A word of warning and a question.

I was given a greenhouse this year. I duly laid a rectangle of concrete
(just the outline, not a complete slab) and built the greenhouse on top.
The greenhouse itself has a rolled steel base and the aluminium frame is
clipped to this steel base. Note that the steel based is NOT fixed to the
concrete - it just rests on it.

OK, you've guessed it; the entire greenhouse slipped 6 inches sideways this
weekend in the gales. Remarkably, no broken glass. That's the warning for
those planning to build a greenhouse - "bolt" it down.

Now the question - how? My concrete is about 4inches x 4inches on a
hardcore base (sunken into the ground) so won't take rawlbolts. I'm
considering a piece of dexion hammered into the ground in each internal
corner and then bolting this to the steel base. Do the readers think I need
to concrete the dexion in as well or would 2ft long pieces sunk into the
ground be enough?

The greenhouse is about 8ft x 6ft and presents the 8ft side to the wind.

Thanks for any advice.
Paul DS.

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