spenrock

Take a look at Rockwool ceiling insulation. It works as a great sound barrier/absorber, and will have the added benefit of insulation (keep cool air in) and is a fire barrier. Also, water will not destroy it, because it will not absorb, but eventually drain off. There is a specific type for ceilings. Make sure you ask for that and specify your main goal is soundproofing. You can also use it for wall insulation to achieve the same purposes. Google Rockwool in Thailand for info. It is sold worldwide, but I believe they have some manufacturing in Thailand.