Acoustic performance of concrete block partitions — how STC works for UAE office fit-outs
How sound transmission works for Tiger Stone hollow and insulated partitions, practical wall recipes for boardroom-grade acoustics, and how to get a verified rating for your assembly.
TL;DR — A plastered 200 mm hollow partition gives solid everyday acoustic separation; building the same wall with the insulated block improves it further thanks to the EPS core. For boardroom-grade isolation, use a double-leaf wall with an air gap and one leaf in solid block. A guaranteed STC rating belongs to a tested assembly, not to the block on its own — so commission a lab or field test on your specified build-up.
Why the EPS insert helps: the polystyrene core decouples the two concrete shells across the mid-frequency range, so speech transmission drops compared with a single-mass hollow assembly of the same thickness. This is consistent with the mass-spring-mass acoustic model, where two masses separated by a compliant layer outperform one solid mass of equal weight.
How STC is determined: Sound Transmission Class is a single-number rating derived from lab measurements of an assembly across standard frequency bands (per ASTM E90 / E413), or estimated in the field with ASTM E336. It describes the whole wall build-up — leaves, cavity, plaster, sealing and edges — not a single product. Two walls using the same block can land at very different STC numbers depending on detailing, so we do not quote a fixed STC for the block in isolation.
Practical recipes:
Standard office: 200 mm hollow + cement plaster both sides.
Quiet office / clinic: 200 mm insulated + plaster both sides.
Boardroom or recording: two leaves of 100 mm solid with an air gap, mineral wool in the cavity, double plaster on each face.
Caveats: lab ratings ≠ field results. Flanking paths through soffits, raised floors, return-air ducts and unsealed conduit penetrations dominate in the field. Specify acoustic sealant at all perimeters and seal every conduit head with intumescent putty. For a project requiring a guaranteed number, share your wall build-up with us and commission a lab or field test on the specified assembly — see /quote and /contact to arrange it.