A pole that dips in the middle is one of the most common complaints we hear, and it is nearly always fixable. It is also usually a symptom of something specific rather than a poor quality pole, so it is worth diagnosing before replacing anything.
Cause one: the span is too long for the diameter
This is by far the most common reason. Every pole has a practical unsupported span, and it drops sharply as weight increases.
As a rough guide for lined domestic curtains, a 19mm pole is comfortable up to about 120cm between brackets, a 28mm pole up to about 200cm, and a 35mm pole up to about 250cm. Heavy interlined curtains reduce all of those figures considerably.
If your pole exceeds those spans, the fix is a centre bracket rather than a new pole. Use a passing bracket so the curtain rings glide over it instead of stopping against it. Adding one support halves the span and typically doubles the load the pole can carry.
Cause two: the curtains are heavier than the pole was chosen for
People often replace curtains without thinking about the hardware. A pole that coped happily with unlined cotton may struggle with interlined velvet, which can be three or four times the weight.
If the curtains have changed, check the pole is still appropriate. Either add support or move up a diameter.
Cause three: the brackets have shifted
Sometimes the pole is fine and the fixings have moved. Look closely at the wall where each bracket meets it. Hairline cracks in the plaster, a slight gap behind the bracket plate, or a bracket that rocks when you push it are all signs the fixing is working loose.
This usually means the original fixing was into plasterboard rather than solid timber or masonry. The fix is to remount properly: find the studs or the noggin above the window and fix into timber, or fit a timber batten across the studs and mount the brackets onto that. Plugging the same failed hole rarely holds for long — move to fresh material if you can.
Cause four: the pole itself is lightweight
Diameter alone does not tell you how strong a metal pole is. Wall thickness matters just as much. A thin-walled 28mm pole will bow where a thicker-walled one of the same diameter will not.
If a pole has bent permanently rather than simply drooping between supports, it has been overloaded and will not recover. Straightening it will weaken it further. Replace it with something more substantial.
How to check which it is
Take the curtains off. If the pole springs back straight, the problem is load and span — add a centre bracket or increase the diameter. If it stays bent, the pole is done.
With the curtains off, also grip each bracket and try to move it. Any give at all means the fixing needs attention regardless of anything else.
Preventing it next time
Work out the curtain weight before choosing hardware, not after. Add a centre bracket to anything over about 200cm as a matter of course. Fix into solid material rather than plasterboard alone. And when in doubt, go one diameter up — the extra cost is small and it removes the problem entirely.
If you are unsure what your window needs, send us the width and an idea of the curtain weight and we will tell you what will hold.