I have purchased a new 10x12 Harbor Frieght greenhouse. I have watched many videos about basic structure repair to beef it up. I have figured out what I will do when spring comes. I am looking for any tips on the frame and base to make it secure. Any heating tips and etc. is appreciated.

Anna, I'm not sure what your intentions are for the "ground heat sink". In other words, I don't know whether you want it to keep the greenhouse from getting too hot in the summer or to keep the greenhouse from getting too cold in the winter. Normally a heat sink is used to keep something from getting too hot. For example, heat sinks are mounted on computer CPUs to keep them from getting too hot. They are intended to carry heat away as quickly as possible. Their analogy in an electrical circuit would be a ground wire, which "shorts" the circuit to the ground voltage through as little resistance as possible. I am in the process of excavating a foundation for a kit lean-to greenhouse that we ordered. Here in Maine the problem is to keep the greenhouse warm enough during the winter without spending a lot of money for fuel or electricity. During the summer we may not even use the greenhouse at all. So, during the winter I definitely don't want my heat to "sink" into the cold ground underneath the greenhouse. Instead of a heat sink, I am going to use a thermal mass of a rather limited amount of sand, gravel, and concrete pavers. That thermal mass will be insulated from the soil underneath by insulating foam, as much as I can afford. The thermal mass could be likened to an electrical capacitor, that stores current when the voltage is higher and releases current when the voltage starts to drop. That's what I want my thermal mass to do, namely warm up significantly during the day and release heat back into the greenhouse during the night as it cools off. Too much thermal mass won't warm up enough during the day. (A really large electrical capacitor can act rather like a short to ground.) Too little thermal mass will cool off too quickly during the night. There is a "happy medium" thermal mass that I am striving for. I intend to use enough insulation to prevent the floor from acting as a heat sink. I'm excavating deep enough to lay down several inches of insulation, and several inches of thermal mass over that. I certainly don't want to try to heat up the planet through the floor of our greenhouse. MM

I laid a used common brick floor on a concrete footing but only brough in a single water line and the drain line through the concrete. The drain (obviously) has to be embedded in the ocncrete but not the other services. I used 3" drain pipe (rather than small, more common 1 1/2" so that I could more easily flush out debris...I stepped it down to the small size for the small sink in the corner. For your size gh I'd do what I did for electrical (or phone or whatever), use good quality liquid-tight conduit and run the electircal outside and into the gh where you really need it. Easier to change the conduit locations that way than buried in the floor.

This question was on my license test. You might just luck out, just ask your building dept.... Greenhouses: A building permit or notice to the building official is not required for the construction of greenhouses covered exclusively with plastic film (in accordance with St. 1983, c. 671. This exemption does not apply if the greenhouse is to be used for large assemblies of people or uses other than normally expected for this purpose).