DITRA is not intended to be barrier sound control system. DITRA does, however, provide a degree of sound attenuation similar to various thin-set sound control membranes. DITRA and ceramic tile were tested* over a 6" (152 mm)-thick concrete slab, and the measured IIC rating was 10 points greater than the measured IIC rating of the bare slab (IIC bare slab = 28, IIC slab w/DITRA and tile = 38). This level of performance is not sufficient to meet typical code requirements without additional sound control measures. The use of a sound control underlayment in combination with a load-distribution layer such as a mortar bed, lightweight concrete, or gypsum concrete can significantly improve the IIC rating of the assembly. Sound-rated ceilings can improve the IIC rating as well.
*Please note that this testing was performed prior to the approval of the ASTM E2179 standard test method and used a smaller specimen size (4ft x 4ft) than required by existing sound control method standards.(Since the sound testing was done with DITRA, Schluter Systems has developed DITRA-HEAT-DUO which has other sound control values (see the Schluter™-DITRA-HEAT-Installation Handbook for details).