I have a rather complex situation that certainly can benefit from
the collective wisdom and experience of this reflector.
My property has a very high water table and as a result my builder and I
decided to build the tower foundation mostly above ground. Specifically, we dug
a hole, filled it with compacted gravel that is above the water table, covered
the gravel with very thick sheets of plastic, and inserted 2' styrofoam boards
around the base. Then we poured the concrete. As a result, only about 1.5' of
the foundation is below ground, 3.5' are above. The overall dimensions are 10'
x 10' x 5'.
Now I wonder what are the additional engineering issues we need to address to
make sure the foundation will last and the 90' AN Wireless tower will stay up.
Currently, we have identified the following next steps:
1) Waterproof the concrete using silica based solutions, such as Penetron,
Xypex, etc. as permanent solution against water getting into the foundation2)
Add extra waterproofing using tar/asphalt-like solutions to make sure we have
extra protection should cracks emerge3) Add styrofoam boards to prevent against
freezing (it gets as cold as -25F in Ontario)4) Backfill around the structure
to create a mound that takes the rain and melting snow water away from the
concrete. I have also proposed we layer more plastic sheets about a foot below
the mound surface to make sure no water gets near the foundation
Any further comments and suggestions will be greatly appreciated.
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