The Multifunctional Underroof Board

Kronotec DP50 is an MDF-panel that is open to vapour diffusion for use as an under panel for roofing.

Previously it was necessary to lay a film that was open to diffusion or prefabricated bituminous surfacing on to board shuttering, in order to guarantee protection from rain.

Kronotec DP50 takes over all functions.

This results in considerable savings in working time, material expenditure and material costs, for example the panels can be laid faster than individual boards.

The LiquiSafe tongue and groove shaping means that exact fitting is possible this guarantees the roof is windproof and there is no need to glue the joints.

Kronotec DP50 withstands tread in a dry state up to a rafter spacing of 100.0 cm.

LiquiSafe Protects the Building Frame

At roof pitches of just 15° or more, the application-friendly LiquiSafe tongue-and-groove system is watertight, thus protecting the building frame. This eliminates the need for additional boarding and a water- vapour-permeable membrane or multiple plies of bitumen to keep out rainwater. KRONOTEC DP50 performs all of these functions and is also faster to lay than individual boards. When dry, the boards are puncture-resistant up to a rafter spacing of one metre.

Applications

• Underroof panelling (class UDP-A as defined by the German Roofing Association)
• Outer boarding for walls of timber-frame houses

KRONOTEC DP50 has been approved by the state Deutsches Institut für Bautechnik in Berlin for stiffening applications.

KRONOTEC WP50 is an MDF-panel that is open to vapour diffusion for use as external panelling of walls in wood post and lintel construction. Contrary to an Kronoply OSB-panel that is vapour diffusion resistant, the WP50 guarantees construction security, as possible humidity that could get into the wall construction is diffused outwards without any problem.

Kronotec WP50 is building inspection approved and therefore is approved for use for reinforcing the wall construction. Tests show that where a façade is ventilated at the rear no film need be applied to the wall panel.



Nominal board thicknesses [mm]	d	12-15
Strength values [N/mm²]
Stresses on board
Bending	fm,k	17.0
Shear	fv,k	0.8
Plate loading
Bending	fm,k	9.4
Tensile force	ft,k	9.5
Compression	fc,k	7.5
Shear	fv,k	5.5
Stiffness values [N/mm²]
Stresses on board
Modulus of elasticity	Em,meana	2700
Shear modulus	Gmeana	50
Plate loading
Modulus of elasticity	Em,meana	1300
Modulus of elasticity Tensile force	Et,meana	1300
Modulus of elasticity Compression	Ec,meana	1300
Shear modulus	Gmeana	600
a The characteristic stiffness values E05 and G05 are calculated as follows: E05 = 0.85 x Emean and G05 = 0.85 x Emean
General and building physics values
Bulk density acc. to EN 323	m	510 - 550 kg/m³
Max. deviations in board thickness		± 0.5 mm
Embedment strength	fh,k	18.0 N/mm
Thermal conductivity acc. to EN 13986	λ	0.09 W/mK
Water vapour permeability value	μ	11
Thickness swelling acc. to EN 317		≤ 6.5 %
Emissions class		E1 – 100% formaldehyde-free binders
Utilisation classes acc. to EN V 1995-1-1		1 + 2
Flammability class		B2 - normal combustibility
Applicable German technical approval		Z-9.1-442

Delivery programme DP50, LiquiSafe, T + G on all four edges

Format [mm]	Thickness [mm]
	15
2500 x 675	•

Delivery programme WP50, square edge

Format [mm]	Thickness [mm]
	15 U/p
2650 x 1247 (Special formats on request)	60
2800 x 1247	60

Transport and Storage

KRONOTEC DP50 must be

• protected at the edges to prevent damage,
• protected from excessive moisture and prolonged exposure to the elements,
• covered when stored at construction sites,
• placed on top of wooden blocks to avoid direct contact with the ground and prevent moisture from rising through the pile,

• acclimated before installation; store the boards for about three days beforehand without the plastic wrapping under the same climatic conditions as at the installation site and
• installed while dry (important!) unless the panels can release their moisture right after being installed; if panels have become moisture, they dry out again without losing any of their strength.

Use

• Roof type: Class UDP-A acc. to the guidelines of the German Roofers’ Association (ZVDH)
• Roof pitch: It may be between 8° and 16° less than the standard pitch for the tiles.
• Safe from puncturing: Up to a rafter spacing of 1000 mm
• Weathering: Boards may be exposed to the elements for up to 4 weeks. Moist panels are not safe from puncturing.

• Attachment: Use staples, screws or nails.
• Sealing: Use only butyl rubber tape; no priming is required.
• Interior use: To prevent condensation, complete the construction right after installing the roof boards.
• Any moisture must be able to escape by venting.
• Execute the required airtight building shell with care.
• “Cold roofs”: with uninsulated constructions, ensure adequate ventilation of the area beneath the roof.