INTERLOCKING BLOCKS BETTER THAN NDARUGO STONES?

INTERLOCKING BLOCKS BETTER THAN NDARUGO STONES?

The only way to understand the affordability of interlocking blocks is to look at housing holistically. You have to understand the basics of traditional and universally accepted construction which is stone and mortar or brick and mortar.

To understand interlocking blocks is to appreciate the minimal use of mortar and steel. Mortar in Issb(interlocking stabilised soil block) is used to join the first course to the floor slab and in all the courses above the lintol/lenta/lindoo/ridoo etc.

One of questions I get through the inbox and personal email is: "Does Issb works and is it cheaper than the machine cut stones commonly known as ndarugo?".

So today I will try to answer this question to the best of my understanding because I have been fortunate to work with both machine cut stones and interlocking blocks.

We need to agree what affordable housing or low cost housing is before we continue. My biased definition of low cost is a foundation that is 900mm deep, a floor slab at 100mm, floor to ceiling height of 2300mm, windows at 1200mm square, a roof pitch of below 18 degrees, no plaster, no ceiling and no fittings and a room with a floor area of 10 square meters.

•       Eco brava interlocking brick making machine

Let us get back to the walls now that we have cleared that of our chests.

A 10 by10ft room will then (using the low cost description above) have a wall surface area of 24sm. Using the small blocks in the attached pictures means that we will theoretically require 792 blocks. If one block is valued at Kes 20.00 it means you will spend Kes 15,840.00 on the walls of the room excluding labour.

The advantages Interlocking blocks has over the ndarugo stones is you can avoid plastering and paint and your wall both inside and outside will resemble the first picture in this post.

However it is prudent to be clear that the cost of a block ranges from Kes 17.00 to Kes 30.00 depending of the availability of suitable affordable soils.

If you started life living in single rooms in Nairobi then you will agree with me when I say that interlocking block walls look better than Mabati, matofali and stone walls and your tenants wouldn't care. Guys pay rent of 2k to 3k in those rooms.

This post is targeted towards those with dreams of building rental houses of the single room variety.

In summary before I bore you with a long post I can honestly state that the affordability of interlocking block houses is directly related to the cost of suitable soils.