Celenit vs Sonablock: Wood Wool Acoustic Panels Compared

If you are specifying mineralised wood wool panels in Italy, Celenit is usually the first name on the list. It is an established Italian manufacturer, it is written into countless capitolati, and most acoustic consultants know the range by heart.

Sonablock is a newer name. The panels are made by Stiga RM in Latvia and supplied across Europe by Wall Panels Pro. The material is the same family: spruce wood wool, mineralised and bound with Portland cement. The question a specifier actually needs answered is narrower than "which brand is better". It is this: at the mounting condition I am going to build, do the two products measure the same, and can I put the evidence in the project file?

This article answers both, using only published documents. Every number below is traceable to a named certificate, test report or EPD.

What the two products have in common

More than the marketing on either side suggests.

Both are wood wool cement board (WWCB) to EN 13168, and both the acoustic ranges are also declared to EN 13964 as suspended ceiling products. Both use Norway spruce. Both are bound with Portland cement, white cement in the finer decorative ranges. Neither uses formaldehyde binders. Both publish EN 15804+A2 Environmental Product Declarations and both hold PEFC chain of custody. Both carry Euroclass B-s1,d0 in their standard versions and offer an A2-s1,d0 variant.

So this is not a comparison between a proven material and an unknown one. It is a comparison between two manufacturers of the same well understood material, and the differences are in the detail.

The ranges, side by side

Celenit splits its range by wood wool width, which is what drives both the look and the acoustic behaviour. Sonablock does the same thing but names the fibre width directly.

	Wood wool width	Cement	Euroclass
Celenit N	3 mm	Grey Portland	B-s1, d0
Celenit A / AE	2 mm / 1 mm	Grey Portland	B-s1, d0
Celenit AB	2 mm	White Portland	B-s1, d0
Celenit ABE	1 mm	White Portland	B-s1, d0
Celenit AB/A2, ABE/A2	2 mm / 1 mm	White Portland plus mineral powder	A2-s1, d0
Sonablock Core Fiber 1.0	1.0 mm	White Portland	B-s1, d0
Sonablock Core Fiber 1.5	1.5 mm	White Portland	B-s1, d0
Sonablock Core Fiber 2.0	2.0 mm	White Portland	B-s1, d0
Sonablock FireSafe	1.0 / 1.5 / 2.0 mm	White Portland plus mineral powder	A2-s1, d0

The rough equivalences are Sonablock Fiber 1.0 to Celenit ABE, Sonablock Fiber 2.0 to Celenit AB, and Sonablock Fiber 1.5 sitting between the two with no direct Celenit counterpart.

Sound absorption at the same mounting condition

This is where most brand comparisons fall apart, because absorption figures for wood wool are meaningless without the mounting depth and the cavity contents. A 25 mm board fixed flat to concrete and the same board on a 200 mm plenum are different acoustic objects.

So here is the one condition where both manufacturers happen to publish: a 25 mm board with a 200 mm empty air gap behind it, tested in a reverberation room to EN ISO 354 and classified to ISO 11654.

Product	Test condition	Test body	Report or certificate	alpha w	Class
Celenit AB 25 mm	TH 225 mm, empty cavity	Istituto Giordano	331332-D	0.65 (H)	C
Celenit ABE 25 mm	TH 225 mm, empty cavity	Istituto Giordano	331334-F	0.65 (H)	C
Sonablock Fiber 1.5, 25 mm	ODS 200 mm, empty cavity	RISE Sweden	O100282-1356156	0.65 (H)	C
Sonablock Fiber 1.0, 25 mm	ODS 200 mm, empty cavity	RISE Sweden	O100282-1356156	0.60 (H)	C

Celenit's TH, total height, is measured from the soffit to the underside of the finish, so TH 225 is a 25 mm board on a 200 mm void. RISE's ODS is the distance from the floor of the chamber to the front face of the sample, so ODS 200 on a 25 mm board is the same geometry. The two are directly comparable.

The result is a tie. Sonablock Fiber 1.5 and Celenit AB and ABE all return a weighted absorption coefficient of 0.65 with an H shape indicator and land in Absorption Class C. Sonablock Fiber 1.0 comes in one step lower at 0.60, still Class C.

Nobody should be surprised by this. It is the same material at the same thickness on the same cavity. Physics does not care about the label. What it does mean is that any claim, from either side, that one brand fundamentally outperforms the other on absorption is not supported by the test data.

The air gap is doing most of the work

Worth dwelling on, because it is the single most common specification error with wood wool.

Celenit publishes an unusually complete set of results for AB at 25 mm, and reading them in order is instructive:

Mounting	alpha w	Class
Fixed flat, no cavity	0.45	D
30 mm cavity	0.45	D
100 mm cavity	0.60	C
175 mm cavity	0.60	C
200 mm cavity	0.65	C
400 mm cavity	0.60	C
30 mm cavity filled with 80 kg/m3 mineral wool	0.75	C
100 mm cavity, 60 mm of 40 kg/m3 mineral wool	0.90	B
200 mm cavity, 30 mm of 80 kg/m3 mineral wool	0.90	A

The board contributes a fairly narrow band of performance. The cavity, and above all whether you put mineral wool in it, contributes the rest. Going from a bare 25 mm board on the slab to the same board over a filled plenum takes you from Class D to Class A without changing the panel at all.

This matters commercially because Celenit's summary datasheets carry a headline of "alpha w up to 0.95" for AB and "up to 1.00" for ABE on the front page, without stating at the point of claim that those figures require 30 to 60 mm of rock wool at 40 to 80 kg/m3 behind the board. To be fair to Celenit, its website product pages do segment the claim properly, giving separate figures for direct fixing, empty cavity and filled cavity. The honest version exists. It is just not the one printed on the front of the datasheet, and it is not the one that ends up in tender documents.

Sonablock's published figure is the empty cavity figure: alpha w 0.65, Class C, bare panel on a 200 mm gap, tested by RISE under report O100282. Add mineral wool behind a Sonablock panel and it will climb the same way Celenit's does, for the same reason. Wall Panels Pro does not currently publish a filled cavity test, so we do not quote a filled cavity number.

If you take one thing from this article: compare products at the mounting condition you are actually going to build, and treat any absorption claim without a stated cavity depth as incomplete.

Fire performance

Both manufacturers offer a standard board at B-s1,d0 and a fire upgraded board at A2-s1,d0, both to EN 13501-1. Low smoke, no flaming droplets, in both cases.

The interesting part is what the A2 upgrade costs you in other properties, because both manufacturers achieve it the same way, by loading the board with mineral filler at the expense of wood.

	Mass at 25 mm	Thermal conductivity
Celenit AB, standard	12.0 kg/m2	0.070 W/mK
Celenit ABE, standard	12.0 kg/m2	0.075 W/mK
Celenit AB/A2, ABE/A2	15.3 kg/m2	0.100 W/mK
Sonablock Core, standard	10.5 kg/m2	0.070 W/mK
Sonablock FireSafe, A2	14.6 kg/m2	0.085 W/mK

Celenit's own EPD content declaration shows the mechanism plainly: calcium carbonate rises from 15 percent of the board by mass in AB to 30 percent in AB/A2, while wood falls from 38.1 percent to 27.7 percent. More stone, less wood, so a heavier board that insulates worse.

Sonablock's A2 route ends up lighter, 14.6 against 15.3 kg/m2, and holds a better lambda, 0.085 against 0.100 W/mK. On a large A2 ceiling, three quarters of a kilo per square metre and a 15 percent difference in conductivity are worth knowing about, particularly where the ceiling is carrying its own weight over a long span or where the buildup is contributing to a thermal calculation.

One caution on the standard boards. Sonablock's 10.5 kg/m2 is the mass declared in its verified EPD. Real delivered weight can run above the datasheet figure depending on moisture content at despatch, and anyone planning freight on a full truck should confirm the shipping weight with the supplier rather than working from a technical datasheet.

Thermal performance

Close enough that it rarely decides anything, but for completeness, declared lambda to EN 13168:

Celenit N 0.065, Celenit AB 0.070, Celenit ABE 0.075, Celenit A2 ranges 0.100. Sonablock Core 0.070 as declared in its EPD, with the technical datasheet quoting an average of 0.067 depending on specification, and Sonablock FireSafe 0.085.

Celenit N is the best insulator of the group. It is also the one board here that declares no sound absorption performance at all, so think twice before specifying it for acoustics.

The carbon question, answered honestly

Both manufacturers publish third party verified EPDs to EN 15804+A2 under the International EPD System, both under PCR 2019:14. Celenit's acoustic ranges sit under EPD-IES-0025754. Sonablock Core is EPD-IES-0031288 and FireSafe is EPD-IES-0031289.

We are not going to claim a carbon advantage we cannot support. The published figures do not give Sonablock one.

For the product stage, modules A1 to A3, per square metre of 25 mm board, Celenit AB declares a GWP-total of minus 1.07 kg CO2 equivalent. Sonablock Core declares 6.96 kg CO2 equivalent. That looks like a rout, and it is not, because the two EPDs treat biogenic carbon differently. Celenit's declaration credits the carbon stored in the spruce as a negative in the product stage and then releases it at end of life, where its C4 figure is 6.44. Sonablock's declaration does not take the uptake credit in A1 to A3, and correspondingly its C4 is only 0.371.

Compare the whole life cycle instead and the gap narrows a great deal. Summed across the published modules, that is roughly 7.9 kg CO2 equivalent cradle to grave for Celenit AB against 9.4 for Sonablock Core, the latter stated as a total in its own EPD. Celenit is still ahead, by something like 15 percent.

Two things are worth adding, not as excuses but because they are in the documents. Sonablock's board stores slightly more biogenic carbon per square metre than Celenit's, 1.99 against 1.81 kg of carbon, despite being the lighter board. And EN 15804 itself warns that EPDs are only strictly comparable when the declared units, system boundaries and modelling choices align. These two do not align on biogenic accounting, so the honest summary is that both products are low impact mineral bound timber products with verified declarations, and that Celenit's published cradle to grave number is currently the lower of the two.

If carbon is the deciding criterion on your project, read both EPDs rather than either manufacturer's summary of them. Links are at the end.

What you can actually download

This is the clearest practical difference between the two, and it is the one that tends to matter when a project file is being assembled or a client's technical reviewer starts asking questions.

Celenit publishes a certificate number for every acoustic test it has ever commissioned, and there are around seventy of them across thicknesses, cavity depths and cavity fills. That library is a real asset, genuinely deeper than anything Sonablock has. What Celenit does not publish is the reports themselves. Its public download area carries brochures, technical manuals and datasheets. There is no downloadable EN ISO 354 test report, no Declaration of Performance, no CE certificate, and no EN 13501-1 classification report. The fire class appears on every document without a classification report number attached to it anywhere.

Sonablock publishes the documents. The full RISE report O100282 is a downloadable PDF with the one third octave curve, the reverberation room dimensions, temperature and humidity at the time of test, the instrument list and the signatures of the two RISE engineers who ran and checked it. Alongside it sit the CE marking certificate, the Declaration of Performance, the reaction to fire classification report K25/2026, the PEFC chain of custody certificate with its expiry date, the safety data sheet, both EPDs and the technical datasheets for each thickness.

For a specifier this is a practical distinction rather than a moral one. Celenit has tested far more configurations than Sonablock. Sonablock will hand you the evidence for the configurations it has tested, in a form you can forward to a client or attach to a submittal without asking anyone's permission.

Looking for a Celenit alternative?

People arrive at this question from a few different directions, and the right answer depends on which one you are in.

You need the same measured absorption at a lower cost. This is the strongest case for Sonablock. At 25 mm on a 200 mm empty cavity the two products return the same alpha w 0.65 and the same Absorption Class C, from accredited laboratories, to the same standard. Celenit's January 2023 list prices for 25 mm natural board with a straight edge are 27.24 EUR per square metre for AB and 32.69 for ABE, before edge profiling, which adds between 4.20 and 8.69 EUR per square metre depending on profile and quantity, and before colour. Sonablock is quoted per project. Ask for both and compare the delivered number.

Lead time or availability has become a problem. Sonablock is made to order in Latvia with direct factory scheduling rather than distributor stock allocation, which tends to help on larger orders and on non standard sizes and colours.

You need a size, colour or shape that is not in the standard catalogue. Custom RAL and NCS colours, printed faces, custom dimensions and the Design range of shaped and grooved panels are all made to order.

You have been quoted Celenit N and expected acoustic performance. Read the next section carefully, because this is the most expensive mistake in the category.

Where Celenit is the better choice

We sell Sonablock, and we are still going to say this clearly, because sending a specifier down the wrong road costs everyone more than a lost order.

Italian public procurement. Celenit holds natureplus, ANAB and ICEA credentials and has an established CAM compliance position for Italian public works. Worth noting that its natureplus certification covers the cement bound B class boards and not the A2 fire upgraded range, so check which certificate your tender actually calls for. If the job is gated on CAM Edilizia, confirm the route for any alternative product before you substitute, not after.

An unusual mounting condition. Celenit's certificate library covers thicknesses from 15 to 50 mm, cavity depths from zero to 400 mm, and a wide range of mineral wool fills at stated densities. Sonablock currently publishes one acoustic report, at one thickness, at one mounting depth, for two fibre widths. If your ceiling is a 125 mm plenum with 60 mm of 40 kg/m3 rock wool, Celenit has tested exactly that and Sonablock has not.

A filled cavity where you need the number in writing now. Same reason. Sonablock's panels will behave like any other WWCB over a filled plenum, but we are not going to quote a figure we cannot hand you a report for.

T-grid systems with a specific edge detail. Celenit publishes a full edge availability matrix against thickness, including rebated profiles engineered for T24 and T35 grids. Note that all of Celenit's rebated profiles require a minimum board thickness of 25 mm, so if you are working at 15 mm, neither manufacturer will give you a rebated edge.

Decades of specification history. If an acoustic consultant has modelled a room using Celenit data from a previous project, the path of least resistance is usually to build what was modelled.

How to specify either product properly

Whichever you choose, a wood wool specification is incomplete without four things, and most of the disappointing rooms we hear about are missing at least one.

State the board thickness. State the cavity depth. State whether the cavity is empty or filled, and if filled, the thickness and density of the mineral wool. Then state the alpha w and absorption class you expect at that exact buildup, with the certificate number that supports it.

If a supplier gives you an absorption figure without a mounting condition attached, ask for the condition before you compare it with anything.

Summary

At 25 mm over a 200 mm empty cavity, Celenit AB, Celenit ABE and Sonablock Fiber 1.5 all measure alpha w 0.65 and Absorption Class C, certified to the same standard by accredited laboratories. That is the comparison that matters and it is a tie.

Around that tie, Celenit brings a much larger library of tested configurations, established Italian procurement credentials and a slightly better published cradle to grave carbon figure. Sonablock brings a lighter and thermally better A2 board, a complete and downloadable evidence pack, made to order flexibility on size and colour, and a lower cost per square metre.

Neither of those lists is a reason to dismiss the other product. They are the actual trade off, and which side of it you want depends on the project.

Sources

Sonablock documentation, including the full RISE report, is published at wallpanelspro.com Sonablock documentation.

• Sound absorption, Sonablock: RISE Research Institutes of Sweden, report O100282-1356156, 3 March 2026, to SS-EN ISO 354 and SS-EN ISO 11654
• Reaction to fire, Sonablock: classification report K25/2026 to EN 13501-1
• Sonablock EPD, Core range: EPD-IES-0031288, version date 15 April 2026, valid to 14 April 2031
• Sonablock EPD, FireSafe range: EPD-IES-0031289, version date 15 April 2026, valid to 14 April 2031
• Sonablock PEFC chain of custody: BMCERT-PEFC-COC-00175, valid to February 2028
• Sound absorption, Celenit AB 25 mm at TH 225 empty cavity: Istituto Giordano certificate 331332-D, 11 February 2016
• Sound absorption, Celenit ABE 25 mm at TH 225 empty cavity: Istituto Giordano certificate 331334-F, 11 February 2016
• Celenit AB mounting series at 25 mm: Istituto Giordano certificates 331332-A to 331332-E, 333104-A, 324214-B, 324215-B, 324215-D, 324215-E
• Celenit EPD, AB and ABE ranges: EPD-IES-0025754
• Celenit technical data and mass, thermal conductivity, edge availability: CELENIT AB and CELENIT ABE schede tecniche ed. 2021/07, and Acoustic Design technical manual
• Celenit list prices: LISTINO PREZZI Gennaio 2023, ed. 00 rev. 00, in force from 1 January 2023