Purchasing a greenhouse can be a difficult and sometimes overwhelming process. The first factors you should consider are location, foundation and of course your budget. All foundations should be level and square. A square and level foundation will eliminate challenges later when installing your greenhouse. A raised foundation or knee wall is a good option if you prefer to add height to your greenhouse. Knee walls are commonly 12-48 inches high and can be made of various materials. If you would like a knee wall with your Sunglo greenhouse kit please notify us at 800-647-0606 to add a door drop kit to your order.
Concrete is a great option for a greenhouse foundation and often chosen among consumers because is it convenient. To attach your greenhouse to a concrete base we recommend attaching quality treated wood to the base of the greenhouse, commonly called a wood sill plate. 2 x 4’s will do. If you choose to use pressure treated wood make sure to install a barrier between the wood and aluminum, such as gasket material, as the treated wood can cause the aluminum to rust. Sunglo includes a barrier called a “boot” with each greenhouse kit.
Measure twice before cutting your wood to ensure proper dimensions. We suggest allowing a 1” border around the inside and outside of the entire greenhouse. Sunglo adds 2″ to each greenhouse size for the foundation measurements.
This is designed to allow a safe margin for irregularities in the wood sill plate. After the concrete has been poured and is level and square, a small drain should be placed in the center of the slab where water run off can drain into a gravel pit or piping that leads to a drainage area. Then your greenhouse can be bolted to the foundation. Water and electricity should be ran to the greenhouse site before the foundation is built.
Building a wood base is easy and inexpensive. Cedar and redwood are commonly used. Pressure treated wood is also a great option but make sure to put a barrier between the wood and aluminum, such as gasket material, as the treated wood can cause the aluminum to rust. The size of your base will depend on the size of your greenhouse again allowing a 1” border around the inside and outside of the greenhouse. After assembling the base and making sure your ground is level lay down a weed barrier. This allows the water to drain through but does not allow weeds to come up through the floor boards.
Pack the natural earth over the excess barrier. After your base is finished and the weed barrier is set underneath, you need to cover it. Start laying down your wood planks to make the floor. Now it’s time to attach the greenhouse frame to the base – Make sure it is level and square again by measuring from corner to corner. For added insulation, we suggest you caulk the bottom of the aluminum framing (caulk the wood then attach the frame – making sure there is a barrier between the aluminum and wood) where it meets the base with a waterproof sealant – If you are using pressure treated it is still a good idea to caulk between the base and wood. This will add extra protection to the greenhouse and keep cold air from entering and warm air from escaping in the colder months. If you are using pressure treated wood make sure the aluminum does not come into direct contact. Sunglo includes a plastic “boot” that attaches to the base rails with all our kits, so you don’t have to worry! As with all foundations please consider whether you will need water and electricity ran to the greenhouse site. Wood foundations are natural and beautiful looking! The only down side is you might have to replace the wood every 8-10 years.
If you are planning on purchasing a lean-to style greenhouse or even a small free-standing but only have room on your deck, that’s no problem! Before attaching the greenhouse base to pressure treated wood lay down a thick rubber, insulated mat that is the dimension of the floor of your greenhouse.
There are various mats you can purchase that have designs or just plain old black. Insulating underneath and around the base is a good idea also. To attach the greenhouse base to the deck we recommend contacting your hardware store representative and explaining the project. Decks are made of different materials and you wouldn’t want to ruin your deck in the process. Now insulation will be an issue as well. Depending on your style of deck please take this into consideration and do your research on what type of insulation, if any, you should use. Water and electricity can be easily ran to a greenhouse on a deck foundation as it is usually attached to a house or a building.
There is lots of info on the web about different foundations and step by step instructions on how to build them. I hope this gave you an idea of what you want to do with your foundation!
NOTE: If you choose to create a foundation that is NOT concrete we highly recommend giving the wood base a few days to settle. After 24 hours re-measure for square and level. In some cases the foundation will settle and become uneven affecting the assembly of the greenhouse. And you dont want that to happen because it can make installation very difficult!
Sunglo offers a greenhouse foundations guide that shows how to build a easy, affordable and effective foundation base. To request a free-standing or lean-to foundation guide call us at 800-647-0606.
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For more advice about greenhouse foundations or general questions leave a comment below or please e-mail us at firstname.lastname@example.org or call us at 1-800-647-0606.