Fixing GIB to Ceilings

Table 1: Zone Selector

GIB® Dry Zone®		Fire rated GIB Aqualine®
Superior protection from steam and moisture damage	Bathroom, ensuite, toilet, kitchen and laundry	Contains special wax polymers to help prevent water absorption
GIB Quiet Zone®		GIB Noiseline®
Using two layers helps reduce the noise entering through walls and ceiling	Bedrooms, study and TV room	Stronger, higher density and more rigid core. Much tougher than standard plasterboard
GIB Toughzone®		GIB Toughline®
Improved durability and greater resistance to damage	Stairway, hall, rumpus room, garage and children’s bedroom	Twice as tough as standard plasterboard due to high density core and fibreglass mesh
GIB Feature Zone®		GIB Ultraline®
Superior smoother looking ceilings and walls	Ceilings and walls in feature areas such as lounge and dining areas	Finer, smoother, resin coated face paper
GIB FireGuard Zone®		GIB Fyreline®
Added protection for expensive assets in the home	Kitchens and other “at risk” areas	High density core for up to 4 hours extra protection in the event of fire

Many of these can be combined in the same area or room. For more information about this contact the GIB® Helpline on 0800 100 442.

Handy Hints

In older houses the moisture content will probably be OK. If there is any doubt have the moisture checked by a professional.

PREPARING THE SUBSTRATE

Preparation is paramount to achieving a good finish. Take the time to ensure that the surface is as flat and straight as possible before applying plasterboard.
1. Remove any nails, old glue or other fixings that are protruding from the timber.
2. Using an 1800mm straight edge, check the flatness of the ceiling. There should be no deviations in the framing greater than 2-3mm from the straight edge.
3. Plane any high areas flat or straighten any misaligned battens.
4. Check the timber is dry. The moisture content of the timber should be less than 15%. Timber with a moisture content outside these limits is prone to movement causing problems with joint distortion.

HANDLING & STORAGE

Handling

Plasterboard is a finishing material and as such should be treated with care. Do not walk or sit on stacks of plasterboard. Carry plasterboard on its edge. Apart from being easier to carry, sheets are less likely to crack or break.

When taking sheets from a stack, avoid dragging a sheet across the one below it as this can damage the face paper. Consider using a mechanical board lifter when fixing plasterboard sheets to a ceiling. These can be hired from most hire outlets or specialist stores.

Storage

The sheets should be stacked in neat flat stacks, clear of the floor, to avoid damage to edges, ends and surfaces. Stacks of plasterboard should be limited to stacks of 20 sheets on non-concrete floors to minimize the risk of structural damage due to point loading. If plasterboard is being stored on new concrete floors the plasterboard should be elevated or stored on a piece of waterproof polythene sheet to prevent it from picking up moisture from the concrete.


	Handy Hints Plasterboard sheets are heavy and may bend or snap under their own weight. Handle sheets carefully and make sure they are properly supported prior to fixing.

CUTTING & ATTACHING

Cutting

1. Place the sheet with the light-coloured face paper side up. Measure and mark the sheet to the size desired.
2. Line a straight edge up with the marks and hold firmly against the sheet. Draw a pencil line as a guide for scoring. Score through the paper and lightly into the core using a craft knife. (Extreme care should be taken when using sharp tools such as these)
3. To break the sheet core, securely grasp the board edges on both sides of the score line and snap the board with a quick, firm movement. Alternatively, break the sheet over the end of the working surface or a length of timber.
4. Complete the cut by running the knife through the back paper of the sheet.

Cut Outs

For openings such as a light fitting use the following method. DO NOT use a hammer to create the hole.
1. Measure from where the side of the sheet will be located to the near and far sides of the light fitting.
2. Measure from the top or bottom edge of where the sheet will be located to the top and bottom of the light fitting.
3. Trace the outline of the light fitting at the appropriate position on the sheet.
4. Cut with a keyhole saw.


	Handy Hints Do not fix nails or screws through or closer than 200mm from adhesive as this can cause the nails or screws to ‘pop’ as the glue dries and shrinks.

Attaching

The best practise for fixing plasterboard involves the use of screws and glue. Screws are used around the perimeter of the sheet and glue should be used in the other areas that contact battens.

Planning the layout

Use sheets that are the full length of the room, if possible, so that no end joints are formed. If ‘end’ joints must be formed then these should be staggered.

Battens should be fixed at right angles to the trusses or joists. Where trusses or joists change direction within a room, battens should be fixed in one direction only. This may require additional nogs or dwangs between trusses. Plasterboard sheets should be fixed at right angles to the battens.

Battens should be placed at a maximum of 600mm centres when using 13mm plasterboard. If 10mm plasterboard is used, battens should be spaced at a maximum of 450mm centres. Back-blocking will be required on the edge (longitudinal) joints where the room is wider than six sheets (7.2m) on metal battens and four sheets (4.8m) on timber battens.


	Handy Hints Use an electric screwdriver equipped with an adjustable depth control head and Phillips bit. If a screw is overdriven and the paper and/or core of the plasterboard is damaged, insert a second screw approximately 50mm from the first and then remove the first screw. Repair damaged area by filling.

Installing plasterboard

Screwing is the preferred method of fixing. Nails must NOT be used when fixing plasterboard to metal battens.

1. Apply GIBFix® All Bond glue daubs to the battens at 200mm, 400mm, 800mm and 1000mm centres starting from the wall/ceiling junction. Do not apply glue to the battens closest to the wall or the edge of the sheet.
2. Lift the sheet into position and support using the T-braces by wedging these between the floor and the ceiling.
3. Starting from the centre of the sheet and working towards the outside, screw the sheet in place using 32mm x 8g GIB® Grabber® screws.
4. Fix the centre of the sheet to each batten and to either edge of the sheet.
5. Fix each end of the sheet at 200mm centres.
6. Fix the remainder of the sheets in the same fashion, fitting each sheet to the edge of the previous sheet.


	Handy Hint Because sheets are difficult to manoeuvre above your head, it is best to enlist the help of one or two extra people. Alternatively consider using a mechanical board lifter available from most good hire companies.

FIXING PLASTERBOARD

Back-blocking

If end joints in a room cannot be avoided then back-blocking will need to be done. Back-blocking is a practise that strengthens the joints between plasterboard sheets by creating an artificial taper at the ends of sheets. It consists of laminating strips of plasterboard to the back surface of GIB® sheets directly behind the joints using GIB Cove® Adhesive. Due to its flexibility do not use GIBFix or any other panel adhesive for back-blocking. For back-blocking, butt joints in ceilings with easy access - this can be done after the ceiling has been installed.
1. Place a 1-2mm packer along the butt joint to bend the ends of the plasterboard back.
2. Apply three temporary battens on either side of the joint with temporary fixings to hold the packer in place.
3. Apply a piece of plasterboard that fits between the battens and is 400mm wide to the back of the joint using GIB Cove® Adhesive.
4. Once the plaster has set, remove the fixings from the temporary battens.

Making your own T-braces

1. Measure and cut two pieces of 100 x 50mm timber that are 15mm longer than the floor-to-ceiling height.
2. Nail a 1m long section of 100 x 25mm timber to the top of the long boards.
3. Wedge the T-braces between the floor and sheet, taking care not to damage the surface of the sheet.

Jointing & decorating

Jointing (stopping) plasterboard is a skill that requires some practise. Because of this, you should consider the services of an experienced tradesman. Not only will they achieve a better finish, which is important when painting walls, but they will finish the work more quickly and with less fuss.

Should you wish to try this yourself then take a look at the Joint GIB® Plasterboard How to Guide for more tips and information. Also in this guide is some further information on decorating plasterboard. Paint systems should always be applied in accordance with the paint manufacturer’s instructions.

NOTE: Whilst the advice and recommendations contained in this brochure have been produced with proper care, they are offered only with the object of assisting those interested in or involved with the fixing of plasterboard. Winstone Wallboards Ltd and BRANZ do not accept responsibility for the advice, recommendations, etc., contained herein.