Tuesday, September 26, 2006

What lies between chengal and merbau

Remember this picture? It was in The Star on Saturday. The people's leader, Samy Vellu, was on a ladder, flashlight in hand, poking his head through the ceiling finish of a classroom. He was doing a personal inspection, so the story goes.

So the story goes, the administration of SJK(C) Mah Hua in Kampung Selamat, Penang claimed that its RM100,000 bill for roof repairs was not justified. Works Minister Samy, peeved with all the allegations surrounding school repairs lately, decided to take time out from his very, very tight schedule to check the work out for himself. (I mean, he was too busy to meet Shahrir's Public Accounts Committee back during the CIQ/crooked platform compensation episode. Funny, priorities and time management.)

Said Samy: “I wanted to see the work done on this roof. I have asked the PWD to review the costs of this repair work, including the profits made by the contractor.”

“From my personal inspection, I find that some high quality cengal or merbau wood has been used,” he told reporters.

Chengal OR merbau, Samy?

Poor reporters. Taken for a ride again. There's a very good chance Showman Samy doesn't know his wood types, and was just rattling off to impress the kids.

See, chengal and merbau are two very different woods; different appearance, properties, and ultimately cost. You can tell them apart quite easily. There may be some tropical woods similar in appearance to chengal, but merbau ain't one of them.

Chengal has very tight grain, being among the densest of woods as it is, and is a dark dirty brown when aired. It's the colour of day-old coffee rings on your mug. Merbau is coarse, its grain easily visible. Merbau is orangey brown like kaya on your bread.

Structurally speaking, chengal is serious shit – under the Malaysian Timber Industry Board's strength grouping, chengal is king of the peninsular woods (rated SG1, the strongest). Plus it's tropics-ready, resistant to the rotting juices of many bugs and fungi. Which is why chengal was traditionally used in heavy outdoor construction – railroad sleepers, telephone poles, boats... you get the picture. Today, it is almost precious, mainly as an architectural timber exposed to the elements eg trellises, decks and porches. You'd better be rich to want to use chengal.

Merbau isn't as strong structurally. It's grouped under SG4 along with resak, another popular tropical wood. Merbau is pretty when milled and finished; the West and Japan use it as hardwood flooring. Rarely is it used as primary structure.

Why am I making a big deal of this?

I detest spin. Worse, I hate liers, thieves and the sorts. And lastly, nothing makes sense in the story so far.

Chengal, being a protected wood today and hence in limited supply, costs up to twice more than its nearest neighbour-in-strength balau. It probably costs up to four times more than merbau.

No architect or engineer worth his salt would specify chengal for basic roof trusses. It doesn't make economic sense. The RM100k budget would be laughable. Honestly, it's seldom even used in high-end bungalows. Similarly, I don't know of any architect/engineer who'd specify merbau for roof structure – as an SG4 timber, it's not quite there. It's deemed a pretty wood. (Roofers I know use kekatong or kempas, which are SG2 members.)

In fact, forget wood - light-gauge steel trusses would've been the way to go. They're cost-effective and happen to be the industry standard. They're termite-free, recyclable and more precise. Drive by any housing or commercial development, low-cost or high-end, and you'll see these steel frames up. Why didn't they use this ready technology?

Did JKR err in specifying an outdated product? Is this what's been happening in typical school repairs? You smell a rat? I do. The mind shudders at the possibilities from this little misadventure.

So Samy, chengal or merbau? For the more informed, that's like saying "titanium or tin". With your flashlight and your head poked into the roof cavity, could you really tell?

Or did you really not want to.


Anonymous said...

You must be a structural engineer or in the wood trade business. You definitely know your stuff. Samy Vellu perpetuates the stereotype Malaysian Indian - full of bull.

You are right that steel is cheaper than Chengal like only 1/3 the cost. As you said using Merbau does not make structural sense (its used for indoor cosmetic purposes).

This thing is the same as his '21 new Tamil school' crock. This is whaat Samy 'The Bull' actually means .

straits mongrel said...

Tks, but i'm a mere architect trained in an unrecognised university. Really enjoy structure and material, and their honest expressions... btw, while i agree emphatically with most of your thoughts, i take exception to stereotypes, Malaysian Indian or otherwise - unless of course it's a good ol' harmless joke. Those i enjoy as much as structure :)