This research aims to develop the coconut coir and fiber indoor acoustic and thermal insulation boards mixed with natural latex. The 5 ratios of coconut coir: coconut fiber: natural rubber were equal to 0.1: 0.9: 0.1 0.1: 0.9: 0.15 0.1: 0.9: 0.2 0.1: 0.9: 0.25 and 0.1: 0.9: 0.3 by weight. The indoor acoustic and thermal insulation boards were produced by knitting the coconut coir and fiber spraying the natural latex and heat compressing. The properties testing of indoor acoustic and thermal insulation boards included the density test water absorption test tensile strength test thermal conductivity test sound protection efficiency test and real usage test. From the results 0.1: 0.9: 0.15 ratio is the most suitable ratio of coconut coir and fiber indoor acoustic and thermal insulation board mixed with natural latex. The natural latex which putted in these indoor acoustic and thermal insulation boards can reduce the water absorption and increase tensile strength and sound protection efficiency.

This research aims to develop the coconut coir ceiling board mixed with natural latex. The 6 ratios of gypsum plaster: coconut coir: sodium silicate: natural rubber: tap water are equal to 1: 0.15: 0.03: 0.00: 1 1: 0.15: 0.03: 0.01: 1 1: 0.15: 0.03: 0.02: 1 1: 0.15: 0.03: 0.03: 1 1: 0.15: 0.03: 0.04: 1 and 1: 0.15: 0.03: 0.05: 1 by weight. The ceiling boards were produced by casting in normal temperature (30 – 35 degree of Celsius). The properties testing of coconut coir ceiling board mixed with natural latex followed the TIS 219-2009 standard (gypsum plasterboard) including: breaking load nail pull resistance deflection water absorption density thermal conductivity coefficient and real usage. From the results 1: 0.15: 0.03: 0.03: 1 ratio is the most suitable ratio of coconut coir ceiling board mixed with natural latex. This developed ceiling boards can reduce the quantity of coconut coir waste and get the good thermal insulation ceiling board products.