If you are using a steel subframe, a minimum 50 mm fixing face and a 0.6 mm gauge stud must be used, with associated head and floor track to suit. If you are using timber for the subframe, you will need (75 mm x 50 mm) P.S.E. well seasoned timber for both the vertical studwork and the head and floor track. An 89 mm x 38 mm studs may be used, but only with the adhesive or Tapered edge jointing system.

For full installation details please see step by step guide to partitions

Either: score using a Fermacell board knife, then snap off (fig.1). Scored and snapped edges can be smoothed off using a surform plane.

Or: cut using a hand or electric circular saw (dust extraction may be required).

Fix boards to timber or DIN standard metal studs at 600 mm centres. Ensure that Fermacell screws are placed 250 mm apart but not within 10 mm of the edge of the board or 50 mm from the corners (fig.2). They may also be fixed to timber studs using pneumatically fired staples or nails.

Ensure a gap of 5 mm is left at junctions with other adjoining surfaces – filled later with a flexible sealant. All joints should be staggered by at least 200 mm, both horizontally and vertically.

Square edge boards can be jointed in two ways:

Joint Filler

If you score and snap the boards leave a 5-7 mm gap between them. Fill the gap with Fermacell Joint Filler (fig.3). Horizontal joints will need to be backed with an offcut of Fermacell fixed through the board. This method of jointing allows you to use up your offcuts.

Jointstik

If you cut the boards with an electric saw the edges can be bonded with Fermacell Jointstik glue (fig.4). Position the next board into place leaving a gap of no less than 1 mm, allow the Jointstik to squeeze out and leave it to cure.

Joint Filler and Joint Tape for tapered edge boards

Tapered edge boards are dry butt-jointed and filled using Fermacell Joint Filler and Joint Tape (fig.5).

Surfaces should be dry and free of stains and dirt. Any damage to be filled with Fermacell Joint Filler or Fine Surface Treatment (FST) and allowed to dry. Fill the screw heads with Fermacell Joint Filler (fig.6).

Apply Fermacell FST to the board surface direct from the tub using a trowel or a 250 mm FST spatula (fig.7).

Work on an area approximately 1-1.5 m² at a time. Apply the FST liberally then remove excess FST with a trowel or the FST spatula. The removed FST is returned to the bucket. The finished thickness

FST will dry within 45 minutes, and is now ready for painting. After filling the screw heads (fig.6) wallpaper can be applied directly to Fermacell without the need for FST (fig.8).

Corners: Fermacell does not need corner beads, simply align the board flush with the factory machined edges together, bond with Jointstik and finish with FST.

Jointstik is used for gluing square edge boards together. Each cartridge will cover 20 linear meters of joint using a 3 mm bead. This equates to approximately 8 boards.

Fermacell Jointstik adhesive is applied to the edge of the board in a continuous 3 mm bead prior to fixing the next board.

Because the adhesive expands on contact with air, the bead should be applied to the edge of square edge boards and not the ‘V’ between the tapers of Tapered edge boards.

If the bead is applied incorrectly, excess Jointstik may be trapped between board and subframe causing subsequent lipping.

Once Jointstik is applied the next board is then fitted to the subframe, spreading the adhesive across the face of the board edge and ensuring a tight fit of less than 1 mm. Allow the adhesive to harden fully before attempting to remove any excess (typically 8-12 hours). Once hardened, the excess can be struck off with a decorator's scraper. There is no requirement for noggins behind these joints. The final gap between boards with Jointstik should be less than 1 mm.

Any greater than this may result in weaker joints. If Jointstik has been for a long period it may be hard to remove, a Surform or any similar tool may be used to remove it. The joint and screw heads should then be filled with Fermacell Joint Filler. All joints above 2500 mm partition height must be jointed using Jointstik or reinforced with noggins. Horizontal joints are jointed in the same manner as vertical Joints.

A hard filler used for jointing Tapered edge boards, jointing the gaps between cut edges and for filling screw heads. As well as an alternative to Jointstik when using square edge boards.

If using Tapered edge boards, jointing tape will be required. We recommend a paper tape rather than a self adhesive fibre tape as this gives a stronger joint. When using Fermacell Joint Filler for Tapered edge boards, allow 1 kg per 4 meters of joint length, and 1 kg per 7–8 meters of joint length for jointing off cuts.

For use in sealing the gap between boards and other material surfaces such as walls, floors and ceilings. Typically, this should be where any building movement is expected on internal corners or abutments. The edges of the boards must be primed prior to application, and the sealant should be fire or acoustic rated as required.