The traditional houses, especially of Kerala style, with Mangalore tiles on timber rafters are still common sights across the state. Though construction of brand new Kerala-style houses is rare, retaining and restoring such old houses is still in vogue. What is most disadvantageous in this endeavour is the maintenance of timber rafters of the roof which wears out as time passes. That is the reason why replacing such wooden rafters with those of metal structures has become increasingly common.
Suresh, a native of Kottayam, has been in the business of metal roof structures for the past few years now and talks about the advantages and the cost of this method.
The primary advantage of the metal rafters is definitely the greater lifespan it provides as compared to the wooden structure. Then comes the less maintenance it requires. If the structures are made of timber, they need to be replaced with new ones at regular intervals – most preferably every ten years. Even if they are replaced there are chances that any of the beams, the posts or the struts in the structure may get damaged over a period of time.
Another factor is that the wooden posts come usually shorter and hence the work of making the rafter is tedious and takes a longer duration. But with the metallic structure since the steel pipes can be obtained as per the needed measurement, the work becomes easier and is completed in lesser time.
However, in metallic roof rafters, one should keep it an open structure to ensure air circulation in the building.
The cost is incurred only in the initial investment. And the structure will require a relook only after a span of, say, 30 or 40 years. But people usually tend to compare the wooden roof structure with metal roofing in terms of the cost alone. That won't be wise speculation. A good steel roof structure may cost more but has better quality and it will be like penny-wise pound-foolish to go for cheaper roofing components for metal roofing and thereby compromise on the quality. It may have an adverse impact in the long run.
The same applies to other factors too like the paint, primer and even the labour. The bottom line is when the structure is done very perfectly, not much profit is made by either party. But the house will have a life, which will not let the owner bother about it for a long time to come.