Greenhouse Foundation vs Greenhouse Base vs Greenhouse Floor

Greenhouse Foundation vs Greenhouse Base vs Greenhouse Floor

greenhouse foundation vs base vs flooring

Greenhouse base vs foundation vs floor

Greenhouse Foundation vs Base vs Floor

It seems that there has always been a lot of confusion about what goes at the “bottom” of your greenhouse. A lot of people use these three terms interchangeably. This is not true at all. Each of these 3 items is a different component of a greenhouse.

The greenhouse foundation and base pretty much serve the same purpose. They are used to give a good strong substructure to place the greenhouse on. They also help tie the greenhouse to the ground.

A greenhouse floor is another item all together. It is basically like the floor in your house.

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Greenhouse Foundation

A greenhouse foundation will be built much like any foundation you are building for your home, a garage, a shed, etc. This will all depend on your location.

Many of us have freeze/ thaw cycles that cause the ground to heave and could potentially cause damage to our greenhouse frame and / or covering. In order to build this properly you must go below your frost line and pour a footer or build a pier type foundation with Sonotubes.  They have complete instructions on their website ( if you are not familiar with this type of construction.

If you are not sure of the proper level you need to dig down to you can contact your building codes department, or possibly a local contractor.

This is a good practice for any glass greenhouse, but you can build up to a 8 x 12 single glass greenhouse without a foundation. You really want to be sure to build  a proper foundation if you are building a double glass greenhouse and a larger single glass greenhouse.

Also, any polycarbonate greenhouse over 12′ x 16′ should have a foundation. A foundation is also a good idea anytime you are attaching a greenhouse to your home or building although a lot of people will use a base with smaller polycarbonate kits.

Greenhouse Base

These are available with some of the kits on the market today. There are also some polycarbonate greenhouse manufacturers who recommend this method. A greenhouse base will be the same size as the perimeter of your greenhouse.

A kit may have a steel base, or you may choose to build your own treated lumber base. It does not come with a floor and it does not go below ground typically. The greenhouse is tied to the base and the base is then anchored into the ground. This helps to stabilize the greenhouse and keep it from getting blown over in heavy winds.

You can build a base like this for a small single glass greenhouse (up to 8′ x 12′) or for a polycarbonate greenhouse up to 12′ x 16′. With some of the kits it also serves a double function. Some of the kits require this for the doors to open properly.

Greenhouse Floor

The greenhouse floor is quite simply what you walk on. There are a whole lot of options for this. Some will choose to do a concrete floor. If you are going to do this you must address drainage when pouring the floor. Also, I suggest using a heavy broom finish, as wet concrete can get slippery.

A second option is to put ground cover down on a leveled dirt surface. This is a UV protected polypropylene material. You may have seen this at some commercial greenhouses. It is the black fabric with green stripes where they have their liners set up. It is a heavy durable material.

You can go one step further and put sand or gravel over top of the ground cover. You can also put pavers down the middle for a nice walkway. The possibilities are endless.

Some people will choose to actually build their raised beds in the greenhouse. If you are doing this you would just use the ground cover or concrete between the beds.

I have had one customer who built an intricate paver pattern inside the entire greenhouse. This is great because it is beautiful, and it is excellent as far as drainage is concerned.

Paver Floor Greenhouse

Paver Floor Greenhouse

In Conclusion

Hopefully this will clear up some of the confusion on the differences between a greenhouse base, foundation and floor. You have spent a lot of time, money and studying to find the perfect greenhouse, so be sure to build it properly so it will last a good long time.

Greenhouse Flooring Options

Pavers as a Greenhouse Floor

Fancy Paver Pattern for Greenhouse Floor

We put so much time into planning out our greenhouses — glazing options, size, lighting, bench/table configurations, even décor. But sometimes, we forget to consider one of the most basic elements of the greenhouse, the floor. There are many options for flooring material, ranging in cost from quite inexpensive to fairly costly, but every greenhouse floor must start with positive drainage. With all of the misting and watering that occurs daily, the last thing you want is to create a soggy, slick basis for walking and working. So start with good drainage and take that into account as you are making your flooring decisions, then check out these options to determine which one fits your budget, aesthetic and lifestyle. 


Although pouring a concrete slab is likely one of the more expensive flooring options, it creates a permanent, solid basis for your greenhouse activities. Much like a patio floor, a concrete greenhouse floor will need to have a surface drain installed to allow water to drain out. Pouring a concrete floor is not an easy DIY project as there are too many variables to cover, so this is an option best left to the pros. The investment will repay you many times over, though.


Similar to the concrete slab, stone flooring is a more permanent option, especially when mortared in place. If you opt to forego mortaring, space the stone closer together and use a stabilizer in between such as decomposed granite or gravel. Make sure you choose a stone that has a flatter, smooth surface, as you don’t want to be tripping as you work — look for larger, flatter pieces labeled “flagstone” or “patio stone,” and forego lesser expensive “field stone” that tends to have a bumpy, irregular surface.  A surface drain is also a must if you opt for a mortared stone floor.


Brick flooring is a beautiful, elegant and permanent option, but it can also be a more expensive one. Brick, like stone, does not necessarily need to be mortared in place, but it will need a surface drain if it is. If your greenhouse location has relatively level ground, and you have some basic DIY skills, this could be a project for you to take on, but most greenhouse owners will want to consider hiring the pros to correctly install this floor.


Many greenhouse owners opt for pea gravel for their flooring. It’s inexpensive, creates positive drainage and is readily available. You can also opt to install weed barrier underneath the gravel, and option that I recommend to keep the gravel from settling into the soil and disappearing. Be sure to keep the gravel clean by periodically washing it down, as a build-up of moisture can create a slick surface. As easy DIY project, gravel is a great middle-of-the-road approach to creating a functional greenhouse floor. 

Weed Cloth

Also known as weed barrier, this woven black fabric is the choice of many commercial greenhouses to suppress weeds and create a nice level floor for walking and working. It allows water to pass through, creating positive drainage, while at the same time keeping your floor from becoming muddy. If you choose this option, go for the more expensive, commercial grade fabric, as it truly is a more durable and effective product. As with most things in life, you get what you pay for — and why go to the trouble of installing this product if it’s not going to do the job?


Good old-fashioned mulch is a great option for greenhouse floors — it provides great drainage, sure footing and enriches the soil as it breaks down. It’s also readily available and inexpensive. Opt for a higher quality shredded mulch rather than wood chips, as shredded mulch interlocks to form a tighter mat upon which to walk. You’ll need to replenish your mulch floor as it breaks down, but it’s an easy annual task that any homeowner can do. It’s available both in bags as well as in bulk (per cubic yard), with the bulk option being the least expensive by far.