Wednesday, 26 November 2014

Day Four of Block Making - Foundations - Latrine digging



looking south across sight down valley - foundation stone and clay mortar is all in - next is 2 bags of cement pointing


373 blocks made, with ratio of 36:1:1 of earth lime and cement - so far we have used just one bag of cement - cement in £10 a 50kg bag where as lime in 50p for the equivalent - acting as a pozzolana which extends the properties of of the cement and earth. - blocks should be covered and left to dry for at least two weeks




mixing ratio of 36:1:1 of earth lime and cement with some water makes for cost effective durable block



detail close up of foundation - builder often enjoy knocking the stones into squares and circles -enjoying the strength of the strong purple grain in the stone

the production line - earth is brought in a wheel barrow in top left - sieved over box through 5mm gapped mesh - mixed in tarp with cement, lime and water - after completing drop test the mixture is ready for machine - four people is idea for operating machine for maximum output.


overview of site

overview of site - local stone and clay mortar foundation create level base for block work to be built off - block making shelter close by prepare blocks

the owner of the house - shows me proudly 2 of his 12 rabbits  - he also has a cow and a goat - yes he is keeping animals to eat them not for domestic entertainment 

interior of house, where food is prepared and rabbits are kept - this is one of three rooms - others are a bedroom for husband, wife and two children  and a reception room

latrine hole being dug - 1 meter in diameter - earth also used for blocks making - contains many stones - rate agreed at £5 per meter down - i think building in the fact that the last few meters of a 10 meter latrine are a lot harder work

latrine digger waits for his turn - the alternate - pick, shovel and rake with short handles are used

earth changes as with depth - top soil is removed - then organic soil can be still prevalent at 40 or 50 cm - colour changes and become brighter and more orange with depth - near the surface there is a mixture of particle sizes - ground in overall softer and less compacted - after 50 cm earth becomes harder with a more consistent particle size - earth has a good mixture of clay, sand and gravel as well as variety types.
quarry at the top of the ridge some 50m from the house provides fantastic stone for strong foundations

government lead planned artificial forests provide a sustainable source of timbers for building
- as you can see the timbers are coppiced from the base never killing the tree


Saturday, 15 November 2014

Day one of block building and training - A house for a victim - Ntrama, Rwanda

The Makiga Block press is up and running

Interlocking soil stabilised blocks - pushed up and out the block machine

we testing various earth, lime, ash, oil and water mixes

setting up a system meaning the earth gets dug, sieved, mixed, watered, and loaded in a sequence to save time

setting the site, building a shelter next to the foundation which we have dug, so the travelling distances are kept to a minimum, the sheet on the  far wall low wall is facing the prevailing wind direction to protect blocks from worst weather

view from top of site, looking over existing house left and new build centre and block making shelter.

Wednesday, 12 November 2014

The faces - A house for a victim - A block making cooperative - Ntrama, Rwanda


Test Compressed Earth Blocks CEBs



Block mix is made up of earth from two samples. One area with a high chalk content other with rich dark clay.





1.7cm shrinkage in 57.5 cm length means 3% shrinkage. This is great because it means the earth has not got too much clay. It is advices that more than 12% shrinkage means construction and durability of wall can become a problem. Extreme Shrinkage can cause cracks and erosion of wall.





shrink box test

Blocks left in sun for three days to dry and shrink.





Earth sample 1 - agricultural friend below site.





Earth sample 2 - above site next to termite mound, tall termite mounds are a sign of good earth for building material.



Earth sample 3- agricultural field next to site, ground soft and ploughed recently.







daub on house house two kinds - one clay based and the other with a chalk mix - protecting base of west wall, where rain approaches from



drop test - compact earth into ball in hands and drop from 1.5m hight onto hard surface look at  piece sizes to determine moisture good for building 

good level of moisture - earth breaks into medium size pieces

drop test - too much moisture in earth piece remains in one



hand made rammed earth block - make timber box brick size, fill with earth with right moisture content

ram earth with timber element

ram edges and in layers u till evenly compressed

when compressed flip earth block out

finished block - now leave in sun for 3 days to dry shrink and harden

shrink test

ram building earth into shrink box test

oil  box before ramming earth into box


one the block is dry test strength - bridge test make gap bigger tip block brakes

step test - strong in compression no give

thumb can't dent block

pen nib press into block - minimal penetration

pen nib press into block - minimal penetration



Makiga - Straight Interlocking Soil Stabilised Hand Press Block Machine


the block machine


Makiga engineering services - fantastically helpful company in Kenya
(http://www.makiga-engineering.com)

Block  machine on palette

Machine in warehouse in Magerwa, Kigali

Nema Foundation - Cabo del Gado Mozambique - Interlocking soil stabilised block machine in action - have the same machine here is it in action!

mix and add earth, ram in with thick stick

clean off top so level

close lid and fold over pumping handle


compress buy pumping handle up and down 10 times and open lid

push leaver to lift block up out of mould, lift out careful and set to dry outside but not in direct sun