I am getting together resources to build a greenhouse. It will be wood framed and made with various windows I have been collecting. It will be approximately 16'x8', probably 8' tall on the sides, not sure of peak height yet.
What I am trying to decide on is the foundation. Kinda curious what you guys have used? We get a decent bit of wind and I don't want it to become a kite.
Kinda leaning towards concrete block because I can get it pretty cheap. And then doing either pea gravel or 2×4 end grain for the floor.
Any other ideas? Its on a slight hill, Soni have to build a level base for it.
by wookie___
6 Comments
In my conntry, concrete is the way
Grave pad site with 4×4 posts, a few inches wider than the building itself. 20×12 . Landscape fabric, crush and run then tamp down. I got a few quotes locally and was done at a very reasonable price. A proper raised pad will make sure your structure will survive the test of time. Your time and money, I would risk it since you’re on a hill. Concrete pad if you wanna pay for it.
Raised pressure treated wood foundation is the most cost effective option that’s long lasting.
Getting ready to do the same thing, but larger, 16×20’. Planning on covering this winter with cardboard to kill all the vegetation, cover with landscape fabric, grade out with mortar sand, pack down, level, outside perimeter with large concrete pavers, inside with left over bricks, all cracks filled in with paver set. Of course, power and water done before landscape fabric. Have a lawn sprinkler head that is actually in the back of the inside that I’m going to fit into a 55 gallon drum with a float valve to use for watering.
Good luck.
Cinderblocks or cement
If you get high winds you can’t just lay down lumber or concrete blocks on the top of the soil for the foundation. You need to have a foundation and/or anchors that go deep into the soil – like 2-4+ feet.
If it freezes in your area then you also need to consider the impact that will have on a concrete block foundation that is just sitting on the soil surface. It will heave up and down and crack during freezing and thawing cycles and could cause your repurposed window glass to crack as well.
In your case I’d build the greenhouse with a wood foundation and then pound 5-foot T-posts at each corner and every few feet along each wall. Pound them 4 feet deep and then bolt/screw/strap them to the wood foundation. T-posts are cheap, about $1/foot, and when they are sunk a few feet deep they aren’t going anywhere in high winds.
Figuring out the anchoring in high wind areas is much more important than deciding on gravel/wood/fabric for the flooring. Personally I’d just plant in the ground and use the saved $$$ for more plants.