CONSTRUCTION
The secret lies in our patented cavity wall system by
which an acrylic resin cured fibreglass mesh is attached
to each face of the frame. When plastered the timber
performs merely a structural role, with a lime/cement
plaster on each face providing the insulation and finish.
The system was developed in 1993 and has been fully tested
and approved by government, local authorities and the
banks.
Temperature insulation is as good as, if not better than
that of a cavity wall of clay bricks. The SABS strength
and water resistance tests were passed easily, and there
is a 60 minute SABS fire rating.
Houses erected during the test phase 1994/5 are still
happily occupied by the original owners, and an office
building for Portnet at Cape Town Harbour subsequently
sustained the demolition of a corner of the building by a
heavy vehicle, without damage to anywhere other than that
directly impacted.
FOUNDATIONS
Mass concrete strip footings 200mm deep by 350mm wide in a
foundation trench 450mm deep support a rising wall of
190mm concrete blocks over a brick grip damp course.
Galvanised hoop iron is embedded at 800mm centres to secure a
SAP 76mm x 38mm Foundation Plate.
Click on image to enlarge
PRE -FABRICATED CAVITY
WALL PANELS
The walls comprise pre-fabricated timber wall panels of a
standard 2500mm high by 1000mm wide, erected on and nailed
to the timber foundation plate plus a ring beam wall plate
at eaves level. Acrylic resin impregnated fibreglass woven
sheeting (Duramesh) is stretched over and stapled to both
inside and outside faces, with a sheet of bituminous paper
beneath the outer face as an added precaution against
damp.
Water pipes, electrical conduit, plug and switch boxes are
installed within the panels at this stage, as well as door
frames and clisco window frames of whatever size the house
design requires.
The foundation takes one day to set. A house of 40sqm
will be erected in one further day, and will be roofed on
the third.
When erected and roofed, both wall faces are covered with
a lime/cement stucco, starting with a stipple coat applied
by a slush machine (or more properly a Tyrolean plaster
machine) which is hand held. Thereafter two plaster layers
are applied up to a total of between 20mm and
30mm. A typical mix is one bag of lime, one bag of cement
plus three wheelbarrows of sand.
The result is a nominal 76mm cavity between the two stucco
plaster walls which are structurally robust, waterproof
and have a 60 minute fire rating. Thermal efficiency
exceeds that of a clay brick cavity wall and results in
the most energy efficient product available.
| UPLOADING SHORTLY |
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Panel A
Plain Section
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Panel B
Door Section
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ROOF & INSULATION
The roof covering can be of any chosen material. A
most effective and inexpensive insulation which can also
serve as an alternative ceiling is Alucushion
FLOOR
In-situ concrete floor slab of between 75mm and 100mm is
thrown over a damp proof membrane after the walls are
plastered, and before painting and glazing. The
floor level is the same as the top of the lowest
horizontal member of the wall panels, and should be about
150mm above ground.
HOUSE PLANS
The system is suitable to adapt a wide variety of designs.
Our most popular products are typically 52sq-m 2 bedroom,
67sq-m 3 bedroom and one bathroom, or 80sq-m 3 bedroom, 2
bathroom with dining extension. There is no limitation to
size.
Sample plans:
