Page 2 - 2017-04-CFR Volume 103 Gypsum Yes or No - April 2017

bound water also known as calcium sulfate dihy-

drate. This is important because dihydrate

means there are 2 molecules of chemically

bound and locked in water which makes it a fire

retardant or heat sink which is why it’s used in

multi-family. So if you do any multi-family work

the attributes of gypsum products are without The experts at LGM

comparison. Natural gypsum sources for ex- https://en.wikipedia.org/wiki/Gypsum specialize in consultation, correction
and resolution for flooring complaints,
ample that USG uses are very pure – well
claims, installation and performance
above 90% and some as high as 96%. Neither natural gypsum nor syn- issues.

thetic gypsum contain organics so they cannot support mold or mildew. No issue is too big, too small or too far
away for us to handle.
This is another factor to consider when installing floating floors over
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neutral pH making it much less alkaline than PC or CAC-based con-

crete.

Synthetic gypsum, more accurately

called FGD gypsum (flue gas de-

sulfurization) is a bi-product of the

cleaning of coal-fired power plant ex-

haust. Here’s how: Exhaust leaving the

combustion chamber of a coal-fired

power plant is first cleaned of ash. This

is done using filters. The collected ash

is called “fly ash.” The hot exhaust then

is forced through a limestone slurry.

The slurry is made up of finely ground

limestone and water. Limestone is

chemically called “calcium carbonate.” https://en.wikipedia.org/wiki/Flue-as_desulfurization

As the exhaust passes through the

limestone slurry, sulfur dioxide (which is a found in the exhaust) is then

“absorbed” into the limestone slurry. It is at this point when the lime-

stone slurry, aka calcium carbonate, converts into calcium sulfate –

gypsum! Synthetic gypsum is then calcined (cooked) just like natural

gypsum and as with natural gypsum USG can cook the gypsum in a

number of ways based upon the end use. Just like natural gypsum, syn-

thetic gypsum is free of organics which, like natural gypsum will not

support mold and mildew growth.

Gypsum strength is directly related to the
amount of water used during the rehydration
process as well as whether fillers such as sand

or gravel are used.

Page Layout By: Anita S. Drennon

2 Commercial Flooring Report April 2017