Greenhouse floor

mjmckinney · #1 01-21-2011, 07:13 AM

I am planning on constructing a greenhouse this spring. The basic structure will be a lean-too placed on the south side of a building. The greenhouse structure will be about 16'x24' or so.

The original plan was to put in a concrete floor with radiant hot water tubes installed in the concrete and heat the floor with hot water. The other option would be a gravel floor and heat the greenhouse with some type of standard hot air heater/furnace.

I really like the idea of heating the floor, concrete will act as a heat sink and there will be no dry hot air introduced from a heater furnace.

Other hobbyists tell me that a gravel floor will be a better option for maintaining humidity in the greenhouse - as opposed to concrete.

For those of you with greenhouses, what kind of floor do you have, are you happy with the choice, and what would you recommend for a new construction?

thanks,

Mike

tenman* · #2 01-21-2011, 09:55 AM

I too wanted concrete but was advised to go with gravel and am glad I did. My GH is about the size of yours, and was built four years ago. There is no reason you can't use gravel AND the below-level heating if its done correctly. A fellow local society member has a peagravel floor topped with pavers in the walkways. He has underfloor heat throughout the GH and it's marvelous on a cold winter day to walk in there and have your feet be warm for the first time in hours.

The gravel does allow for added humidity control and as well cooling in the summer when hosed down. Be sure to insulate the outside of your foundation during construction. It will make a big difference in heating costs, especially with subfloor heating.

mjmckinney · #3 01-21-2011, 10:35 AM

tenman,

thanks for that info. I often wondered if it were possible to install the pex heating tubes buried within a gravel bed. Do you have any details as to how your local friend installed his tubing in the pea gravel?

thanks,

Mike

jean2 · #4 04-17-2012, 02:12 PM

The problem is, the humidity will eat at the grout, etc. It will look great at first, then breaks down-at least thats my experience.