Cem Topped Board

Sika Liquid Plastics’ Cem-topped Board is chemically inert and safe to use (please refer to the relevant safety data sheet before use)

• Fire behaviour according BS476 Part 3 FAA rating
• Water Vapour Resistance  BS EN 12086: 1997

Rigid polystyrene insulation board

Product does not expire if correctly stored

The packaging for Sika Liquid Plastics’ Cem-topped Board should not be considered adequate for long term outside protection.  Ideally boards should be stored inside a building.  Sika Liquid Plastics’ Cem-topped Boards should be stored flat in a ventilated areas and protected generally from accidental damage, contact with volatile solvents, flames and extended exposure to UV and sunlight.  If it is stored outside for more than a few weeks, it must be covered with a pale pigmented plastic sheet.

The thermal resistance (R value) varies with the thickness and is calculated by dividing the thickness of the individual component (expressed in metres) by its thermal conductivity.

Additionally, an allowance of the calculated resistance is made to compensate for saturated roofs during long periods of rain in accordance with BS EN ISO 6946: 1997 and BRE report (BR443 2006). Conventions for U-value calculations.

*Product thickness = insulation thickness + 10mm polymer fibre reinforced cement topping

Thermal Conductivity
The thermal conductivity of the cement topping of Liquid Plastics’ Cem-topped Board is 1.4 W/m.K.

The thermal conductivity of the extruded polystyrene core of Liquid Plastics’ Cem-topped Board is 0.029 W/m.K

Thermal Resistance
The thermal resistance (R value) varies with the thickness and is calculated by dividing the thickness of the individual component (expressed in metres) by its thermal conductivity.

Additionally, an allowance of the calculated resistance is made to compensate for saturated roofs during long periods of rain in accordance with BS EN ISO 6946: 1997 and BRE report (BR443 2006). Conventions for U-value calculations.

The linear thermal expansion coefficient of the rigid extruded polystyrene insulation element in Liquid Plastics’ Cem-topped Board is 0.07mm/m.K  when tested to BS 4379-3: 1988 (1996) (Methods of test for rigid cellular.

When subjected to British Standard fire tests using Sika Liquid Plastics’ Cem-topped Board, the results are dependent on the roofing system adopted, however Decothane systems used as the waterproofing layer of the complete system achieves a FAA rating for BS476 Part 3.  Decothane is also successfully tested to DD ENV 1187 Parts 1, 2 and 3 and FM (Factory Mutual).

The rigid polystyrene insulation element of the Sika Liquid Plastics’ Cem-topped Board is not sensitive to moisture of any kind. Its surface is water repellent and there is no capillary suction.  The material is also not hygroscopic.  Water absorption is <0.5% when tested to BS EN 12087: 1997 (Thermal insulating products for building applications. Determination of long-term water absorption by immersion)

Sika Liquid Plastics’ Cem-topped Board should not be brought into direct contact with high temperature heat sources.  The maximum service temperature of Sika  Liquid Plastics’  Cem-topped Board is 75°C.

The design restraint of the Liquid Plastics’ Cem-topped Board when interlocked into an array is:

• Not interlocked into array Self weight
• Stretcher bond array Self weight x 2

The normal and recommended laying pattern for Liquid Plastics’ Cem-topped Board is the brick or stretcher bond pattern.
This method offers additional restraint values of two times self weight where the panels are locked into the array.  Panels with a free edge and not locked into the array should be  considered as self weight only.  The Sika Liquid Plastics’ Cem-topped Board should be laid so that the tongue and grooved edges fully interlock.  Where panels have to be cut the continuity of interlock should be maintained by the use of cross clipping.

Edge Detail Additional Restraint

Where the design requires additional ballast or mechanical restraint over and above the self weight values offered by the various methods of laying as described above, this is normally achieved by the use of 50mm concrete paving slabs loose laid over the panels at centres as appropriate to the design values.

Cutting

Use an angle grinder saw to cut through the cement topping.  Cutting of the extruded polystyrene insulation should be carried out using a fine toothed saw, or by scoring with a sharp knife and snapping the board over a straight edge and cutting the facing on the other side.  Ensure accurate trimming to achieve close butting joints and continuity of insulation.