Greenhouse foundation...30x96 foot...

[Kaduda]

I have a chance to pick up a 30' x 96' greenhouse...There are two going up for auction near me...

Also a pile of railway ties...Talking a few semi loads...Just gotta pay for the fuel to haul them away...

My thoughts are to build up a foundation using the railway ties to build sorta a 2' raised grow bed to place the greenhouse onto...This way in the summer my wife can plant flowers on the outside...And in the winter I can take advantage of the thermal mass from the ties and earth within...And I don't have to worry about snow along the sides as much...

I would make the foundation at least 4' wide and wrap around the entire greenhouse, except for an entrance at one end...I would be using rebar to tie things together with a few ties being used for cross bracing...

Guess it would kinda be like an in ground greenhouse...Except not having to dig a pit...Thoughts?

[GaryD]

Hi,

I love the idea of a pit greenhouse......if not the thought of the amount of work that it would take to realise it. When you speak about "ties".....are they what we call sleepers (the timber that they pin the rails to)?

Gary

[Kaduda]

Yes indeed...So I'll have an above ground pit green house...lol...

[Cecil]

Sounds cool Kaduda. Will the earth still be a good insulator when it freezes? I ask that because I've seen where styrofoam footings are placed in the foundations of aquatic pond greenhouses to keep the ground frost from cooling the inside.

[Kaduda]

Good question...I think that the outside portion may freeze a bit but the inside portion would stay warm...Though...Need more thought upon this...

Considering the both the wood and soil will have a large thermal mass....It will help with night time heating...Though soil is a poor insulator...

[GaryD]

Hi Kaduda,

Are you planning to put your fish tanks in the greenhouse, too?

The more water that you have, the more passive temperature control you'll have.

I'm thinking of using a rocket thermal heater in my greenhouse (still very much on the drawing board).

Gary

[Kaduda]

I'm thinking everything will be placed into the green house...

With this setup it will take a while to heat up, it will also take a while to cool off too...Something I like...Give me time in case of emergency...

[Cecil]

I'm thinking everything will be placed into the green house...

With this setup it will take a while to heat up, it will also take a while to cool off too...Something I like...Give me time in case of emergency...

Well in Manitoba in the winter you're going to need that insurance. :D The reason it's so cold in the northern plains just south of you is there is only a barbed wire fence blocking your cold air. ;) :D

I've added smiley faces but for some reason they are not showing up at I submit this.

[Popparex]

When you raise the greenhouse floor and fill it with earth, you're exposing it to the cold. I think you'd be better off digging a foundation wall and building that with the ties. That way you're using the earth around your GH to avoid exposing the floor to the cold and the ties will provide some level of insulation against the cold. My GH is at ground level and even with the -11F we've had, i don't even get frost along the walls in the soil in my unheated GH. I do have a unique GH basically a GH inside a GH (google Solaroof)

A second concern would be if those ties are old they likely are creosoted. If you ever decide to get rid of the AP and dig beds in the GH you'd have to worry about the contamination.

About the only good thing i see is that the creosoted ties, if buried, would cut down on voles invading the GH. I am having terrible infestation of the little suckers eating all my beets! I am sure they'd find their way through though.

Good luck! Hope you get a good price at auction! I paid $250 for a gh 26Ft wide by 254 feet long. *grin*

Poppa