Cleaning and Maintaining Acoustic Panels: Wood Wool, PET Felt and Wood Slat

8 август 2026 г.

Acoustic panels get specified, installed and then forgotten, which is mostly a compliment to the products. But facilities teams do eventually ask how to clean them, and the honest answer differs sharply by material. Worse, the instinctive approach, wiping a dirty surface with a wet cloth, is the one thing that ruins two of the three. Here is what actually works.

The principle behind all of it

Every one of these panels absorbs sound because air can move into its surface. Wood wool works because the fibre structure is open. PET felt works because it is porous. A slat panel works because the felt between the slats is exposed. Anything that seals that surface destroys the absorption, and unlike a scratch, it cannot be undone.

That single fact explains every recommendation below. Dry methods are safe. Wet methods risk clogging. Coatings are usually fatal. The goal of cleaning an acoustic panel is to remove what is sitting on the surface without filling the pores that make it work.

Wood wool cement board

The most robust of the three, because it is a mineral product. Cement-bound fibre does not attract static, does not shed and tolerates handling.

Routine: vacuum with a soft brush attachment, working along the fibre rather than against it. This is the whole maintenance regime for most installations, and on a high ceiling it is needed rarely.
Marks and scuffs: a stiff dry brush lifts most surface marks. Because the material is cement bound, you can be firmer with it than instinct suggests.
Heavier soiling: airless spray with a thin coat of matt water-based paint. This is the correct repair for a tired wood wool ceiling and it is why fifty-year-old installations are still in service.
Physical damage: panels are screw-fixed, so a damaged one unscrews and a replacement goes back in. No patching, no colour match across a whole ceiling.

What to avoid: rolling or brushing paint on. A roller pushes paint into the gaps between fibres and bridges them, and a bridged wood wool ceiling looks like wood wool while performing like a painted board. Two thin sprayed coats cost only a few percent of absorption. One rolled coat can cost most of it. Also avoid pressure washing, which erodes the fibre surface.

PET felt panels

Recycled polyester felt is genuinely easy, with one significant exception.

Routine: vacuum with an upholstery attachment. Felt does not fluff or shed, so this is quick.
Marks: dab with a barely damp cloth and mild detergent, then let it dry fully. Dab, do not rub, because rubbing works dirt deeper into the fibre and can fuzz the surface.
Sharp edges: a clean scalpel cut tidies a frayed edge neatly. PET felt cuts well, which is why it suits site-adjusted installations.

The exception is heat. PET is a thermoplastic. Steam cleaners, hot water extraction and anything that puts real heat against the surface will glaze or distort it permanently. There is no recovery from a glazed patch of felt, so keep steam away from it entirely. Solvent cleaners are the other thing to avoid, for the same reason.

Wood slat panels

These are two materials in one panel and each wants different treatment, which is where most mistakes happen.

The slats: dust with a dry microfibre cloth along the grain. For a veneered slat, an occasional wipe with a cloth barely dampened with water is fine. Furniture polish and silicone sprays are not, because they build a film that shows unevenly and attracts more dust than they remove.
The felt between the slats: this is the acoustic part, and it collects dust exactly where a cloth cannot reach. A vacuum with a narrow crevice tool run down the channels is the correct method. A soft paintbrush works for the last of it.
Never: soak the panel. The slats sit on an MDF core and the assembly is bonded to felt. Standing water swells the core and can lift the bond.

Damage to a single slat is the awkward case. Individual slats cannot practically be replaced, so a deep gouge usually means swapping the whole panel. This is an argument for ordering a small quantity of spares at the time of the original order, especially in a commercial fit-out where a matching batch may not be available in three years.

A quick reference

Vacuum with soft brush: safe on all three. This is the default and it handles ninety percent of maintenance.
Damp cloth, dabbed: fine on PET felt and on veneered slats. Not on wood wool.
Steam or hot water: never, on any of them. Worst on PET felt, where the damage is permanent.
Solvents: avoid on all three.
Rolled or brushed paint: destroys absorption on wood wool. Spray only.
Pressure washing: no, including on exterior installations.

Planning for it at specification stage

Two decisions at order time make maintenance much easier later. First, in a space that will get dirty, hallways, sports halls, entrances, put the harder-wearing material where hands and equipment reach and keep the delicate material high. Wood wool tolerates knocks that felt does not. Second, order spares. A pallet quantity almost always leaves offcuts, but a deliberate extra square metre or two of each finish, stored flat and dry, turns a future repair from a procurement exercise into an afternoon's work.

Choosing a material for a space that will need cleaning regularly? Tell us the room and the traffic and we will tell you honestly which of the three will still look right in five years. Browse the Sonablock wood wool collection for the most durable option in the range.