5 courses of block work completed

over view of foundation and block work unto 5 courses, existing house in the back left and block making shelter

Front elevation - doorway centre - mock up render on the wall (yellow) and columns (purple)

view from top of hill down to house and down valley to Nymata - stunning view

Wall construction - corner masonry column over lapped and interlocked carefully to ensure strong bond between blocks - support lateral loading on wall

protruding interlock knocked off to make flat end of block aligning with perpendicular block

dried render mix - colour is lighter and has handmade finished quality

block making shelter converted for final giving of the block machine ceremony

Myself, Philbert and Fidel sitting centre back - standing precedent and secretary of farmers cooperative

Myself, Philbert Kalisa and Fidel Mugengana - made speachs and thanked the group for the great work they have done 

gifts of thanks - they give me a Rwanda T-shirt and two traditional Rwandan baskets

More speeches translated from English to Kinyarwandan - local language

Myself left in Rwandan T-shirt and Philbert Kalisa founder of the charity REACH for Rwanda

Mock up Part Rendered walls: sawdust, cement, power paint, sand and water

Using a rough course sand in the render to patch holes and gaps in brickwork to make a flat surface for render, and reducing any potential holes for insects and vermin to live in or move through

ditto: patching holes and small gaps to make a flatter surface for applying render

Render mixture: sawdust and cement  acting as binders. Then power paint which is cheap to make a deep rich colour to render, so colour last longer. Then using sand as aggregate and water agent for mixing and drying
Ratio by dry volume: 10 part sand : 1 part cement : 1 part sawdust
water added to make desired render consistencey (approximately 2 litre per wheelbarrow)
paint powder was 0.25 kgs per wheel barrow. 

we made half wheelbarrow mixture and applied a generous 1cm thick layer to the blockwork

taking care not to cover one's self in render as you flick the render at the wall, in Rwanda these like to use this machine to through render at the wall with and hand winding handle.

We agreed with the owner that the masonry columns should be a different colour to the walls, given that it is a distinguishing feature of his house from the context, the exterior walls yellow, the masonry columns red and inside walls white.

we plan is to render upto the window edge, therefore protecting the lower walls from erosion form heavy rains 

final touches we made to render with just water on the palette knife to give the render a smooth finish

Architectural Modelling Kids Workshop, Peace International School, Kigali, Rwanda

Up go the walls - Interlocking soil stabilised blocks - made by hand pressed block machine

damp proof course laid over cement blinder which tops and levels foundation - a rough binder is laid over sheet - mixture of  4 wheel barrow of small sand : 2 wheel barrows of big sand : 5 buckets of saw dust : 5 buckets of cement
- replacing half the usual cement with saw dust

over 1000 blocks made - first three batches are dried and cured and ready for construction
testing various mixes with clay, limestone, cement, dark orange earth and saw dust

stone foundation topped with a wrought cement blinder create uniform level - for ISSB wall to be built on - masonry column reinforce corners

plastic damp proof membrane laid beneath course on top of wrought cement blinder, which tops and levels stone foundation - cement mortar binds first four courses of blocks into place - course above 5 will be bound with smooth clay mortar.

old to new technology - wattle and daube construction behind ISSB on stone foundations in the for ground

short elevation south  has three masonry columns - marked out and measure diagonals to unsure squareness

rope lines pined between blocks with nails to give guides for straight block laying

masonry column interlocked into wall to give lateral stability in the wall

and suddenly the rain arrives .... work stops and the heavens open!

NEW RENDER: Sand (5 part) , saw dust (1 part) and water - local knowledge - cheap and strong render

Sand (5 part) , saw dust (1 part) and water - for wall render
cost of 100 kilo sack of saw dust 50p compared to cement 50 kilo sack for £10

local knowledge - Rwanda guy applys sample render to existing house

close up detail photo of sand sawdust and water mix applied onto local wattle and daube house - you can see the thin strands of saw dust act as binder to glue sand particles together

after a week in the rain and exposed to elements it has dried solid with no defects and feel very hard like cement
we will be using this render on all the internal walls instead of cement

Block Testing - three point bending test - drop test

set up there blocks for bridge test

step full body (75kg) weight on to bridge - this example failed - too high clay content in this block

 three point bending test - pass - good particle size- high water content in drying mixture of clay and lime

drop test - before - hold block at one meter off ground

drop test after - pass - slight cracking and crumbling of corners - but block remains in one