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Preparation and laying of epoxy resin floor toppings
Mixing
The
resin, hardener and filler (usually silica sand) are supplied to the
site in preweighed packs which will ensure that they are mixed in
the correct proportions.
Work
life
The
work life of an Epoxy resin flooring compound can be prolonged by
spreading it rapidly. This increases its surface area, dissipates
the heat produced by reaction between resin and hardener, and delays
gelation. Rapid spreading is particularly important in the summer
months.
Subfloor
levelness
The
pretreated subfloor on which an Epoxy resin based topping is to be
laid should be as level as the finished floor is required to be. The
permissible levelness tolerance for a 5-mm topping is about - 1 mm.
(a)
Self-levelling toppings
Self-levelling
toppings have a maximum binder-to-filler ratio of 1:3 and are normally
laid to a thickness of 2-3 mm.
Since
they contain a very high proportion of binder, pretreatment of the
substrate with an adhesive epoxy based primer is not normally necessary.
Toppings
with a very low filler loading are first put down in strips, then
spread evenly over the subfloor using a toothed trowel. Marks left
by the trowel are eliminated by treating the freshly laid topping
with a spiked plastic roller.
Toppings
with a low filler content cure to form smooth, dense surfaces of uniform
appearance. Few, if any, joints are needed since large areas can be
covered in a single operation.
Toppings
required to have antiskid properties are dusted with silica sand,
silicon carbide or similar material before they have set.
(b)
Mortar screeds
Epoxy
mortar screeds with a binder-to-filler ratio of 1:5 to 1:7 are recommended
for topping floors that will be subjected to severe mechanical wear
and chemical attack. Since these screeds have pronounced antiskid
properties they are especially suitable for factories where the floors
are constantly wet.
Mortar
screeds are generally laid in layers at least 3 to 5 mm thick after
the subfloor has been primed with an unfilled resin/hardener mix.
This primer can be sprayed on - to save time - or brushed on - to
ensure that it penetrates more deeply into the substrate. The mortar
screed must be laid immediately after the subfloor has been primed,
and the laying of each strip of mortar is completed before the primer
gels.
Mortar
screeds are usually laid in strips, battens being placed alongside
to provide an accurate check on section thickness and evenness. As
soon as screed has been laid on both sides of a batten it is removed
and the gap left is filled with mortar.
(c)
Floor Coatings
This
are normally applied in 3 coats at an average 500 ci(Microns) DFT,
thickness. Floor Coatings are normally used for light traffic areas
only & they are economical.
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