hi,

just would like to find out what are the roof tiles(seen all over thailand blue coloured) made out of?

i know they are not concrete,i suspect its made out of asbestos.can anyone clarifie that.thanks.

I have a feeling they are stamped out, coated metal sheets, made to look like tiles.

I have a feeling they are stamped out, coated metal sheets, made to look like tiles.

I think the OP is talking about the fibre-cement roofing sheets that are common in Thailand. Generally these are made from cement reinforced with polypropylene. This product replaced the older asbestos-cement sheets. I'm not sure how you tell the difference in Thailand if you are looking at older sheets. In the West people say that moss grows more readily on the asbestos version, which many people liked because they were relatively strong. These sheets are quite large in contrast to tiles proper, which are small, heavy and made of fired clay. Apart from fibre-cement sheets it is also possible to get sheets made from steel or GRP.

I have a feeling they are stamped out, coated metal sheets, made to look like tiles.

I think the OP is talking about the fibre-cement roofing sheets that are common in Thailand. Generally these are made from cement reinforced with polypropylene. This product replaced the older asbestos-cement sheets. I'm not sure how you tell the difference in Thailand if you are looking at older sheets. In the West people say that moss grows more readily on the asbestos version, which many people liked because they were relatively strong. These sheets are quite large in contrast to tiles proper, which are small, heavy and made of fired clay. Apart from fibre-cement sheets it is also possible to get sheets made from steel or GRP.

"the older asbestos-cement sheets" are they safe??

"the older asbestos-cement sheets" are they safe??

No, they are prone to give off a fine dust if disturbed that can cause asbestosis and lung cancer. At the risk of being controversial, I would say that if left undisturbed the risk is very low. There are still loads of such sheets on garage roofs in European countries. One partial solution is a special paint-on sealer. Dismantling and removal is more risky - especially if you do any cutting with angle grinders etc. In the West this would be entrusted to a specialist firm with all the appropriate protection and the sheets would be sealed in plastic sheeting before safe disposal at an approved site.

P.S. After doing a quick search regarding the asbestos-cement sheets, I see they are still in common usage in China and India - so it isn't impossible that some may turn up in Thailand. Don't know if anybody in the building trade can advise.