Concrete patio and clay soil: preventing cracks
 

We live in Northen California north of San Francisco.
Our temperatures range from the 30's at night in the winter to the 70's and
80's in the summer with occasional periods of 90's.
Our rainfall ranges from not a drop of moisture for months to constant
daily rain for months.
Our soil is pure clay with tons of shrinkage and expansion.
And we've got earth movement from the occasional tremor (earthquake-style).

Is there such a thing as a concrete patio that won't crack and split over
time?
What's the best preparation that will minimize cracking and shifting given
the conditions described above?

Thanks

No. Concrete is capable of enormously greater compressive than tensile
stress. Reinforcing steel is used for tensile strength, which will
have to cope with potentially large stresses.

It will crack, especially thin, large-area slabs. That's why tools are
used to make "parting lines" in slab, on pouring- to locate where the
cracks will be.

Properly dimensioned, supported, and drained below, problems will be
minimized. Quality of materials and workmanship are important,
obviously.

HTH,
J

Marty wrote:
We live in Northen California north of San Francisco.
Our temperatures range from the 30's at night in the winter to the
70's and 80's in the summer with occasional periods of 90's.
Our rainfall ranges from not a drop of moisture for months to
constant daily rain for months.
Our soil is pure clay with tons of shrinkage and expansion.
And we've got earth movement from the occasional tremor
(earthquake-style).
Is there such a thing as a concrete patio that won't crack and split
over time?
What's the best preparation that will minimize cracking and shifting
given the conditions described above?

Thanks

Sure but it is expensive.

Good foundation lots of rebar and concrete. Normally the problem is
approached by directing where it will crack with intentional weak spots cut
or formed into the concrete.

--
Joseph Meehan

Dia duit

(earthquake-style).
Is there such a thing as a concrete patio that won't crack and split
over time?
What's the best preparation that will minimize cracking and shifting
given the conditions described above?

Thanks

Sure but it is expensive.

Good foundation lots of rebar and concrete. Normally the problem is
approached by directing where it will crack with intentional weak spots cut
or formed into the concrete.


Set a pair of huge concrete beams one way,
and truck in pre-stressed concrete planks
to drop over them the other way.