Golunov S.A. «Fasted termo-insulation systems — an effective and reliable way of energy saving in consrtuction»

Thermal insulation of buildings with the use of warmthkeeping
material — insulant made of mineral wool or polystyrene
foam coated with thin plaster layers (ETICS) first was
applied in Europe in 50 — 60s of the last century.

However the real boom in their development in Europe
began after East and West Germany reunion. During
5 years only, since 1991, the use of Outside Fastened Thermo-
insulation System (OFTS) has increased by three times
and nowadays balances around the mark of 40 millions of
square meters per year. In addition to that in Western and
Central Europe it is planned to implement by 2010 the next
step for reducing domestic heating costs and to fix them at
the level of 1000 l of fuel equivalent per household. With
that, energy losses through outside walls will amount to 10
kW•hr/sq. m.

In Russian Federation, in 1995–1998, some construction
norms and regulations concerning energy saving have been
also revised (for instance, Additions №3 and №4 to the Construction
Norms and Regulations (CN and R) P-3-79*). New
requirements to enclosing wall parts brought into force since
January 1st, 2000, made the necessity to apply new energy
saving materials and technologies quite evident.

So what do we get applying faсade thermo-insulation?
The energy used for heating of a building makes up to 70%
of total energy spent for its upkeeping. The use of thermoinsulation
allows decreasing heating costs at least by 50%. Besides,
the emission of contaminating substances into the atmosphere
as a result of fuel burning process can be significantly

Apart from substantially saving the heating energy,
the thermo-insulation systems make to a large measure for
increasing of dwellings quality and comfort; bring in more
healthy and cozy home climate, providing the temperature of
outside walls’ inside surface practically equal to the air temperature
inside the building; help to get rid of draughts; make
houses cooler in summer and warmer in winter.

Besides, applying effective thermo-insulation prevents
supporting constructions damage and outside walls’ defects
(such as cracks, or over moisturizing) formation. Outside walls
remain dry because the «dew point» is brought out into the insulant.
The building wall constructions are protected against
temperature fluctuations and against moisture penetrating inside a wall, which positively influences the useful life of a
building. The use of OFTS reduces load on foundation, increases
building useful space at the equal built-up area, which
certainly makes the real estate more valuable. Aside from that,
applying OFTS has also its positive influence on construction
costs, because in this case outside walls can be made thinner
and of cheaper materials.

So what are the main tasks for the fastened thermo-insulation
system? First of all there are the following ones:

• Efficiency — maximal decrease of building’s heating
(conditioning) costs at reasonable price;

• Reliability — providing the system’s physical-mechanical
characteristics needed for its projected load
bearing and impacts;

• Longevity — the system’s maximal service life without
additional substantial repair costs;

• Industriability — simple implementing, minimal intensity
of work and resources;

• Esthetics — visual attraction providing and possibilities
to create flexible architectural forms;

• Ecology — fuel resources saving, decrease pollutions
in the atmosphere.

Finding solutions for these tasks is only possible in the
case of a complex, system approach to the development and
use of materials and components for building heat insulation,
only in the case of considering outside insulation as being a
composite system in which every element has its value and
cannot be interchanged in an arbitrary way

Thus, OFTS can be defined as a complex system implemented
on a construction site, which consists of components
manufactured in industrial way by a «system» manufacturer
and contains specific materials and elements, which were
chosen by the «system» manufacturer and are intended both
for the system itself and for the foundation the system is installed

OFTS consists of specific elements which are original for
every given system. But the basic components can be pointed
out, each of which performs in the system one or another specific
function, namely:

• Glue compound (adhesive) and special mechanical
fixing elements (nailing plugs) intended for fixing
warmth-keeping material to the supporting structure;

• A «system» thermo-insulating material (mineral plate,
expanded plastic…) providing required factor of a
building thermo-insulation;

• One or two layers of basic (reinforcing) compound, including
special reinforcing elements;

• System reinforcing elements (various alkali-proof fiber
glass meshes, aluminum angled reinforcing profiles
etc.) which increase stability against outside mechanical

• Finishing coats which contain materials and elements
of decorative coating, protecting the system against
atmospheric precipitation getting inside.

The most important part of the system is the basic (reinforcing)
compound that is a layer of mixture which is being
spread on the top of thermo-insulating material. This layer is
reinforced with special mesh made of fiber glass and treated
with polymeric compounds (for making it alkali-resistant).
The base layer is the main part to determine the substantial
physical and mechanical characteristics of the system as a
whole. Being the main protective layer for the thermo-insulating material, it bears and distributes all outside and inside
loads and impacts (such as mechanical load impact, temperature
deformations, shrinkage etc.). It must provide good adhesion
to the insulant and have high elasticity and impact resistance,
low shrinkage, good vapor permeability and low water
absorption ability. Therefore the right choice of the base compound
composition and its correct applying on the construction
site is the foundation for normal operation of the system
as a whole for long years to come.

For determining qualitative and physical-mechanical
parameters, in European countries in 2003 a regulatory document
was approved, which has been worked out by ECTA
(European Committee for Technical Approvals), this is ETAG
004. It now defines the order of OFTS’s tests and certification
in the European union countries. Besides, several other regulatory
documents are in force (such as EN 13499, EN 13500),
which also present the base for technical approbation procedure
of the system and system materials.

The ETAG 004 document stipulates proceeding for the
complex trial of the system (as a complete «sandwich») on a
sample of not less than 6 sq. m size (Pic. 1) after the system’s
having passed a certain amount of thermal cycles.

There is a certain approbation system for fastened
thermo-insulation system also in Russia, it is implemented
by State Unitary Enterprise «FCS» after several procedures
including both fire-resistance and climate trials of
the system as a whole and additional tests of its separate
components. Requirements for physical-mechanical parameters (such as adhesion, for instance) are higher than
similar requirements stipulated by European norms. Also
now there are works carried out to create the Russian normative
basis (national standards). Several characteristics of
materials to be the part of the basis are listed below.

Pic. 1 Requirements to solutions for fastened thermo-insulation systems according to ETAG 004 Hydro-thermal behavior on special tools: (Special climate control unit provides conditions imitating real climatic action)

As it can be seen from the listed regulatory parameters,
the requirements to the system components are rather
high. Therefore the necessity to apply special additives, e.g.
those increasing adhesion, when developing compositions
of dry mixtures for gluing, basic and finishing compounds
in thermo-insulating systems OFTS, becomes evident.

There are re-dispersive polymer powders among
these additives, these powders not only improve the main properties of such compounds, but also give them completely
new unique merits, for example, providing adhesion
to a polymer (polystyrene) carrying base, which is
absolutely impossible to get when using a simple mineral

Table 1 Parameters for hardened base plaster layer

Correctly created compositions of mixtures used to
make OFTS allows to improve substantially such parameters
as follow:

• processing time (open time), improving the system installation
process, reducing labour costs and increasing
work efficiency

• resistance to perforation and impact resistance, increasing
stability against external mechanical impacts;

• shrinkage, reducing the possibility of cracks forming
in the system;

• water resistance, giving hydrophobic properties
for the system, preventing water penetration inside;

• elasticity, improving the system function under the
conditions of fluctuations of outside temperature and

• longevity, increasing atmosphere-resistance of the
system, OFTS service life, increasing period for repair
and renovation procedures.

In conclusion it would be appropriate to emphasize
once more that to solve the tasks to increase effectiveness
and energy saving in the modern construction is impossible
without applying modern technologies, to which fastened
thermo-insulation systems definitely belong. OFTS,
which are high effective solutions in the sphere of thermo-
insulation, consist of large amount of components and
require a complex approach.

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