What is a cement-bonded particle board?

What is a cement-bonded particle board made of?#

A cement-bonded particle board is a pressed building board in which graded wood chips are bound with Portland cement, water and a small amount of hydration additives. It should not be confused with conventional particleboard, OSB, plasterboard or fibre cement, which are all built up differently.

The wood chips add lower weight, toughness and workability. The cement matrix provides hardness, dimensional stability and resistance to moisture, frost, mould and fire. The result is a dense, robust board that works both as a visible material and as a technical layer in a complete assembly.

CETRIS is made by CIDEM Hranice a.s. in the Czech Republic. The base product is CETRIS BASIC. The other products use the same material and differ through sanding, profiling, perforation, edge milling or a factory-applied finish. The ECO variants also contain 4 per cent by weight of processed waste from the manufacturer’s own production.

How is the board made?#

Production starts with timber that is chipped and graded to a controlled particle size. The chips are mixed with cement, water and additives and pressed into large boards. As the board cures, the cement reacts with the water and forms a rigid mineral matrix around the wood chips.

The boards are then cut to format and, where required, sanded, milled, drilled or finished. This structure explains why the material behaves differently from both wood panels and pure cement products: it can be worked on woodworking machines, but its density and cement content call for carbide tools and effective dust extraction.

What properties does cement-bonded particle board have?#

The material is heavier than plasterboard and OSB, but the weight comes with a hard surface, good impact resistance and a dimensionally stable board for demanding environments. A 12 mm CETRIS BASIC weighs 17.4 kg/m², and a full 1,250 × 3,350 mm board about 73 kg.

• Fire: standard untreated boards are classified A2-s1,d0 under EN 13501-1.
• Moisture: thickness swelling after 24 hours in water is at most 0.28 % according to the manufacturer.
• Frost: the board is tested over 100 freeze–thaw cycles to EN 1328.
• Sound: the solid board provides 30–35 dB airborne sound insulation depending on thickness.
• Mould and insects: the high alkalinity and low nutrient content of cement make the board hard to attack.
• Content: the boards contain neither asbestos nor formaldehyde.

These properties belong to the board itself. A badly built wall does not become moisture-safe just because the board tolerates moisture: timber framing, insulation and other layers behind it can still be damaged. The board must therefore sit in an assembly with proper drainage, ventilation, junctions and drying capacity.

How does it differ from plasterboard?#

Plasterboard is lighter, cheaper and quicker to cut for ordinary interior work. It gives smooth walls and belongs to well-developed systems for dry rooms and fire protection; standard 12.5 mm plasterboard is commonly classified A2-s1,d0.

Cement-bonded particle board is chosen when the surface must take harder impact, more moisture, exterior exposure or fixings that do not suit a paper-faced board. The trade-off is higher weight, more demanding cutting and stricter dust control. The two often complement each other: plasterboard provides an economical interior lining while CETRIS takes the exposed or mechanically loaded position.

How does it differ from fibre cement?#

Fibre cement is a cement-based board reinforced with fibres instead of wood chips. Products vary widely: some are facade panels, others thin wind barriers or very hard fire-protection boards. A fibre-cement board may reach class A1 and be thinner than CETRIS, but it can also have more brittle edges, need a proprietary fixing system or be meant for a narrower function.

CETRIS can be easier to work with as a thick, self-supporting building board. Neither material family is always better: compare the exact product’s density, bending strength, fire class, moisture exposure, fixing system, format and documented use.

How does it differ from OSB?#

OSB is made of oriented wood strands bonded into a stiff structural panel. It is much lighter, often cheaper, easy to screw into and efficient for racking resistance in timber construction. Typical OSB/3, however, is classified D-s2,d0 from 9 mm and swells more under prolonged water exposure than CETRIS BASIC, according to each manufacturer’s declared values.

CETRIS becomes the better fit when reaction to fire, moisture, frost, impact and a cement-based surface matter more than low weight and fast installation. OSB can still be the right choice in a dry, protected timber assembly where low dead load and easy fixing come first. Specialist and fire-retardant OSB can have other classes.

What do A2-s1,d0 and EN 13986 mean?#

CETRIS cement-bonded particle boards are declared under the harmonised standard EN 13986:2004+A1:2015 for wood-based panels in construction. The declaration of performance covers non-load-bearing use and, from the stated thickness, load-bearing use in dry or humid conditions. EN 634-1 and EN 634-2 set the requirements and tests for cement-bonded particle boards.

Reaction to fire is classified under EN 13501-1. A2-s1,d0 means a very limited contribution to fire, very limited smoke production and no flaming droplets in the test. The class says nothing about how long a wall resists fire. Fire resistance is given instead as EI or REI and applies to the complete tested or assessed construction.

Surface treatment affects the class. Standard untreated products such as BASIC, PD, PDB, PDP, PROFIL and AKUSTIC are A2-s1,d0, while factory-finished products and the ECO variants are B-s1,d0 according to their data sheets. Never copy a class from another CETRIS product. The same goes for sound: 30–35 dB airborne sound insulation for a solid board is not the same as sound absorption by perforated AKUSTIC boards.

Where is cement-bonded particle board used?#

The material is used where an ordinary interior board is too vulnerable or several requirements have to be met at once. Each area has its own demands, so the same board and fixing method do not suit every job.

• Walls and shafts: robust lining, racking action and documented fire and acoustic systems.
• Ventilated facades: a visible layer with open joints on a correctly ventilated supporting structure.
• Floors: tongue-and-groove PD and PDB for dry floor systems, half-lapped PDP for lightweight floating floors on insulation.
• Roofs and ceilings: load-bearing or protective layers where span and fixing are verified.
• Fire protection: linings to steel and timber structures in systems with a documented EI or REI rating.
• Balconies, plinths and permanent formwork: a moisture-resistant board with the right thickness, edge treatment and fixing.

How is the board machined and installed?#

The boards can be sawn, drilled, milled and sanded, but cement wears tools faster than timber. Saw blades and cutters should be carbide or diamond, while HSS bits are fine for drilling. Machining creates fine mineral dust, so size the extraction for it and wear respiratory protection.

Pre-drill and countersink to suit the chosen screw and board. Facades use oversized holes, washers or rivets so the board can move; rigid fixing can cause cracking. Large boards are heavy and should be carried upright by several people or handled mechanically. Store them flat, dry and under cover before installation – the transport foil is not long-term weather protection.

An untreated board may at first show a whitish film of free lime. This is normal and fades over time. Cut edges on finished boards should be cleaned and sealed straight after cutting.

How do I choose the right CETRIS board?#

Start with the function, not the product name. Should the board be load-bearing, visible, weather-exposed, fire-classified, sound-absorbing or a floor? Then set the exposure, support spacing, loads, required appearance and joint design.

• BASIC – the smooth untreated base board for walls, facades, roofs and fire protection.
• PD and PDB – tongue-and-groove floor boards; PDB is also sanded to ±0.3 mm.
• PDP – a floor board with a 45 mm half-lap for lightweight floating floors.
• PROFIL – an untreated board with a relief surface imitating wood or slate.
• AKUSTIC – a perforated board for sound absorption, mean coefficient 0.61–0.69.
• LASUR, PROFIL LASUR and the FINISH variants – factory-finished boards, mainly for facades.
• ECO BASIC and ECO PDB – with 4 % recycled material and reaction-to-fire class B-s1,d0.

What should the specification say?#

A useful specification says more than “cement board”. State the product or verifiably equivalent performance, thickness, format, edge profile, finish and reaction-to-fire class. Add the supporting structure, centres, fixing type, hole diameter, edge distances, joint width and movement joints.

Exterior work should define ventilation, cavity, flashings and drainage. Fire-rated work needs the exact build-up, number of board layers, insulation and EI or REI rating, and floors need load, supports, joint layout and flatness. Refer to dated documents, because web pages and data sheets change. If a characteristic is missing from the declaration of performance, do not fill the gap with an assumption – ask for supporting documentation.

Summary#

Cement-bonded particle board sits between wood-based panels and cement products, but should be judged as a material in its own right. It is heavier and harder to work than plasterboard or OSB, yet offers an unusually useful combination of moisture resistance, impact strength, dimensional stability and limited contribution to fire.

The CETRIS range uses the same material in walls, facades, floors, roofs and fire protection, but the products are not interchangeable without checking. The process is always the same: define the requirements, choose a documented product and system, verify the details, and order once thickness, format, processing and delivery are settled.