The FORMBLOCK system will produce load bearing walls, with
foundations of strip footing or slab floor generally specified for double brick construction. Seek expert
advice for specifics for your application.
DESIGN Although blocks
are based units of 300 millimetres (one foot), walls of any length can be
produced. Along with any door or window configurations. It is also possible
(for experienced users) to produce corners with non-square angles.
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( click to enlarge)
JOINTS are usually required to be placed in long walls made of earth
(generally every 4 metres, or under windows). The amount of
expansion and contraction of walls is related to both the earth used, and
the design of the structure and is a normal property of earth construction.
If unsure seek expert advice.
regards to the FORMBLOCK method, which will be the same as for earth
building in general, can vary from district to district. In most cases,
councils in Australia may require sample blocks to be tested by industry
authorities such as the C.S.I.R.O. and an engineer to certify the design of
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FORMBLOCK blocks made from the stabilized earth of 9:1have had no problem being
certified by these authorities.
A history of earth building in your area can give you an indication of the
chances of you project being approved.
can be used
for use in FORMBLOCK’s method of earth-wall construction is quite sandy
containing a low ratio of clay. (In fact, you can actually use 100% friable
sand.) Soils with high levels of clay can be corrected by mixing in sharp
all its forms can be used in FORMBLOCK’s method of wall construction with
or without aggregates, and with cement content of no less than 12%.
- An evenly graded ‘sandy loam’ preferably
with no more than about 10% clay. Also decomposed granite soils.
- It should be free of any organic matter
(such as humus, or top soil.)
- Aggregate no larger than about 70 mm (large
stones can cause cracking.)
- Water should be potable (drinkable and free
- Cement ,5% to 10% general purpose cement is
usual, however on site testing is advisable.
- There are 3 main tests; shrinkage,
compression and accelerated erosion tests. The latter 2 should be carried
out by a recognised authority, however it is desirable to do shrinkage
tests of you own when selecting suitable earth. For this refer to‘ The ‘Earth
Shrinkage Test Guide’. Seek expert advice if you remain uncertain about
the suitability of the earth you wish to use .
- A good guide to suitable material can be
found in the C.S.I.R.O.'s "Earth-wall
Construction" Building Technology File 06
be used for the following building situations;
- All sub floor walls sections
- To bring walls to an even level before
continuing the walls further in earth. (an
earth wall constructed on a sloping footing for example, can settle unevenly
resulting in problematic cracking.)
- For retaining walls, whether in a
building wall or landscaping.
- All lintels, consult your engineer
for your lintel specifications as they can be wide and varied.
- Further general information regard cement
EARTH can be used
in the following building situations;
- The use of cement stabilized
earth is generally acceptable for constructing load bearing walls once
the concrete sub floor wall are complete, (
the stabilized nature of the earth used in Formblocks method will certainly
cope with incidental exposure to falling rain, however constant exposure to
dampness, from pavement splash, or poor roof drainage may cause problems in
the long term.)
- Avoid slim earth columns or pillars,
FORMBLOCK recommends columns of 900 mm x 300mm wide, but once again seek
expert advice for the suitability of the columns application.
How much wall
can be done in one day?
*Based on persons of AVERAGE fitness, and assisted with a powered cement mixer.
- ONE PERSON
could comfortably accomplish a course of blocks between 6 to 12 metres (40 feet) long.
- TWO OR THREE PEOPLE could
accomplish a course of blocks around the perimeter of an average 3 bedroom
- THE NEXT COURSE of
blocks can be produced the following day, a 2.4 metre (8 feet ) high wall
would take 8 days.)
formwork is easy with just a quick scrape, or wire brushing.
© Copyright FORMBLOCK Australia Pty Ltd 2001 A.B.N. 85 072 393