Why will my roller blind not roll up properly?
Diagnosing a roller blind that hangs crooked, jams, tracks sideways off the tube or will not retract, and the levelling error behind most of it.
- Difficulty
- beginner
- Time
- 30 min
- Read
- 5 min
Short answer
Most roller blind faults come from the tube not being level: a fabric that tracks sideways, a blind that hangs at an angle, one that jams at one end. Check the brackets with a spirit level first. Then check the fabric is rolling off the correct side of the tube, that the side-winder chain has not jumped its sprocket, and on a spring blind, that it still has tension.
A roller blind is a fabric wound onto a tube, and it stays where it is put purely because it is wound straight. That makes it the blind type most sensitive to being fitted a millimetre out of level, and it is why the same handful of symptoms come up again and again with the same underlying cause.
What you'll need
- Spirit level, ideally a small one that sits on the tube
- Screwdriver
- Masking tape, for correcting tracking
- Replacement chain or a side-winder mechanism (optional)
- Fabric scissors and a straight edge, for trimming (optional)
Step by step
- Take the blind out and check the brackets with a level.Lift the tube out of its brackets and lay a level across both. A millimetre or two of difference across a 1m window is enough to make the fabric walk sideways as it rolls. This is the cause of most roller blind complaints.
- Check which way the fabric comes off the tube.Fabric can hang from the back of the roll or the front. If it is fitted the wrong way round for its bracket type, it will foul the reveal or the window frame and jam. Reverse it and see.
- Correct sideways tracking with tape on the tube.If the fabric consistently walks towards one end, unroll it fully and stick a strip of masking tape around the tube at the opposite end, under the fabric. The slightly larger diameter there pulls the fabric back. One or two layers is usually enough; add gradually.
- Check the chain has not jumped its sprocket.On a side-winder blind, take the chain off the mechanism, check the loop is not twisted, and refit it fully into the sprocket teeth. A chain that skips or slips is almost always partly off.
- Look at the clutch mechanism for debris.Dust, a stray thread or a broken chain link jams the clutch. Pull the mechanism out of its bracket, clear it, and refit dry — no oil, which collects more dust.
- Re-tension a spring blind.On a spring-loaded blind, pull it fully down, lift the tube out of the brackets, roll the fabric up by hand two or three turns, and refit. That adds tension. If it now snaps up too fast, unroll a turn and try again.
- Check the blind is not simply too wide for its reveal.A blind rubbing against the reveal at one edge drags and rolls unevenly. There should be a few millimetres of clearance each side on an inside mount.
- Check the bottom bar is square and its pocket is straight.A bottom bar that has slipped in its pocket, or a fabric hem sewn slightly out of true, makes the blind hang crooked no matter how level the tube is. Slide the bar out and re-seat it.
- Look at the fabric edge if it is a cut-down blind.Blinds trimmed to width at home are frequently cut a fraction out of square, which guarantees tracking. Re-trim against a long straight edge with the fabric fully unrolled and flat.
- Fit any looped chain's safety device before finishing.A looped side chain must be secured to the wall with the cleat or tensioner supplied. This is not optional — see the blind cord safety guide.
Tips
- Roll a roller blind up fully and leave it for a day after any adjustment. Fabric relaxes, and a fault that looks fixed at the time sometimes reappears.
- Never force a jammed blind by pulling harder. The clutches are plastic and they break, and a broken clutch is a new mechanism rather than an adjustment.
- If a blind has always tracked since the day it went up, suspect the brackets. If it started recently, suspect the mechanism or the fabric.
Common mistakes
- Adjusting the fabric before checking the brackets are level — A tube that is not level will keep pulling the fabric to one side whatever you do to the fabric.
- Oiling the clutch mechanism — It collects dust and gums up worse than before. Clean it dry.
- Trimming a blind to width freehand — A cut a millimetre out of square across the width makes the blind track sideways permanently. Use a long straight edge on a flat floor.
- Pulling harder on a chain that is slipping — The clutch teeth are plastic and they shear. Take the chain off and reseat it instead.
If it doesn't work
The fabric walks to one side as it rolls up
Cause: Tube not level, or fabric cut out of square — Fix: Level the brackets first. Then correct with masking tape wrapped round the tube at the opposite end, adding a layer at a time.
The blind hangs at an angle when down
Cause: Brackets at different heights, or the bottom bar has slipped in its pocket — Fix: Level the brackets and reseat the bottom bar.
The chain slips and the blind drops
Cause: Chain off the sprocket, worn clutch, or the blind is heavier than the mechanism is rated for — Fix: Reseat the chain. If the clutch is worn, replacement mechanisms are sold separately and fit most standard tubes.
A spring blind will not stay up
Cause: Lost spring tension — Fix: Pull it fully down, lift out, hand-roll two or three turns, refit. Repeat once more if needed.
The blind jams against the reveal
Cause: Too wide, or rolling off the wrong side of the tube — Fix: Reverse the roll direction, or trim the blind — squarely — to leave a few millimetres clearance each side.
Questions people ask
Why does my roller blind roll up crooked?
Almost always because the tube is not level. Take the blind out and lay a spirit level across both brackets — a millimetre or two of difference is enough. Once the brackets are true, a wrap of masking tape round the tube at the high side corrects any residual tracking.
Can I re-tension a roller blind spring?
On a spring blind, yes: pull it fully down, lift the tube out of the brackets, hand-roll two or three turns, and refit. Side-winder chain blinds have no spring — if they will not hold, the clutch is worn and needs replacing.
Can I cut a roller blind narrower?
Many are designed to be trimmed, and the tube cuts with a hacksaw and the fabric with sharp scissors. The critical part is squareness: mark against a long straight edge with the fabric flat and fully unrolled, because an out-of-square cut makes the blind track sideways for ever.