Poring Over Flowable Cement Terrazzo - International Masonry ...

Desired service rating of the floor also factors in when
choosing a primer. 3 As with the moisture and crack suppression
membranes, the primer should be sourced from the same
manufacturer to ensure compatibility with the binder.
Pouring the matrix
Flowable cement products differ from other types of
terrazzo due to the composition of their matrix, along
with the resulting viscosity and impact on the sequence of
installation steps.
Traditional systems, such as sand cushion or epoxy terrazzo,
require most of the aggregate be added to the matrix during
the initial mixing. This results in a relatively stiff mixture
that gets troweled into place between the divider strips. The
mixture hardens in 24 to 48 hours, and is subsequently
ground to the desired finish. It has a calculated volatile
organic compound (VOC) measurement of 0 g/L, since the
materials are all inert. (This means, unlike most other
terrazzo assemblies, flowable cement products are entirely
VOC-free.)
Flowable terrazzo’s binder comes bagged as a powder and is
mixed with water and poured in place before any aggregate is
On a typical terrazzo floor, trained installers trowel
on the matrix/aggregate mixture.
added. The proportions of 4.50 to 4.73 L (4.75 to 5 quarts) of
water per 22.7-kg (50-lb) bag of powder must be followed
precisely and consistently, taking care not to over-water the
mix. Typically, two bags are mixed at a time, using an
eggbeater paddle at 1100 rpm. Over-mixing could trap air,
which may shorten the product’s pot life or cause pinholing
during application (or floor-curling thereafter). When
properly mixed, this binder is the key to flowable terrazzo.
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