The floor is the part of a greenhouse most people decide last and regret first. You can pick the perfect kit, orient it to the sun, and install flawless ventilation, then spend three seasons fighting standing water, slick mud, or a surface that turns to a sauna by noon. The floor controls drainage, how much daytime heat the structure holds overnight, how easy it is to keep clean, and whether you can stand comfortably in it for an afternoon of potting. It deserves a real decision, not an afterthought.
There is no single best greenhouse floor. The right answer depends on your climate, your budget, whether you grow in beds or on benches, and how permanent you want the structure to be. Below are the four options worth considering, what each does well, and where each falls short.
What a greenhouse floor actually has to do
Before comparing materials, get clear on the jobs a good floor performs. Drainage comes first: a greenhouse generates a surprising amount of water from hand watering, condensation, and spills, and that water has to go somewhere other than a puddle around your feet. A floor that drains freely also breaks the cycle of constant damp that breeds algae, fungus gnats, and root rot.
The second job is thermal. A dense floor absorbs sunlight during the day and releases that warmth at night, smoothing out the temperature swings that stress seedlings. The third is simply comfort and cleanliness: a stable, level surface you can walk, roll a cart across, and hose down without creating a swamp. Keep those three jobs in mind and the trade-offs between materials get a lot clearer.
Gravel: the practical default
For most backyard greenhouses, a gravel floor is the sensible starting point, and it is what many growers settle on after trying everything else. Crushed stone drains almost perfectly, costs little, and needs no skilled labour to install.
The method matters. Excavate 3 to 4 inches, lay a woven landscape fabric to block weeds, then spread washed pea gravel or 3/4-inch crushed stone on top. Pea gravel is rounder and gentler underfoot; crushed stone locks together better and stays put under a cart. Either way, water drains straight through, and on a hot day you can splash the gravel to raise humidity for your plants.
For a 162 sq ft footprint like the Drivhus, plan on roughly 1.5 to 2 cubic yards of stone, which runs $80 to $200 depending on your region. The downsides are honest ones: gravel is awkward for a wheelchair or wheeled stool, small stones migrate into pots, and it offers less thermal mass than solid paving. For most growers, those are easy trade-offs for the price and the bulletproof drainage.
Pavers: the best all-rounder
If you want a floor that drains well, stores heat, and still looks finished, concrete or stone pavers are the strongest all-round choice. Set on a base of compacted gravel and sand, pavers give you a firm, level surface with gaps between units that let water seep away.
The thermal payoff is the real reason to choose them. Dark pavers soak up sun all afternoon and radiate it back after dark, and in a well-sealed greenhouse that can mean several degrees of overnight protection in spring and fall. They are easy to sweep, kind to wheeled carts, and you can lift one to run an irrigation line or fix drainage years later.
The cost is the catch. Expect $4 to $8 per square foot in materials, so $650 to $1,300 for a 162 sq ft floor, plus a weekend of fairly physical work getting the base flat. A common compromise is a paver path down the centre where you walk and work, with gravel or beds on either side. You get the comfort and thermal mass where it counts without paving the whole footprint.
Deck tiles and wood: when you are building on a deck
If your greenhouse sits on an existing wood deck, you are working with a different set of rules. Interlocking deck tiles, often cedar, composite, or plastic grid, snap together over the deck surface to give you a level, draining floor that protects the boards underneath from constant moisture.
The appeal is speed and reversibility: tiles drop into place in an afternoon and lift out if you ever move the structure. They drain through the gaps and feel warmer underfoot than stone. The limitation is thermal: wood and plastic store almost no heat, so you lose the overnight buffering that gravel or pavers provide. They also need airflow underneath to avoid trapping moisture against the deck, and organic debris between tiles will eventually grow algae if you never clean it.
For deck installations, the bigger question is anchoring, not flooring. A 13.5' x 12' structure rated for 115 km/h winds has to be fastened into the deck framing properly, so plan that before you choose a tile. The Drivhus is built to be deck-mountable, and its powder-coated aluminum frame and 6mm twin-wall panels mean the only floor you are protecting is the wood, not the greenhouse itself. You can see the full kit and dimensions on the Drivhus product page.
Concrete: the permanent option
A poured concrete slab is the most durable, lowest-maintenance floor you can build, and the most committed. It gives you a perfectly flat, easy-to-clean surface, excellent thermal mass, and a foundation that will outlast the greenhouse itself. For a commercial setup or a greenhouse you never intend to move, it is hard to beat.
The drawbacks are drainage and permanence. Smooth concrete sheds water rather than absorbing it, so you have to build in a slight slope toward a drain or a gravel strip, or you will create puddles. It is the most expensive option, typically $6 to $12 per square foot poured, and it is not something you reverse on a weekend. If you choose concrete, broom-finish it for grip and add a central drain or a perimeter gravel channel so all that water has a clear exit.
Matching the floor to your climate and use
Work backward from how you will use the space. If you grow mostly in raised beds or pots on benches and want the cheapest reliable floor, gravel wins. If you want four-season performance and value overnight heat retention in a zone 4 to 6 climate, pavers give you thermal mass without sacrificing drainage. On a deck, interlocking tiles keep the install reversible. For a permanent, commercial-grade base, concrete with proper slope is the long-term answer.
Climate tips the scale too. In a wet coastal region, prioritize drainage and lean toward gravel or open-jointed pavers. In a cold prairie or northeast climate where overnight lows are the enemy, the thermal mass of dark pavers or a slab earns its keep. And in any climate, a mixed floor, a solid paved path flanked by gravel and beds, often beats committing the whole footprint to one material.
Final thoughts
Start with drainage, because no floor that holds water will ever be pleasant to work in. Then decide how much overnight heat you want the floor to give back, and how permanent you want the whole setup to be. Gravel is the low-cost workhorse, pavers are the balanced favourite, deck tiles fit a deck install, and concrete is the forever option. Whatever you choose, get the base flat and level before you start, because every floor is only as good as the ground you prepare under it. Build it right once and you will barely think about it again.