The reason for using expansion joint(s) is to give the concrete a
place to expand when it is trapped and when the pavement sections
get long and need relief to grow in summer heat. A sidewalk
trapped between the foundation and the driveway, between two
buildings, between the garage and the street are all examples of
places that need expansion joint, they are also placed about every
60 feet in sidewalks and paving. Expansion joints are installed
before the concrete is poured, they are not typically something to
install after the fact, and the results would likely not be
satisfactory .

Contraction joints are sawed or tooled to T/4 depth.and designed
to give the concrete a controlled place at which to crack.
Concrete will crack and should not ever exceed 12' in any one
direction without a contraction joint. Re-entrant corners require
joint relief as do substantial dimension changes.

It sounds to me that you had a fairly professional crew pour your
concrete and I don't disagree with anything they said. I do
assume you have sufficient contraction joints, I assume your
patio(s) touch grass on 2 or more sides so the concrete is not
trapped. I assume you have sufficient grade, 1/4" per foot, to
get water off the slab and away from the house.
______________________________
Keep the whole world singing . . . .
DanG (remove the sevens)




"Eileen" wrote in message
oups.com...
We just installed three patios and a set of stairs connected to
our
current patio. My husband noticed they did not install
expansion
strips. He questioned it, and this is their reply. My
question: are
they telling us truth, or trying to avoid rework?
"In reference to the concrete, we did dowel into the concrete as
requested.
However we did not provide expansion strips due to the fact the
point
of an expansion strip is to allow the concrete to remain free
standing
from the foundation. Therefore by doweling into the foundation,
this
would defeat the purpose of providing an expansion joint.
Consequently the expansion joint would only create an eye sore
to the
patio and more importantly provide a point of entry for water,
which
in our experience has created problems. Expansion joints have
allowed
water to enter beneath the concrete and in between the
foundation,
which after a season in Colorado of freezing and thawing will
inevitably cause problems. It is our policy not to use
expansion
strips due the problems we've experienced after using them.
Also, the
only concrete typically inspected in a county are areas for
structural
purposes. "