Hi everyone. I am trying to work through plans of a 12x16 ft
greenhouse. It will have a concrete foundation pored, but here is the
tricky bit. I need a 10x4x3 sump chamber below the foundation. I
live near houston and we have a very high water table. The concrete
sump must be water tight (will contain fish). The foundation will be
poored 1 foot below grade. That puts the bottom of the sump 4 feet
below grade. Don't ask why or suggest alternatives, I really just
need help making this design work.
My thoughts are to dig the sump, poor the 10x4 foundation. Build
forms for the sump walls and pore them all in one go.
When pooring the actual greenhouse floo,r poor on top of the sump such
that there will be a 10x4 hole in the floor looking down into a 3 foot
Block walls will be built up from there and water proofed. When done,
it should resumble a pond in a greenhouse.
The floor when complete will contain (if I did my math right) up to 13
tons of gravel and water.
My concerns are the stress between sump and floor and potention for
How thick do I need to make my lower and upper foundations.
How thick do I need to make the walls of the sump.
My gueses are with enough rebar 8 inch foundations and 6 inch walls.
I just really do not want the sump to "break off".
I also assume if I do this myself it will take quite a bit of time and
I'll have to be concerned about it floating up out of the gound like
an empty pool. The only thing I can think of is to leave an open
drain and let it flood if needed. Once the sump is rendered and water
proof, it can be permantly flooded.
Thanks for any help!
And for those that cannot help but ask, this is part of a larger