If the pitch is too shallow it will not get the water off and will lead to puddling and then leaking. But a steeper pitch will require more materials which is also another economic concern.
Many thatch roofs in Zambia, particulary in the villages, have to be repaired or patched often, sometimes yearly. Due to economic issues people build only the bare minimum for coverage. The thicker the roof is the more protection and legendivity it will have.
Thach is an extremely sustainable material. It is an annual crop that is harvested once a year. The "dry" season when a majority on construction is performed.
Thatch
can be layered to make patterns. Both of these structures were found in Harare,
Zimbabwe. The examples to the left are a bulls head, while the example on the
bottom is a "cake effect" style.
All
these examples are from England, where snow loads are a possibility. If it can
work in England, it definetely can work in Africa.
Thatch
is used all over the country, as it should be. It is renewable and could be
done properly to last 20 years or more. The skills exist for this technique
and explored to its fullest- strength and beauty.
Thatch has great insulation values. Because of "heat mass" characteristics of the walls, inside spaces are cool in the day and warm at night. The thatch keeps the air temperature constant.