Page 3 - 2017-12-CFR Volume 111 - How Many Types of Moisture Tests - December 2017

What about Accuracy?

When industry experts compared CaCl tests to in
situ RH tests, they found compelling evidence that in
situ RH data is far more useful and accurate than the
CaCl data. The CaCl test measures only surface
moisture. If the concrete surface dries out, this test
will lead you to believe the entire slab is dry. Invaria-
bly, that is not the case.

Furthermore, air temperature and RH conditions in
the room can greatly skew CaCl test results.

The in situ RH test, however, measures moisture
deep within the slab and is not affected much by am-
bient room conditions – thus providing a truer picture
of the slab’s moisture condition.

Howard Kanare, a leading expert in moisture issues
in concrete, reviewed CaCl data from many sources
and concluded that the test is fundamentally not very
accurate.

“This test gives you both false positive and false neg-
ative results. It is a test that changes, depending on
how the moisture picture within the slab changes.
Any test that gives different results depending on the
weather, the temperature, and the particular day you
do the test, is not going to give you very useful infor-
mation,” he declares.

Kanare says there’s only one test method that’s nec-
essary because it reveals the true moisture condition
within the concrete – and that is the in situ RH test.
“When we put in situ probes into the concrete slab,
we see the true moisture condition. It is the best pre-
dictor of the long-term performance of the floor,” he
says.

It couldn’t be any clearer. There’s absolutely no need
to perform multiple types of moisture tests to cover
your bases. Simply use the one test that’s proven for
accuracy – the in situ RH test. You can be confident
you’re getting the exact moisture information you
need, plus you’ll save time and money too.

3 Commercial Flooring Report December 2017