Acoustic panels and acoustic plaster are two ways to add sound absorption to a room, and the choice is about finish, buildability and budget rather than one being better than the other. Acoustic plaster is a near-seamless, monolithic render applied as a wet trade, hiding a porous absorptive layer behind a flush, joint-free surface; wood slat panels are a manufactured, demountable timber finish that absorbs through an exposed felt or mineral-wool backing. Both are porous absorbers that reduce reverberation and echo inside a room — neither blocks sound passing between rooms, which is soundproofing and depends on mass and construction. Compare them on appearance, installation, repair and demountability, reaction-to-fire class and cost, and judge either on absorption tested to a named report rather than a headline figure.
Acoustic panels vs acoustic plaster: two routes to absorption
Acoustic plaster and wood acoustic panels are two ways to add absorption to a room, and for a specifier the decision is about finish, buildability and budget rather than one being better than the other. Acoustic plaster is a near-seamless, monolithic render that hides a porous absorptive layer behind a flush, joint-free surface. A wood slat panel is a manufactured, demountable timber finish that absorbs through an exposed felt or mineral-wool backing.
Both are porous absorbers: they soak up sound energy to shorten reverberation time and cut echo *inside* a room. Neither is soundproofing — neither will stop sound passing *between* rooms, which depends on the mass and construction of the wall or floor, not on an absorptive finish. Confirm which problem you have before comparing the two, because an absorber of either kind will not quieten a neighbour.
How each one absorbs sound
The absorption route is broadly similar. Acoustic plaster works because its microporous finish coat is thin and open enough for sound to pass into a porous mineral substrate behind it, where the energy is absorbed. A slat panel works the same way in principle: sound passes between and around the slats into the acoustic backing — recycled-PET felt or mineral wool — that sits behind them, the same porous mechanism that makes acoustic panels work.
Because both rely on a porous layer, the figure that matters is the tested absorption for that exact build-up — the per-frequency data measured to ISO 354, and the αw single-number rating derived from it under BS EN ISO 11654, at the stated mounting — not a headline claim. Thickness, the depth of the substrate or backing, and any air gap all change the result, so compare like-for-like tested systems rather than assuming plaster and panels absorb the same across the spectrum.
Appearance: seamless plaster or expressed timber?
This is where they diverge most. Acoustic plaster reads as a continuous, minimalist surface with no visible joints or fixings; it can follow curves and wrap ceilings so the absorption is effectively invisible. A wood panel does the opposite — it expresses a warm timber texture, the rhythm of the slats and the coloured felt behind them, so the acoustics become a visible design feature. Both can be specified on walls or ceilings; the choice here is largely an aesthetic one.
Installation, repair and demountability
Acoustic plaster is a wet trade. It is applied on site by trained specialist applicators in several coats, needs drying and curing time, and its finish quality depends on workmanship, so programme and access matter — and much of its cost sits in that skilled labour. A slat panel is a dry fix, mounted mechanically to battens or a solid substrate, which is generally faster and less weather-dependent, though a timber panel is heavier than a plaster coat and needs a fixing that suits its weight.
Repair and demountability differ sharply. Damaged plaster usually has to be cut out and re-rendered, and matching texture and colour on a patch can be difficult; reaching services above a plastered ceiling means breaking into it. Slat panels can be demounted for access and individual sections replaced, which suits fit-outs where the ceiling void or wall behind must stay reachable. For many specifiers, that maintainability is the deciding factor.
Which has the better fire class, plaster or wood?
It depends on the material, and this is a real distinction for regulated spaces. Reaction to fire is graded by Euroclass under BS EN 13501-1 (A1 best to F worst), with smoke sub-classes s1–s3 and flaming-droplet sub-classes d0–d2 — see Euroclass reaction to fire explained. Because it is mineral-based, acoustic plaster generally sits in the higher, non-combustible reaction-to-fire classes.
Timber is combustible, so it needs scrutiny rather than assumption: untreated timber typically achieves around Class D, and reaching a higher class such as B-s1,d0 generally requires a fire-retardant treatment or specific construction, evidenced by a test report. Where a wall or ceiling lining must meet a set fire class — escape routes, schools, public buildings — read the classification on the report for either product rather than the marketing.
So which should specifiers choose?
It comes down to the brief, not a ranking. Acoustic plaster suits schemes wanting a seamless, minimalist finish over a mineral, non-combustible base, where the surface will not need to be demounted for access. Wood panels suit projects wanting visible warmth, faster dry installation and easy access to the void. Either way, follow the discipline in how to choose acoustic panels: match the tested absorption to the room's target, and where the result is set by regulation, have an acoustician model the space against measured data.
Frequently asked questions
Is acoustic plaster better than wood acoustic panels?
Neither is simply better; they are different finishes for the same job. Acoustic plaster gives a seamless, monolithic surface with hidden, generally non-combustible absorption but is a wet trade that is hard to alter later. Wood panels give a warm, demountable timber finish with visible felt and easier access and repair. Choose on appearance, buildability, maintainability and the tested absorption for each system.
Does acoustic plaster or wood panelling soundproof a room?
No. Both are absorbers that reduce echo and reverberation inside a room; neither blocks sound passing between rooms. Stopping sound through a wall, floor or ceiling is soundproofing, which depends on mass and construction and is governed by different standards, not by adding an absorptive finish of either kind.
Can acoustic plaster be repaired or removed later?
It is difficult. Damaged acoustic plaster usually has to be cut out and re-rendered, and matching the texture and colour of a patch can be tricky, while reaching services above a plastered ceiling means breaking into it. Wood slat panels, by contrast, can be demounted for access and individual sections replaced, which is why they often suit fit-outs that need future access.
Which has the higher fire class, timber or acoustic plaster?
Mineral-based acoustic plaster is generally non-combustible and sits in the higher reaction-to-fire (Euroclass) classes. Timber is combustible: untreated it typically reaches around Class D, and a higher class such as B-s1,d0 needs a fire-retardant treatment or specific construction proven by a test report. For any regulated lining, confirm the class on the report rather than assuming.