Let’s now move on to the G-mat membrane. This is a
waterproofing and crack-bridging membrane specifically designed for ceramic or
stone coverings to be laid on any surface. G-mat combines the features and fields of application
described above for the LITOTEX membrane with the additional features of
waterproofing, steam venting and load distribution.
These additional features are achieved thanks to the
special structure of G-mat. The membrane, in fact, consists of a bottom layer of
nonwoven fabric that is used to adhere perfectly to the cementitious adhesive,
coupled with a sheet of high density polyethylene (HDPE) in which there are
hollow cylinders covered with a fibreglass mesh whose job is to physically
imprison the adhesive used to lay the ceramics or natural stones. The HDPE sheet, in
addition to ensuring that the membrane is waterproof, also allows the venting
of any rising damp from the support, thanks to the presence of a network of
ducts communicating with each other. The cylindrical shape of the structure also brings
with it a significant increase in compressive strength as it is able to
distribute the weight, reducing the compression on a single point when affected
by a concentrated load.
In accordance with these characteristics, the fields
of application of G-mat are enlarged and may include:
waterproofing flat outdoor structures such as
balconies and terraces.
constructing barriers against rising damp present in
flooring laid on the ground floor or in basements, preventing the appearance of
efflorescence on the cement grout.
of separation between supports subject to significant deformation under load or
dimensionally unstable such as planks of wood, and ceramic coverings
The application of the G-mat membrane is not very different from that of
LITOTEX. In practice, it is
necessary to cut the rolls in advance to the desired size, then they must be
glued onto the support, using a class C2 cementitious adhesive, preferably
deformable in class S1 or highly deformable in class S2 in accordance with EN
12002, applied with a 6 mm notched trowel. Choosing the most suitable product depends on the type
of support, the size and the type of ceramic covering or stone you choose, and
the operating conditions.
For example, adhesives such as SUPERFLEX K77 or CEMENTKOL K21 mixed with
LATEXKOL are preferred. If it is
necessary to walk on the covering in a short time, fast-setting adhesives such
as LITOSTONE K99 or LITOFAST K86 may be
used, mixed with LATEXKOL if necessary. After the adhesive has finished setting, it is
possible to lay the ceramic material or stone on the G-mat, making sure to
completely fill the empty hollow with the smooth side of the trowel, “wet on
wet”, apply the adhesive with the toothed part of the trowel. Where G-mat is used
for waterproofing balconies or terraces, or as a barrier against rising damp,
the sheets must be sealed together using the LITOBAND MAXY sealing strip, as
must all angles between the floor and the wall.
Complete instructions for using LITOTEX and G-mat membranes are provided
on the technical data sheets available on www.litokol.it in the “special
products” section. In addition, our technical support department is always available to
provide the best advice for using the products and for choosing the most
appropriate one according to the work to be carried out.