The material used to make KRONOPLY MAGNUM BOARD is KRONOPLY OSB/4 sanded. This certified, food-safe wood-based material is characterised by minimal swelling and shrinkage when exposed to moisture. It is produced using only thinnings from managed German forests. Completely formaldehyde-free binders are used to achieve highly stable bonding of the raw materials. The solid KRONOPLY MAGNUM BOARD building system consists of 25-mm-thick KRONOPLY OSB/4 boards glued together.

Dimensionally Stable and Certified

KRONOPLY MAGNUM BOARD, like KRONOPLY OSB/4, is extremely dimensionally stable, structurally very strong, and excellently suited for thermal and acoustic insulation and fire protection. Planned apertures for stairways, windows and doors, electrical conduits and sanitary and heating installations are cut out and precisely milled to the required sizes and shapes prior to gluing. The boards are pressed to thicknesses from 75 to 250 mm with between three and ten plies.

The final sizes are freely selectable. Every element of the KRONOPLY MAGNUM BOARD wood building system is covered by technical approval no. Z-9.1-591 of the German state Deutsches Institut für Bautechnik in Berlin.

Production of Large Wall and Roof Elements

KRONOPLY OSB/4 is produced as long boards measuring 15 x 2.8 metres, with a thickness of 25 mm and sanded surfaces. This innovative KRONOPLY OSB product is optimally suited for making large wall and roof elements for prefabricated and built houses. It offers producers of prefabricated components for timber-frame houses many opportunities to work more efficiently and economise. Storey-high long boards of the KRONOPLY OSB product family can cover the entire length of buildings, yielding airtight constructions that are free of butt joints. Externally applied thermal insulation prevents thermal bridges and maximises the associated energy savings.



		Strand direction
		Major axis	Minor axis
Nominal board thicknesses [mm]	d	25	25
Strength values [N/mm²]
Stresses on board
Bending	fm,k	27.5	19.0
Shear	fv,k	1.5	1.5
Plate loading
Bending	fm,k	10.9	8.0
Tensile force	ft,k	11.5	11.0
Compression	fc,k	14.5	14.5
Shear	fv,k	7.0	7.0
Stiffness values [N/mm²]
Stresses on board
Bending modulus of elasticity	Em,meana	7500	3500
Shear modulus	Gmeana	70	90
Plate loading
Tensile modulus of elasticity	Et,meana	3500	3000
Bulk modulus of elasticity	Ec,meana	3500	2500
Shear modulus	Gmeana	1100	1100
a The characteristic stiffness values E05 and G05 are calculated as follows: E05 = 0.9 x Emean and G05 = 0.9 x Emean
General and building physics values
Bulk density acc. to EN 323	m	620 kg/m³
Max. deviations in board thickness		± 0.8 mm
Embedment strength acc. to EN 1087-1	σZy	0.13	0.13
Thermal conductivity acc. to EN 13986	λ	0.13 W/mK
Water vapour permeability value	μ	200 / 300
Change in length when rel. humidity increases/decreases	%/%	0.005
Thickness swelling acc. to EN 317		≤ 8 %
Emissions class		E1 – 100% formaldehyde-free binders
Reaction to fire performance class acc. to EN 13501-1		1 + 2
Flammability class to EN 13501-1		B - s2, d0
Applicable German technical approval		Z-9.1-503

Format [mm]	Thickness [mm]
	25
15000 x 2800	•

Interior Coating – Everything Is Possible

KRONOPLY MAGNUM BOARD elements have a sanded surface that can be directly painted, papered, smoothed with levelling compound, plastered or finished with a veneer, laminate, etc. Depending on the stresses they will be subjected to, it is also possible – but not essential – to cover them with plasterboard.

Laying and Boarding

• For interior or exterior boarding applications, leave expansion joints at least 3 mm wide between boards.
• When laid closely with butt joints in interior walls, leave room for expansion where the boards adjoin other structures.
• The storey-high formats are produced with a slightly reduced width (of 1247 mm) to allow for expansion.

Coating and Varnishing

• KRONOPLY OSB with a ContiFinish^® surface may be coated with a solvent-containing PU (DD) or synthetic-resin varnish.
• Sanded surfaces may be coated like normal wood (e.g. with varnishes, paints, oils, waxes and glazes).
• It is advisable to apply at least three coats, sanding after the first one.
• Application of at least three coats is recommended.
• The only way to achieve an absolutely smooth surface is to apply filler.

Transport and Handling

• Take steps to prevent the boards, and especially the unprotected edges, from absorbing large amounts of moisture during transport and installation. Be careful not to damage the edges when lifting, moving and stacking boards (this applies especially to tongue-and- groove boards).
• Check against the labels or producer’s documentation on-site to make sure that the following are correct: thickness, approved utilisation class, surface (sanded or ContiFinish®) and edge type (square-edged or tongue-and-groove).
• During installation, boards may be briefly leaned against a solid structure at a 70° angle.
• Always carry individual boards in an upright (vertical) position.

Storage

• Protect boards from exposure to significant moisture or very high relative humidity.
• Prevent direct contact of the boards with the floor. ■ Only store outdoors temporarily, and if unavoidable cover stacks with watertight but water-vapour-permeable tarpaulins.
• Always stack boards horizontally on pallets and wooden supports (spaced no more than 600 mm apart).
• Align wooden supports precisely with one another and parallel to the shorter side of the boards.
• Lay the boards so their edges line up (with a maximum overhang of 15 mm).

Acclimatisation

• Precondition boards prior to installation.
• Store boards for about three days under the same climatic conditions that prevail at the installation site.
• This adjustment to the ambient moisture at the installation site will prevent excessive shrinkage or swelling.

Sawing, Milling, Sanding and Drilling

• KRONOPLY OSB can be sanded, sawn, milled and drilled just like solid wood and using all of the same tools.

Nailing, Stapling, Screwing and Gluing

• KRONOPLY OSB can be attached to wooden studs and rafters using screws, nails or staples.
• Use in accordance with the official approvals and standards (Z-9.1-618, Z-9.1-503 and DIN 1052 in Germany as well as EN 1995-1-1 (EC 5)).
• Additionally bond or glue tongue-and-groove joints.