In this region, building materials typically fall into four groups:
The geological composition of the soil made the use of mud in the building construction possible. There are abundant dark-grey and dark brown laterite soils in Yoruba land. The quantity needed each time for the preparation of mud for the walling and fencing of their houses was dug up for use.
The vegetation in Yoruba land is basically thick rain-forest from where the people were able to obtain the necessary building materials such as forked wood, the raffia and oil palm tree leaves, large leaves, ropes, etc. The forked wood was used as the load bearing element in the building construction. The forked wood was very useful in two other areas; it dictated the rectangular form of the houses which the people learned to handle and the issue of demountability of any part or the whole of a construction posed little or no problem to the builders. With the availability of palm trees and raffia palm, the people were able to produce roofing mats with the leaves. The ribs of the raffia palm leaves and sticks that were obtained from the forest were used as rafters and purlins. On the other hand, the ropes of various kind obtained from the forest were used to tie the above named elements at their either meeting or at crossing points.
The Earth dug up and plant materials were used in three different ways in South-West Nigeria:
Block Wall system – which involves the production of bricks from this dug-up earth
Wattle and Daub – which is a composite building material used for making walls, in which a woven lattice of wooden strips called wattle is daubed with a sticky material usually made of some combination of wet soil, clay, sand, animal dung and straw.
Rammed Earth – involves compressing a damp mixture of earth that has suitable proportions of sand, gravel and clay (sometimes with an added stabilizer) into an externally supported frame or mould, creating either a solid wall of earth or individual blocks.
Dmochowski Z.R. An introduction to Nigerian Traditional Architecture
Ethnographica Ltd., London 1990, 3 vols
S.O. Izomoh Nigerian Traditional Architecture
S.M.O. Aka and Brothers Press, Benin City 1994
Unde, Robert.T Form And The Visual Dialogue In Architecture (with reflections on architectural expressiveness)
Bsc. (Arch) thesis Ahmadu Bello University, Zaria. 1986.
Curry, Tim Countries and their cultures
Kevin Butler Yoruba Architecture
Wikipedia Rammed Earth
Wattle and Daub
African Legacy – School of Conservation Sciences, Bournemouth University