Sound insulation compared
Acoustic Screed vs Standard Liquid Screed
Any conversion creating separate dwellings needs sound insulation between floors that meets Part E. Here's how an acoustic screed build-up differs from a standard one.
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Standard liquid screed is specified for strength, flatness and thermal performance. Acoustic screed build-ups are specified for exactly the same reasons — plus a resilient layer designed to control impact and airborne sound transmission between floors, which matters the moment you're creating separate dwellings.
The screed itself is often the same product; what changes is the layer underneath it and the detailing at the perimeter, both of which are what actually deliver the acoustic performance.
This page explains the differences, when Part E of the Building Regulations applies, and what an acoustic build-up looks like in practice.
What actually makes a screed 'acoustic'
There's no such thing as an acoustic screed mix in isolation — acoustic performance comes from the whole floor build-up. A resilient acoustic layer (mineral wool slab or proprietary acoustic membrane) sits beneath the screed, isolating it from the structural floor and breaking the path for impact sound.
Perimeter isolation strips, careful sealing of any penetrations, and avoiding rigid bridges between the screed and surrounding walls are just as important as the resilient layer itself — a single rigid bridge can undo the acoustic performance of an otherwise correct build-up.
Build-up comparison
| Layer | Standard vs acoustic |
|---|---|
| Sub-layer | Rigid PIR/EPS insulation vs resilient acoustic mineral wool or membrane |
| Perimeter detail | Standard foam expansion strip vs full-height isolation strip, no rigid bridging |
| Screed itself | Same liquid screed product in most cases either way |
| Testing requirement | None vs pre-completion sound testing (or robust detail) under Part E |
Converting a property into flats?
Tell us about the conversion and we'll confirm the acoustic build-up needed to meet Part E, priced alongside the screed.
When Part E acoustic requirements apply
- New-build flats and any conversion creating separate dwellings
- Houses converted into flats or maisonettes
- Any floor separating one dwelling from another, including the roof void above
If you're building or converting to create separate dwellings, you need the acoustic build-up — it's a regulatory requirement, not an optional upgrade. For a single dwelling with no separation floor, standard screed is all that's needed.
— Exeter Liquid Screeders
Acoustic Screed vs Standard Screed — questions we get asked
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Converting a property into flats?
Tell us about the conversion and we'll confirm the acoustic build-up needed to meet Part E, priced alongside the screed.