leave you with the problem of controlling weeds, replacing floorboards, controlling mold along with other issues connected with wooden bases.

Building a greenhouse foundation with concrete, similar to the type that many houses are built on,  is the next step up. Construction of this type of floor is much easier that it may sound. However, it does require a lot more effort and there are some possible drawbacks.

Constructing a concrete base for a greenhouse requires laying out an area, smoothing it and building a temporary container around the area you intend to pour. You will want to make it reasonably smooth and level. Unless you have had experience at pouring cement, you may find leveling and smoothing a little challenging.

Ultimately, you will be left with a semi-permanent foundation, which would be difficult to move or remove later on if you change your mind about the location.

Nevertheless, a concrete base will last longer and give you some options regarding heating. For instance, you could lay carpet or tile on top of the concrete with heating tubes or wires in between. Cement floors as well as being sturdy are also easier to take care of. They also have the ability to absorb and reflect a lot of heat, which can be very advantageous in a greenhouse.

Constructing a good concrete foundation will require a couple of weekends. The materials, tools and construction plans are available at a hardware store or may be ordered online and delivered.

Beyond following the instructions for mixing concrete, building the frame and correctly forming the surface, the key is temperature and humidity. It is important that you carry out the job when you anticipate average to warm temperatures, reasonably low humidity and no rain.

Whichever option you decide on, make sure you plan ahead. Ensure the floor is sturdy enough to support the benches, tables, pots and people that will be inside. After you have all that installed, it is a good deal more difficult to replace the flooring.