Preserving tradition with a grass roof
Preserving tradition with a grass roof
11 Dezember 2010
published by thecitizen.co.tz
Tanzania — Ms Sharon Atwogeirwe has always admired grass thatched houses. However, she doesnt know if she will ever achieve her dream because different people that she has confided in say that its expensive putting up one. Since she has only seen such structures in bars, restaurants and lodges, she has come to believe them.
Ms Asha Williams who owns a lodge with her husband is someone that Ms Atwogeirwe needs to listen to in order for her to believe that she can have a cost-effective grass thatched house.
A grass thatched house is a lot more classy and peaceful, especially during the rain because you wont hear a drop of rain on the roof, she says.
Although Ms Williams doesnt disapprove of modern roofing systems (tiles and iron sheets), she says they have dominated the African traditional roofing – grass thatching. Steel is so tacky and tiles are the worst idea for a roof, she says.
She argues that people dont seem to realise that grass thatch is one classy thing if nicely done though it also depends on the type of grass and the way it is tied and placed. The couple havent replaced the grass on their structure because of the type of grass they used.
According to research, it should last for 25 years before replacing and with the Ugandan weather, I think it should last longer, Ms Williams explains. However, other experts differ as explained below.
Construction process
Mr Moses Nsubuga, an architect with Creation Architects, says the construction process is not any different from the other houses that may be roofed with tiles or iron sheets. All one needs are professional engineers to pull off the work very well. For the roof to stay intact for a long period, the grass layer has to be 150 metres thick.
The pitch range of the iron sheets matters, so does the one for the grass. It should range from 45 degrees and above, he explains. He adds that this helps the water to find its way off the roof. Grass is a product that is perishable; therefore, one should add another layer quarterly or every after six months.
Also, one cannot wait for a year to add another layer because every time the wind blows, it takes away some grass. Mr Nsubuga says the pitch should be done perfectly for the lines to be straight to give it that organised look. There are times when weed grows on top of the roof (thatch) and he explains that this happens when the grass was not well treated.
That shows that the grass has decomposed; therefore, the drainage needs replacement. According to Mr Nsubuga, a ceiling in a grass thatched house is unnecessary.
House wiring
Wiring the house is as important as any other activities in the construction process that should be paid attention too. According to Mr Mike Kusiima, an engineer and principal consultant with Kea Group, the design level of the house should be done by a qualified engineer. The sizing of the power cables matter.
Like any other buildings, when planning and building the grass thatched house, the professional should follow the international guidelines. Currently, we follow the British standards. We also follow the Institution of Engineering and Technology (IET) wiring regulations, he says.
He insists that if installation is not done well, then there will be a risk to electric shock and fire outbreak because the roofs are flammable.
Where to build
The grass thatched houses are often built away the city because of the congestion. Mr Nsubuga says, KCC has not gazetted it because of the fire that may break out.
He argues that if they are to be built in the city, there should be a difference of 10 metres to another building, which he thinks t is next to impossible.
The price
Ms Williams says each bunch of grass cost them USh1,500 to finish their Kyaninga Lodge (the name was derived from the Crater Lake that it overlooks) located in Fort portal. According to Mr Kakumbe, grass could cost from USh400,000 a track depending on where one is buying it from and transportation. He says when you put together the costs of transporting, harvesting, sorting, it would add up to USh4 million for a track.
There are no manufacturers but he says one can find it upcountry like in the eastern parts of the country and Ssese Islands. It can also be imported from the Southern Africa. Mr Kankumbe agrees with him and says most grass thatched houses are found up-country because the environment there is friendly. They both argue that people have not yet embraced the idea of the grass thatched houses because they are pretty expensive in both the construction process and maintenance. Mr Nsubuga says a grass thatched house may cost 60 per cent extra of what the other roofing materials would cost.
Advantages
Since the grass is natural, Mr Kankumbe, an architect with Absolute Designs says that it blends well with the environment. He adds that it also has an appealing look and that is why it is used for hotels and lodges. Also, the grass is not heavy; therefore, it can go on any building material- both weak and strong. Some leisure centres prefer grass thatched houses because they create a cool atmosphere.
Disadvantages
Mr Nsubuga says for one to start building a grass thatched house, they should have enough money. The building process, labour and materials are quite expensive.
