Plasterboard fixing and jointing defects at handover: prevention on the tools

Ask a certifier or a new owner what they found at handover and the list usually reads the same: a hairline crack running out from a door head, a line of fastener heads showing through the paint, a joint that is visible under raking light, a corner that is not straight. None of those are board faults. They are fixing and jointing outcomes.

That distinction matters commercially. If the defect is a lining selection problem, the fix is a different product and a variation. If it is a fixing or jointing problem, the fix is rework on your programme, in your cost, at the worst possible point in the job — after the painter has finished and often after the owner has moved in.

This article deals with the second category. It covers how sheets are set out, fixed and jointed, and what to look at before you let the painter near the wall.

Why fixing and jointing, not lining selection, drives most handover defects

Plasterboard is a rigid sheet fixed to a frame that is not perfectly rigid. The frame moves with load, with moisture change in timber, with thermal movement, and with the settlement that every new building undergoes. The lining has to accommodate that movement without cracking.

What lets it do that is the fixing pattern, the sheet layout and the jointing. Fixings hold the sheet against the frame at controlled centres so load is transferred evenly. Joints are taped and built out in coats so the joint is wider than the movement it has to absorb. When either is done badly, the lining becomes the place where frame movement shows up.

The PointCPD article on building defect liability and insurance sets out why this matters beyond the handover walk. A cracking defect that appears inside the statutory period becomes a claim against you, not against the subbie who hung the sheets, unless your subcontract paperwork and your supervision records put the obligation where it belongs.

The fixing pattern is a load path, not a spacing rule

Fixing centres exist because the sheet has to be held against the frame at close enough intervals that it cannot bow, drum or work loose. The correct centres depend on the sheet thickness, the framing type and the stud spacing, and they are set out by the manufacturer. Where a project specification is silent, the manufacturer’s installation instructions are the document to check.

Two things go wrong most often. The first is that fasteners are placed too far apart in the field because it is faster. The sheet then has unsupported spans between fixings that move under hand pressure and show as a shadow line under paint. The second is that fasteners are placed too close to sheet edges, which tears the paper and destroys the holding capacity of the fixing.

Fasteners must finish flush with the paper face. A head that sits proud will be sanded over and will show through the finish. A head that has been driven through the paper has nothing to hold against and will pop. Both are visible to a trained eye before jointing starts, which is the cheapest possible time to deal with them.

Sheet layout decides where the cracks will appear

Where a sheet ends determines where a joint is, and where a joint is determines where a crack can open. Sheet ends should land on framing, not in the span between studs. Cut edges should be positioned where they are least visible, typically into corners and against door and window reveals rather than in the middle of a long wall.

Staggering sheet joints between adjacent courses and between opposite faces of a wall matters as well. If joints line up vertically through a wall, the wall has a continuous line of weakness from floor to ceiling and the crack, when it comes, runs the full height.

Framing tolerances feed directly into this. A stud that is out of line, a nogging that is set back, or a top plate that is not straight will all show in the finished lining regardless of how good the jointing is. Check the frame before sheets go on, not after.

Jointing is a drying process, not a filling process

The single most common cause of joint cracking that appears after painting is compound that was not dry when the next coat went on. Jointing compound shrinks as it cures. If a second or third coat is applied over compound that is still wet underneath, the trapped moisture escapes later, the surface shrinks unevenly, and a hairline crack opens along the joint.

The crack typically appears days or weeks after the painter has finished, which is why it turns up on a handover walk or in the first month of occupancy rather than during construction. By then the painter has been paid and left, and the cost of the fix — re-taping, re-coating and repainting a wall in an occupied building — sits with whoever is still on site.

Each coat has to be allowed to dry through before the next is applied. On a programme with a tight internal fit-out, that is the stage most often compressed, and it is the one where compression is least recoverable.

The jointing stages and what each one is for

Each stage of jointing has a job. Tape embed bonds the tape to the board face. Subsequent coats build the joint out so the compound feathers across a width greater than the joint itself, which is what gives the joint its ability to absorb small movements without cracking. The final coat brings the joint level with the board face across the full feathered width.

Corner treatment follows the same logic. Internal corners take tape bedded into compound on both faces. External corners take a bead or a taped corner, fixed so the corner is straight over its full height. A corner that is not straight will be visible from every angle in the room, in a way a flat wall defect is not.

Sand and finish without cutting into the paper

Sanding removes ridges and tool marks. It should not cut through the compound into the board’s paper face, because the paper is what gives the joint its surface integrity. A sanded-through joint looks fine under normal light and fails under raking light or after painting, because the paint absorbs differently into the exposed core.

Where a joint has been sanded through, the correct fix is to re-coat the joint, not to spot-prime it and move on.

Wet area linings are a jointing problem as well as a substrate problem

Wet areas combine the usual lining issues with a substrate that is being asked to do more. Linings in wet areas must be fixed in accordance with the requirements for that area, and the jointing and finishing must be compatible with what goes over the top, whether that is a waterproof membrane, tiling or a painted finish.

Movement joints in the tiled finish and in the lining need to work together. Where a movement joint is required in the tiling, the lining behind it needs to accommodate the same movement, or the tile joint becomes the place where the lining crack telegraphs through. The related article on wet-area tile lippage and movement joints deals with the tiling side of that interface; the lining side is a fixing and jointing decision made weeks earlier.

What the defect data says about lining failures

The Building Commission NSW Building Defects Library is a public record of defect types that have been identified in NSW buildings, and internal lining defects appear in it alongside waterproofing, structural and fire safety issues. The Commission’s research on serious building defects in NSW strata communities examines how these defects present across strata buildings and what they cost to rectify.

The practical point for a builder is that a lining defect is not a cosmetic nuisance. It is a recorded defect category that a certifier, an owners corporation or a subsequent purchaser can point to, and it is one of the easier categories to avoid with supervision at the right stage.

If you want to understand how defect liability periods and rectification obligations operate around these categories, the explanation of the NSW defect liability period sets out the framework.

Site conditions that turn a good job into a cracking job

Plasterboard and jointing compound are both moisture-sensitive. If sheets are delivered and stored on site before the roof is on or before the building is closed up, they take on moisture. When the building dries out, the sheets shrink and the joints move.

The same applies to jointing compound. Compound applied in a cold, damp building dries slowly and unevenly, which is the practical version of the drying problem described above. Ventilation and, where necessary, temporary heating during jointing are quality controls, not comforts.

Programme sequencing matters too. Jointing should not be run before the building is weathertight, and wet trades that introduce large amounts of moisture into the space — screeds, tiling, rendering — should not be running in the same area at the same time as jointing where it can be avoided.

Worked example: a builder in western Sydney

A builder in western Sydney is completing a two-storey dwelling for a private client. The internal fit-out is running behind after a wet winter. To hold the handover date, the jointing subbie is asked to compress the jointing programme, and the painter is booked to start the day after the final coat goes on.

At handover, the client’s inspector walks the house with a torch held low against the wall. Three things are picked up. A hairline crack runs from the corner of a bedroom door head across the wall. A line of fastener heads is visible along a stud line in the living room. A joint in the hallway is visible under raking light but not under normal light.

The builder inspects each one and traces it back. The door head crack is a joint that was coated before the previous coat was dry, compounded by the painter starting early. The fastener line is a series of fixings that were driven through the paper and not reset; they held long enough to be jointed over and then popped as the frame settled. The hallway joint is a sanded-through joint where the paper face was cut into and then spot-primed.

None of the three is a board fault. All three are fixing and jointing outcomes, and all three were visible or preventable before the painter started. The rectification involves re-taping and re-coating the door head and hallway joint, resetting and re-filling the popped fasteners, and repainting the affected walls in an occupied house, at the builder’s cost, after practical completion.

The lesson is not that the subbie was bad. It is that the compressed programme removed the drying time that the jointing process depends on, and there was no inspection step between jointing and painting to catch what the compression produced.

Supervising the work so the defects do not reach handover

The control point is the gap between jointing and painting. Once the painter is on the wall, every lining defect becomes a paint and rework problem. Before that, most of them are a ten-minute fix.

Walk the lining with the jointing subbie before the painter starts. Use raking light from a low angle, which is how a defect inspector will look at it. Press along the fastener lines by hand. Check corners over their full height, and check sheet ends at door heads and window reveals, which is where cracking shows first.

Ask the subbie directly whether each coat was dry before the next went on. If the answer is uncertain, treat the joint as a risk and inspect it more closely rather than accepting it.

Record what you find and what you decide, including anything you are choosing not to fix and why. If a defect does surface after handover, that record is what separates a supervised decision from an unsupervised omission.

Safe work considerations during lining and jointing

Lining work involves sheet handling, overhead fixing, working at height and dust. The Safe Work Australia code of practice for construction work sets out the risk management duties that apply to this kind of work on a construction site, including the controls for working at height and for hazardous manual tasks.

Older buildings being refurbished may have asbestos-containing sheet or jointing compound in the existing lining. Where that is a possibility, the Safe Work Australia code of practice for the safe removal of asbestos sets out how removal is to be managed. Do not assume that a lining is asbestos-free because it looks like modern plasterboard.

If you are working through how these duties and the defect obligations fit into your CPD, the guide to how NSW builder CPD works explains the categories and what counts.

The commercial case for fixing it before the painter arrives

A lining defect that reaches handover costs you the rework, the repaint, the access to an occupied building, and the time spent managing the client’s response. A lining defect caught before painting costs you a tube of compound and an hour of the subbie’s time.

That ratio is the whole argument for supervision at the jointing stage. It is also the argument for protecting the drying time in the programme, because the drying time is what the jointing process is actually made of.

If you want to build the inspection of this stage into your own practice, the PointCPD course catalogue covers defect prevention and quality supervision for NSW builders.

Questions builders ask

• Defects
• Linings
• Quality

Published 10 September 2026. General information for builders, not legal, financial or engineering advice for a specific job. Check current requirements with the relevant regulator or standard before relying on them.