How to Hang Curtains and Blinds Straight on Plasterboard

Photo by GLOBALDSIO IT SOLUTION on Unsplash (https://unsplash.com/photos/1771039621892-6487a5c5602f)

By Mick — lead handyman, Newcastle NSW.

I’ve hung close to two thousand curtain rods and blinds over twenty-five years on the tools, and I can tell you right now: the laser level you bought at Bunnings last weekend is lying to you. Not because it’s broken. Because the ceiling above it is wonky. Aussie houses — even the brand-new house-and-land jobs out at Cameron Park — almost never have a level ceiling. The cornice runs uphill, the bulkhead drops 4 mm over a metre, and your eye reads the whole wall against that ceiling line. So you set your laser perfectly level, mount the rod, and the curtains look crooked anyway because they’re parallel to gravity and the cornice isn’t.

The fix is what I call the “two pencil dots and a string” method. It takes ninety seconds, costs nothing, and makes the rod look right against whatever the ceiling is actually doing. Ninety per cent of the YouTube blokes are teaching the wrong technique because they’re working in plasterboard offices with proper square ceilings. Aussie homes are different.

The other reason this article exists: most blockout curtain installs I get called back to fix were never going to last. Whoever did the original job whacked a generic plastic anchor in the Gyprock, hung 8 kg of fabric off it, and the anchor pulled clean out within a year — bringing a 50 mm crater of plasterboard with it. We’re going to fix that for good.

What you’ll need

Stanley FatMax 5 m tape measure
HB pencil (sharp — not the chewed stub in the drawer)
Roll of mason’s line or any string about 1.5 m long
Stud finder (Stanley S100 or a Bosch GMS 120 if you want to spend a bit)
Cordless drill with PH2 bit and a 3 mm pilot drill
Spirit level — 600 mm minimum, the little 200 mm torpedo levels are useless for curtain rods
Hangman snap-toggle anchors (rated 22 kg into Gyprock) OR Toggler SnapSkru SP for lighter loads
Curtain rod brackets and the screws they came with — bin them and use 35 mm × 8g countersunk timber screws into studs where you can
Stepladder, not a kitchen chair

Run the stud finder horizontally along the wall about 150 mm above the window — mark every stud edge before you commit to bracket positions.

Step 1: Decide the height before you touch the wall

Standard rule for curtains: 150 mm above the window architrave, or halfway between the architrave and the cornice if that gap is less than 300 mm. For floor-to-ceiling drama (which is what most of my clients want now), go right up to within 50 mm of the cornice. Whatever you choose, write it down — left side height and right side height — because you’re going to forget by the time you’re up the ladder.

Step 2: Find the studs first, position the rod second

This is where 99% of installs go wrong. People decide where the brackets go, then drill, then discover they’ve missed the stud by 40 mm and now they’re committed. Run the stud finder along the full width of the window plus 200 mm either side. Mark every stud edge with a pencil tick. Aussie stud spacing is usually 450 mm or 600 mm centres — but in older Newcastle weatherboard homes I’ve seen everything from 380 to 720, so don’t assume.

Step 3: The two pencil dots

Mark your bracket centre on the left at the height you decided. Now measure across to the right side and put a pencil dot at the same height on the right. Don’t level it yet. Just match the height off the floor — measure from the floor on both sides, not from the cornice.

Step 4: The string trick

Stretch your mason’s line tight between the two pencil dots. Now stand back three metres and look. If the string runs parallel to the top of the architrave (and roughly parallel to the cornice), you’re done — that’s your line. If it looks crooked because the floor slopes, split the difference: nudge one dot up or down 2–3 mm until the string looks right against both the architrave and the cornice. Your eye is the final judge, not the spirit level. The string IS the level for this job because it averages out the room’s wonkiness.

Step 5: Transfer to bracket positions

With the string still in place, mark the bracket screw positions. For a standard double rod bracket you’ve got two or three screw holes per bracket. Your goal: at least one screw per bracket lands in a stud. If both can hit the stud, even better. If neither can — because your window is positioned between studs — that’s where the Hangman toggles come in (Step 7).

Step 6: Pilot drill (don’t skip this)

3 mm pilot hole, 30 mm deep, into every screw position that’s going into a stud. Pilot holes stop the screw from snaking sideways through the soft pine and pulling the bracket off-true. For Gyprock-only positions where you’ll use toggles, drill the size the toggle packet specifies — Hangman snap-toggles want 13 mm, Togglers want 8 mm.

Step 7: Toggles for the no-stud positions

Here’s where the Aussie gotcha bites the US-tutorial crowd. American drywall is denser and 12.7 mm thick. Aussie Gyprock is 10 mm in most homes (13 mm in wet areas) and softer. A US “drywall anchor” rated 5 kg holds about 2 kg in Gyprock before the paper tears. For any blockout curtain over 4 kg total weight, use a Hangman snap-toggle (rated 22 kg in 10 mm Gyprock) or a Toggler SnapSkru SP. Avoid the brittle plastic expansion plugs — they’re for picture frames, not curtains.

Step 8: Mount the brackets and check with the long level

Drive the screws to firm — not gorilla-tight. With clip-on brackets you’ll feel them seat. Now lay your 600 mm spirit level across the tops of both brackets. It probably won’t read dead level, and that’s fine — you levelled to the room, not to gravity. Hang the rod and step back. If it looks straight against the architrave and the cornice, the job is right.

Step 9: Hang and adjust the curtains

Put the curtains up before you finish tightening everything. Sometimes the weight pulls the rod down 1–2 mm at a bracket and you’ll want to nudge a screw. Better to find that now than in six months when one side has sagged.

Step 10: The 24-hour test

I always tell clients: open and close the curtains hard ten times the next day. If the brackets feel tight and the rod hasn’t shifted, you’re done. If anything has moved, it’s a stud miss or an under-spec’d anchor — fix it now before the kids start swinging on the curtains.

Common things that go wrong

A few patterns I’ve seen on call-outs over the years, in case you hit them:

The brass screw that snaps off in the bracket. The cheap brass screws that come in cheap curtain rod kits will shear at the head if you torque them past about 1.5 Nm. Use the lowest clutch setting on your cordless (most have a clutch with positions 1–20; start at 5 and only go up if needed). Or run them in by hand for the last few turns.
Bracket spins free under load. You missed the stud and the toggle never deployed inside the cavity. Pull the bracket, look at the toggle — if the toggle didn’t open behind the plasterboard, the hole was too small or you didn’t push the toggle through. Drill the hole to the toggle’s spec size and re-fit.
Curtain rod sags in the middle. Long rods (over 2 m) need a centre support bracket. Don’t rely on two end brackets for a 3 m rod — the sag becomes obvious within a week and the curtains never look right.
Eyelet curtains binding on the rod. The eyelet inner diameter needs to be at least 5 mm bigger than the rod diameter or they snag every time you draw them. If you bought 38 mm rod and 38 mm eyelets, that’s why they stick.

The Mick rule

Level the rod to the room, not to gravity. The string between two equal-height pencil dots beats a laser level every time in an Aussie house, because the human eye reads the rod against the cornice and architrave — not against an invisible horizontal plane. And if you can’t hit a stud, spend the extra two bucks on a Hangman snap-toggle. Generic plastic plugs in Gyprock are the reason I get callbacks.

Got a curtain or blind install that’s gone sideways? Send us a write-up.