Using Stumbelblocs is cheaper because they use MUCH LESS
CEMENT than standard blocks and DON'T REQUIRE MORTAR
BETWEEN COURSES or between blocks. No electricity, petrol or
diesel required in the manufacture, only local sand and cement.
Stumbelblocs are usually about 75% cheaper to produce than
purchasing standard blocks. Full blocks I've made in Maun,
Botswana have cost approximately P4.00 each (plus labour).
Because they interlock and are therefore just slotted into
place. No time is wasted laying down mortar for each course of
blocks and endlessly levelling blocks. Construction can be
achieved in record time: eg. a 3m x 4m room can be built to
roof height in 1 day (with 4 men)
Laying the Stumbelbloc
(note BlockGrip cement adhesive bonding blocks
Laying each block in place takes seconds because they interlock.
The only tools required for making blocks are a mould, a shovel
(for mixing) and a builder's trowel (for finishing).
Because they are 'wet moulded', not 'dry moulded, like standard
blocks. BlockGrip bonding agent is used to glue the blocks
together when building larger structures.
Much more accurate:
Each block is exactly 400mm x 200mm x 176mm, and they interlock
extremely precisely with the next block, either in line or at
Each full block has two large air-filled cavities which are
natural thermal insulators, and also allow the warm air in the
cavities to rise and exit the house.
Electical cable and plumbing is not chased into walls, but is
led through the cavities in the blocks. These cavities may also
be filled with insulating foam or polystyrene granules for
further insulation. No lintels required above doors/windows less
than 1.5m wide.
No special skill required:
People with little or no education or skill can manufacture and
lay the blocks. Only limited training is required.
Blocks are usually manufactured on-site, thus eliminating
BlockGrip is a white powder polymer which comes in 1Kg tubs. Mix
1kg BlockGrip with 1 bag cement and 1 wheelbarrow sand to form a
'sloppy' mix. Dip each block about 3cm into the mix before
laying in place on wall. This will bond the blocks together
extremely strongly (see photos in gallery). 1kg BlockGrip will
bond approximately 600 blocks.