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CasoLine MF

Concealed grid MF suspended ceiling system

CasoLine MF is a suspended ceiling system suitable for most internal drylining applications. The fully concealed grid and ceiling lining can be used in conjunction with Gyproc plasterboards and Gyptone and Rigitone boards to create a seamless, monolithic appearance.

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Tested specifications for your needs, and all related documentation, including BIM and dwg CAD files.

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  • Monolithic appearance
  • Suspension from concrete or timber floors and pulins
  • Acoustic hangers provide option of resilient suspension
  • Durable ceiling lining
  • Ventilation ducts and other services accommodated in plenum
  • Simple accommodation of access panels
  • Easy to create bulkheads and level change
  • Easily integrated with CasoLine GRID
  • Fully integrated access hatches


A wide range of residential, renovation and commercial applications.

Cavity barriers

Where cavity barriers are required, these can be formed using Gyproc FireLine or Glasroc F MULTIBOARD screw-fixed to a simple metal or timber frame. The framing should be fixed to the structure to avoid undue loading of the ceiling suspension grid or, alternatively, additional hangers should be incorporated to support the ceiling alongside the cavity barrier. Refer to WHITE BOOK section 10 – Cavity fire barriers.

Relative humidity

CasoLine MF ceilings lined with Gyproc, Gyptone, Rigitone or British Gypsum specialist boards are suitable for use under normal occupancy conditions. Buildings in which they are used should be dry, glazed and enclosed, with environmental conditions of no greater than 70% RH at 10°C to 20°C. For high humidity / high moisture conditions use Gyproc plasterboard MR variants or Glasroc F MULTIBOARD.

Vapour control

For areas other than where perforated Gyptone or Rigitone boards are used, a face layer of DUPLEX grade plasterboard or two coats of Gyproc Drywall Sealer applied to the face of the lining will provide water vapour control.

Acoustic performance

Gyptone and Rigitone boards are perforated and designed to provide sound absorption when used in conjunction with an airspace behind the ceiling. Increased levels of sound absorption can be achieved by including insulation over the back of the ceiling. Where sound insulation room-to-room is required, sound attenuation (Dncw) of 39 dB can be achieved by the inclusion of 100mm Isover Spacesaver Ready-Cut over the back of the ceiling. Alternatively, other design considerations should be adopted such as extending adjoining partitions into the plenum void or installing a plenum barrier.

Thermal performance

Isover insulation can be laid over the suspension grid to provide the required standard of thermal insulation. Contact the British Gypsum Drywall Academy for further guidance.

Ceiling lift

Changes to Building Regulations Approved Document L, airtightness requirements within dwellings, can lead to greater changes in air pressure when a door is opened. The ceiling is normally the lightest fixed element in the room, and therefore most likely to be affected by this change in pressure.

This can cause the ceiling to lift, which may create a noise. Whilst this noise can be annoying to the occupier, it has no detrimental effect on the performance of the ceiling.

The designer should consider incorporating a pressure release system to minimise the risk of ceiling lift. Where sufficient ‘pressure relief’ cannot be designed in, it is recommended that the Gypframe MF5 Ceiling Section and the Gypframe MF7 Primary Support Channel should be screw-fixed together using two Gyproc Wafer Head Jack-Point Screws at each intersection, particularly where non-perforated board linings are specified.

Suspension - Gyproc, British Gypsum specialist and Gyptone board linings

Fixing points for suspending the metal grid are required at 1200mm centres in each direction. Suitable fixing devices should be employed when fixing to the structure.

The ceiling grid can be suspended from a concrete soffit using Gypframe MF12 Soffit Cleats and Gypframe MF8 Strap Hanger, or alternatively, Gypframe GA1 Steel Angle. The latter provides a more robust suspension support, which restricts any flexing of the lining when pressure is applied from below. Gypframe GA1 Steel Angle is thus the preferred suspension option when a plaster finish is specified to Gyproc boards. If Gypframe GA1 Steel Angle is used, it is recommended that it is fixed to the soffit via Gypframe MF12 Soffit Cleats.

If fixing Gypframe GA1 Steel Angle direct to the soffit, the angle is cut and bent to fit. However, this will reduce the maximum loads that the grid is capable of supporting by 25%. Furthermore, fixing Gypframe GA1 Steel Angles direct is not suitable if the ceiling is likely to deflect due to varying pressures and is not suitable for fixing to a sloping substrate.

Gypframe Acoustic Hangers can be used to suspend the grid from timber joists to maximise the degree of acoustic isolation (see WHITE BOOK Construction details – 7). In a comparative test a 3 dB improvement in airborne sound insulation and a 6 dB improvement in impact sound insulation were achieved. See Table 7, Construction details 2 and 4, relating to double layer Gyproc SoundBloc linings. With concrete floors the high mass of the construction means that high levels of acoustic performance can be achieved when the CasoLine MF ceiling is suspended by conventional means, i.e. Gypframe MF8 Strap Hangers or Gypframe GA1 Steel Angle.

Suspension - Rigitone board linings

Gypframe MF7 Primary Support Channels are fixed at 1000mm centres. Fixing points to the structure for the Gypframe MF7 Primary Support Channels are required at 900mm centres. In addition to this, the Gypframe MF5 Ceiling Section should be installed at nominal 330mm centres.

Partition to suspended ceiling junction

In situations where a GypWall metal stud partition passes through a CasoLine MF ceiling, which is to both sides of the partition and appropriately fixed to both this partition and perimeter partitions / walls, consideration can be given to the lateral restraint provided by the ceiling when developing the partition specification.

The relevant maximum height is the greater of the floor to CasoLine MF ceiling or ceiling to structural soffit height. Care should be taken during installation of tall partitions so as to not adversely affect their performance. Contact the British Gypsum Drywall Academy for further guidance.

Where a GypWall metal stud partition is fixed to the framework of a CasoLine MF ceiling, in accordance with British Gypsum’s installation instructions, the permissible maximum height is equal to that of where it is fixed direct to a structural soffit of the same height.

Imposed loads

WHITE BOOK Tables 10, 11 and 12 provide loading data for the suspension grid for Gyproc, British Gypsum specialist, Gyptone and Rigitone boards respectively. Maximum loads will be reduced by 25% when Gypframe FEA1 Steel Angle is fixed directly to the soffit (modified loads are shown in brackets).


The plenum can be used to route all service requirements including ducting, pipework, electrical cables and conduit. Where light fittings, access panels and similar components are incorporated as part of the design requirements, consideration must be given to maintaining the integrity of the ceiling to meet fire resistance and sound insulation requirements.


Fixings to the system should always be made into the metal grid or to supplementary framing. Some adjustment of the primary grid may be required to support particularly heavy loads, see WHITE BOOK Tables 10, 11 and 12. Where loads outside this range are anticipated, independent suspension should be provided from the structure.

Control joints

Gyproc Control Joints may be required in the ceiling to relieve stresses induced by expansion and contraction of the structure. It is recommended that they coincide with movement joints within the surrounding structure.

Rigitone expansion joints

Rigitone boards should be cut 10mm short of the perimeter wall and should not be fixed to the perimeter channel, see WHITE BOOK Construction details – 12 - 13.

Board finish

Additional care and attention should be exercised when jointing Rigitone boards so as not to fill the perforations and impair the acoustic performance of the finished ceiling. Refer to WHITE BOOK section 13 – Finishing systems and decorative effects.

Gyptone boards with ACTIVair

Though we don’t notice them, impurities, such as volatile organic compounds (VOCs), are often present in the air we breathe – emitted from furniture, carpets and building materials. Long-term exposure to these can potentially cause health problems and reduce general wellbeing.

Though we don’t notice them, impurities, such as volatile organic compounds (VOCs), are often present in the air we breathe – emitted from furniture, carpets and building materials. Long-term exposure to these can potentially cause health problems and reduce general wellbeing.

Clean air, on the other hand, can speed up patient recovery in hospitals, reduce absence at work, and increase pupils’ concentration at school. ACTIVair is our latest technology designed specifically to convert VOC emissions into non-harmful inert compounds, making the air around you up to 70% cleaner. This clever technology continues to work for over 50 years, and whilst alternative solutions absorb VOCs, they don’t decompose them like ACTIVair, risking re-emission at a later date. Refer to WHITE BOOK section 14 – Products, ceilings.

  • Sound absorption: 0.25 - 0.70 (aw)
  • Sound insulation airbourne: 56 - 66 (Rw dB)
  • Sound insulation impact: 68 - 50 (Lnw dB)
  • Fire resistance: 30 - 120 (mins)

Are timber inserts required to metal stud partitions?

Not necessarily but they could be considered to provide support for fixtures, etc.

How to...install the CasoLine MF system