Description
Over the past
20 years, a wide range of systems have been
used to prevent rising damp. These include
both practical and obscure methods, some
which have been short lived, due to
difficulty in installation, dubious
effectiveness and in some cases, detrimental
effects to the treated building.
Pressure injection
chemical dampproof courses have been
successfully used for over 25 years and is a
nominated method on restoration projects
throughout the world.
The Westox Injection
System has consistently been used by
Restoration Bodies on many of Australias
oldest buildings, ranging from Victorian
Terraces to major conservation projects. The
advantage of this injection system includes
the level of installation which may be lower
than some other commonly used methods. This
provides protection to the skirting boards
and can avoid dampness bringing through new
plaster. Speed and cleanliness of
installation are two other factors in
arriving at an objective choice.
Approved applicators of
the Westox Chemical Dampproof Courses carry
out a careful survey of the problem and
provide a written report and quotation.
Enquire today to contact our Approved
Applicators.
As an accurate diagnosis
is critical in making an appraisal of any
dampness problem, an electronic meter is
used to assess moisture content and to
identify it's source. It is not uncommon to
see properties treated at great expense for
rising damp when the problem could be as
simple as a broken down pipe or other minor
repair.
After the installation of
the new damp course, the walls will
gradually dry out. Depending on the moisture
content and the thickness of the walls, this
could take in excess of one year. The
replacement of all damp affected plaster is
essential to prevent secondary dampness.
Salt contamination of the
old plaster is caused by the moisture
containing salts, rising up through the
capillaries of the brick work from the
ground below. These salts build up in the
plaster over a period of time and attract
airborne moisture. It is the expansion and
contraction of these salts which cause the
familiar rising damp symptoms of eroding and
blistering paints and plaster. The major
proportion of the salts are removed with the
old plaster. The new render is designed to
allow the passage of water vapour, so that
the residual moisture can dissipate from the
wall. With the use of a special formulated
cement additive called
Westox Salt Retarder,
the old plaster can be replaced soon after
the installation of the new dampproof course.
TECHNICAL DATA
Westox 50 is a low
molecular structure alkoxysiloxane solution
formulated to provide maximum penetration in
both brick and stone
| Colour |
Clear |
| Volume Solids |
6/7% |
| Components |
One |
| Package Size |
20 Litre Drums |
| Notes |
For specialised
applications, we have alternative
injection fluids available |
USAGE
The rate of fluid used
will be relative to the porosity of the
materials and the thickness of the walls. As
a general guide the fluid requirements are
in the region od 1.5 - 2 Litres per 110mm
thickness of wall per lineal meter.
APPLICATION
On the commencement of a
typical rising damp project, the applicator
removes the skirtings. Skirting may be
refitted after the installation of the
chemical dampproof course and the completion
of replastering. In some cases the skirtings
may be rotten and require replacement.
The damp affected plaster
is then removed to expose the brick stone.
After selecting the course
of brick or stone which will become the new
dampproof course, as series of 10mm holes
are drilled at an appropriate depth and
spacing.
The injection lances are
then introduced into the holes and a seal is
formed by a rubber expansion washer which
holds the lance firmly into the brick or
stone.
The selected Westox
Injection Fluid is then pumped via flexible
tubing into the brickwork and the fluid, now
under pressure is forced through the
cappilaries of the brick or stone until is
is visually evident that saturation has
taken place.
The lances are then
removed and the procedure repeated
progressing along the wall to be treated.
The injection fluid continues to penetrate
through masonry and mortar joints by
capillarity for approximately 24 hours.
After the full thickness
of the wall is injected the continuous
saturated section of masonry will become the
new dampproof course. After a short drying
period, the walls may be replastered to
complete the job.
The Westox Chemical
Dampproof Course is covered by the written
20 year guarantee which covers both
materials and workmanship but only applies
if the work is undertaken by a Westox
Approved Contractor.
REPLASTERING
After the 'drying out'
period (minimun 7 days), the walls are to be
replastered to the following specification:
MIXING WATER
40 parts fresh water to 1
part Westox Salt Retarder (eg 20 Litres of
water to 500mL Salt Retarder).
CEMENT MIX
1 Part OP Cement
3 Parts washed sharp
plastering sand.
IMPORTANT: do not add
lime, plasticiser or any other additives.
Mix to a workable
consistancy and apply at a minimum thickness
of 10mm.
After overnight drying the
wall may be set finished with a mixture of
hard wall plaster and hydrated lime. Should
a sponge finish of render be required, a
second coat of render may be applied on the
same day as the salt retarding coat. This
finish coat is to be of 6 sand, 1 cement, 1
lime.
After adequate drying,
either the original or replacement skirtings
may be fitted.
STORAGE
Store in a cool, dry place |
