input from other greenhouse owners
 

I need some input on My greenhouse that i'm getting closer to being done. I was woundering if laying brick for the floor would have the same effect as putting down gravel ? I know most stone can be a heat sink or a cold sink but do to heating a greehouse here in nebraska you would want to keep it as warm as you can would brick work or would gravel work better?

For me it's all about what do you want to walk on and how hard do you want to work to keep it clean and then cost. I personally hate gravel or loose stone and I do understand the heat retention thing but then how much floor is really exposed to the sun for heating.... I like brick or solid stone or treated wood. I used treated wood so the water drains and it's easy to keep clean

I have about a 10" deep layer of gravel on the floor or my gh, with 2" of foundation insulation foam beneath that to limit the thermal transfer from the ground to the gravel. I think that gravel/stone/brick/etc really only serves as a heat sink if it is exposed to a heat source during the day; water is a much better heat sink... I mainly used gravel so I could water to my hearts content and not have to worry about drainage, it has the added bonus of being easy on my feet (read, I like to be barefoot in the gh...)
Just my 2 cents,
Adam

I have crushed limestone in my 30 x 36 GH and I like the choice. Any flooring is going to be cold. Try walking around a house on a slab. Even in moderate climates bare feet are not very comfortable.

I agree with earlier comment about gravel. It can remain loose forever because it's smooth and rounded. Crushed whatever (limestone for me) is irregular and rough. It packs and doesn't have the effect of walking in beach sand. Also from earlier, I like the opportunity to water without having standing water like you will on any solid surface. There is also much more surface area to the crushed rock so that it holds moisture and helps humidity in the GH.

In my opinion, I'm happy with my choice. I can't think of any downside. Rather than insulation material. I put heavy duty landscape fabric under mine to prevent mixing of the rock into the clay below. The insulation might be a very good idea if you can get something that is durable enough.

As Adam did, I put 3" of Styrofoam under the floor as well as in the sidewalls. The treated decking allows most of the water to drain and the sun burns off the rest so I get some humidity which is a problem for me and since I am a clean-freak, it is easy to keep it clean... so this has worked for me but maybe not for others.

Funny, even in the dead of winter, if the sun is shining the gravel will be warm enough to go barefoot--either that or I've got tough feet... :)

Thanks everyone for the input i think the brick will be best for me and i'll leave a 1/4 inch to a 1/2 inch grout line to fill with sand to let stuff drain. Plus the brick is going to be a recycled brick that i will be able to get as much as i want and also do some landscaping with the left over.
thanks to everytone that helped with my posting

I've got 50cm square paving slabs as the base. I had never really thought of thermal properties... more what I wanted to walk on.

Like Doc, I don't like walking on gravel... I want to walk barefeet as well (at least in the summer, not in the frozen temps outside we have now) and would really hate doing that on gravel.

The slabs drain really well, we layed them on a mixture of sand and cement and layed them very close together with no grout. I throw water on the floor all the time and it does not pool, just drains away between the slabs.

Doc does the foam help ? I had never thought of that.

After a lot of research here with Greenhouse vendors and with construction engineers (I have a bunch of them among my friends :D) the final setting for the foundation of my greenhouse was:

-Side walls up to 75 cm deep in the ground - this the minimum needed in my region to cut the frost line and reach the "semi-permanent stable" temperature below the ground. If you go deep enough (75 cm is a good average, but in some places you could need 100 cm or just 50 cm), there is no need to put an insulation layer below the greenhouse "floor", but only around it (see next point)
-Insulation panels on the outside of the walls- Same panels used for house construction. They last "forever" and are not expensive at all.
-Inside of the greenhouse I have left the ground as it is, in order to help increasing humidity and being able to water without worrying too much about drainage (the ground absorb the water pretty quick!). Due to the iunsulation on the outside the ground does not cool down in winter (now we have -10°C) or warms up in summer: it stays at around 18°C all the time.
-Next year (not done this year due to my back surgery), an approx. 10 cm thick layer of LECA will placed on top of the ground, which should help further to increase humidity. Between the benches, 50x50 cm square paving slabs will be placed, as I think it is easier to walk on paving slabs than on moving LECA/Gravel...

Pictures of the construction steps of the greenhouse foundation can be seen here: http://www.orchidboard.com/community...step-step.html