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Fire protection
products
Conductive
coatings
Absestos
remediation
Industrial floorings
Acryl-silicone
paints
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Though based on the
results of long term tests
and experience the present
information is given as a
guide only as utilization and
operating conditions are
extremely variable.
We cannot accept any
liability for use of the product
that must be verified by the
user.
Accurate preliminary testing
is highly advisable to obtain
the full advantage of this
product. Call in our technical
department for any further
information you may need.
An asbestos fibre
by SEM electron
microscope 1000X
Flexipol G 121 surface
by SEM electron
microscope 50X
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FLEXIPOL SYSTEM
Flexipol Primer - Flexipol G121
Asbestos-concrete remediation : encapsulation with polymeric coatings |
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ROOF COATING AND ASBESTOS ENCAPSULATION
Flat or corrugated asbestos-concrete roofing tiles have had a wide use in
building construction due to their good mechanical resistance, strong
weathering resistance and low cost.
Particularly they have been widely used
on housing blocks, industrial and
agricultural estate. Estimates done in
Italy show several millions of square
meters still covered nowadays with
asbestos concrete sheets.
Other sources estimate that as much as 90% of
large constructions built
in the last decades has been covered with these
products.
Following studies and dramatic experience of case histories have
demonstrated the severe hazard of asbestos fibres to human health and
caused the ban of this material and also the starting of actions to
progressively remediate buildings and artifacts already in service.
Although asbestos-concrete sheets have a considerable durability,
exposure to weathering and acid rain, sunlight, wind and freeze-thaw
cause
an erosion of the surface the allows asbestos fibres to be removed
from
concrete matrix and released in the environment. This process starts
as soon as the material is exposed outdoors, however the time needed to
get to a significant degree of damage and release can widely vary as a
function of exposure conditions.
After several years asbestos-concrete sheets are partly consumed and
significant emission of fibres starts. After many years the matrix is
definitely degraded, cohesion and resistance is lost, fibre release is
relevant, the material must be removed and disposed of in special
landfills, surrounding area must be decontaminated.
Several laws in many countries mandate the control of artifact containing
asbestos and give norms concerning maintenance or remediation or
removal operations.
This also applies to encapsulation with polymeric
coatings.
Those in force in Italy are the following:
Decreto Legislativo n. 277, 15 agosto 1991
Legge 27 marzo 1992, n. 257: Norme relative
alla cessazione
dell'impiego
dell'amianto
Decreto Ministeriale 6 settembre 1994
Decreto Ministeriale 14 maggio 1996
Standards UNI 10686:1998 and UNI 10687:1998 describing features
requested to asbestos encapsulating coatings for roofing, methods to
assess performance, acceptance criteria and field methods to verify
adhesion.
Decreto Ministero della Sanità 20 agosto 1999 describing operating
methods for remediation and encapsulation and enforcing UNI 10686
and classification.
The development work of IRIS Vernici for a safe and reliable
encapsulating system started just from these guidelines.
The research has been aimed at obtaining a product suitable for
application on surfaces that are not perfectly prepared
(“surface tolerant”).
This feature is extremely important to reduce
pretreatment operations
to a minimum.
The stage of surface
preparation,
in fact, raise major risks of
environment pollution, is
difficult to manage,
needs special equipments
and has a high cost
for treatment and disposal
of the removed material.
The FLEXIPOL system has been tested with several experimental
tests to assess performance by simulating the worst exposure
conditions
the product may face in the environment.
Further to
passing the standard
approval testing FLEXIPOL has been field
tested for more than five years.
Tests have been performed by
authoritative independent institutions, like
the University of Venice.
In conclusion, as it is obvious that:
- the problem cannot be ignored any further
- the presence of asbestos-concrete on roofs is a hazard
- owners and managers can be called to heavy penalties
- delay the action is anyway originating costs (monitoring, etc.)
- final removal is generally a very expensive solution
the remediation by encapsulation can often show up as a safe
and cost
effective alternative.
It is absolutely necessary to use products that are tested and
certified,
that offer the best features for safety of use, duration
ed effectiveness
in asbestos fibers blocking.
IRIS Vernici offers a system of easy application, including high
quality
materials with demonstrated performance in tests done by
officially
qualified laboratories.
SISTEMA FLEXIPOL: ENCAPSULATING COATING FOR
ASBESTOS-CONCRETE ROOFING
Flexipol Primer
Flexipol G121
| Update |
date 12.06.2000 |
Version 3.0 |
Physico-chemical characteristics of the materials are reported in
specific datasheets.
Features of the system for purpose of asbestos-concrete
encapsulation are certified by the following test reports:
Università di Venezia 05.09.1996
Università di Venezia 22.09.1999
Università di Venezia 18.05.2000 |
The system proposed by IRIS Vernici for asbestos concrete roofing
encapsulation is:
FLEXIPOL PRIMER -
A primer resistant to concrete alkalinity and
able
to penetrate in depth into the concrete matrix to consolidate,
link fibres
to
sustrate and be the perfect undercoat for the following
coats.
FLEXIPOL G 121 -
A polymer coating, waterborne based on
special
acrylic resins that harden on the surface to ensure the best
resistance to
weathering while staying flexible underneath to ensure
adhesion and
cohesion.
The system is suitable for coating non-horizontal roofs covered with
asbestos concrete or many other materials. When applied on
asbestos-concrete it ensures blocking of the asbestos fibres avoiding
dispersion into the environment and therefore reducing hazard for
health.
To get proper durability the roof must should have a
minimum inclination
of 5 % to avoid water hold-up.
The whole system
is formulated with
waterborne, low VOC, non flammable
materials with
low environmental and
safety impact.
APPLICAZION GUIDELINES:
Carefully follow the application methods, the technical datasheet
recommendations, law prescriptions and local regulations for handling
of
asbestos containing materials and good working practice.
A) Substrate preparation:
· Substrate must be free from oils and grease
· The product is designed to be applied on the substrate with the
minimum preparation possible to avoid operations that may cause
asbestos fibres release.
However relevant amounts of sediments,
moss or lychene growth or other
coarse impurities should be carefully
removed with a spatula.
· In case of very strong microorganisms growth, a liquid biocide can
be
applied prior to coating. B) Coating application:
· Before application stir carefully the product. For the primer dilute in
the
recommended ratio with clear tap water.
Check storage conditions
and,
particularly, avoid exposure to direct
sunlight or freezing.
Keep containers closed when not in use. Wear proper protective
clothes
following the materials safety datasheets.
· On dry substrate apply one coat of FLEXIPOL PRIMER by spraying
to
avoid fibres removal.
Primer must be properly diluted (primer to
water
ratio 1:4 by weight) to
ensure proper penetration in the
substrate.
Approximate usage 200 to 400 g/m 2 of diluted product
depending on
absorption.
· After 24 hours apply the first coat of FLEXIPOL G121 diluted 10%
with
water. Approximate usage 200-250 g/m 2 .
· After 24 hours apply another coat of FLEXIPOL G121, or more if
needed,
undiluted until reaching the final dry film thickness of
400-600 µm.
Approximate usage 250 g/m 2 per coat.
C) Substrate repair:
In the presence of cracks or small breakage in the substrate use a
plastic matt or non-woven tissue (sheets or tape depending on size
and
shape) with 1-2 mm mesh. When applying the first coat put the
net in
place and soak it into, or alternatively do the same after applying
locally
thicker spots of coating by spatula before the first coat.
In the latter case don't exceed 1-2 mm wet thickness. Repeat as
many
times as necessary to close the surface perfectly.
In case of
larger damaged area use a coarser mesh net before (with
function of
reinforcement) and a thinner as finishing.
It is absolutely to avoid application at temperatures lower than 10°C.
The standard UNI 10686 recommends the application of coats with
different colours to allow control of encapsulation ability during time, by
observing the depletion of the last coat when the fomer comes visible.
Thickness of the last coat must not be higher than the former.
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