The first step to a successful greenhouse
Your door should be at the south end, and the back wall at north if possible.
This is the most efficient use of the sun and the insulation for the north wall.
There is no substitute for good site preparation.
Site should be level, at least 12 feet from any building, tree etc,
and get a minimum of 6 hours of direct sunlight per day.
You will also need access to water and electric.
Level Ground - The area selected should be well drained and free of vegetation, large surface stones, and debris.
The steel ground posts will be driven 2 feet into the ground, so know all underground utilities and obstructions.
Call 1-800-DIG-SAFE if there are any questions at all.
Ground Cloth - A good weed barrier/landscape cloth or plastic should be used.
This should keep the weeds out of your greenhouse.
Gravel can be used on top to finish leveling the site and for a floor or base.
If you are going to grow conventionally (dirt) the ground cloth and gravel are not needed.
Gravel - Check with your local supplier for "concrete aggregate" or CA.
The price is usually around $9/yard + delivery.
3/4" to 1.25" gravel is great for fill, floor, and grow beds. Make sure the gravel or "CA" is clean.
(If doing Aquaponics you will need 3 yards for the 24'GH or 5 yards for the 36'GH for the grow beds)
It is most economical to order all the gravel you need at one time. (one delivery charge)
Water - Access to water can be a garden hose, pond pump, or as elaborate as an underground supply line.
Electric - Can be as simple as an extension cord or a complete electrical service installed by an electrician.
If you are doing a concrete floor, please follow these instructions.
Concrete Slab - 17 feet 10 inches in width and at least 1 foot longer than your greenhouse.
Consider 4-5 feet longer for a nice entry area (south end where the entry area is).
3 inch thickness is more than plenty. No footings needed.
Anchor bolts on the north and south (short) ends to attach end walls would be great but not necessary.
Anchor bolt spacing - start 6" from north end and 8" from long side.
Place every 24". South end bolts start exactly 24' or 36' from north end bolts.
The width of 17'10" allows for the ground posts to still be driven 2' into the ground. This is for the ultimate in strength against wind sheer.
If concrete is poured after the ground posts are placed, the frame should be constructed first; as there will be no room for adjustment if the concrete is poured around the posts.