How do I fit a curtain pole or track in a bay window?

A bay is three or five short spans meeting at angles, and every one of the angles is a place where a curtain has to change direction under its own weight. That is a genuinely difficult mechanical problem, which is why bay windows are where curtain systems most often disappoint — and why the choice of system matters more than the fitting.

Safety

What you'll need

• Long tape measure and a sliding bevel or an angle finder
• Paper and pencil for a scaled sketch
• Cable and pipe detector
• Drill, masonry bits and fixings for the wall
• Stable step platform, and a second person
• Timber batten across the window heads (optional)
• Bendable track, or a jointed pole kit with corner connectors

Step by step

1. Draw the bay and measure every face and angle.A sketch with the length of each face and the internal angle at each corner. Use a sliding bevel or an angle finder — bays are frequently a degree or two off the angle they appear to be, and suppliers of curved tracks need the real figures.
2. Decide first whether curtains need to cross the corners.This is the decision that determines everything. If each face has its own curtain, three separate straight poles are simple, cheap and reliable. If one pair of curtains must draw round the whole bay, you need a system designed to do that.
3. Choose the system honestly.A jointed pole with passing corner connectors looks best and draws acceptably if the rings are the passing type. A bendable or made-to-measure curved track draws far more smoothly and disappears behind the heading. A corded track is worth the extra on a large bay, because reaching into a bay to close curtains is awkward and a cord saves the fabric.
4. Fit a batten across the window heads if the structure is unhelpful.Bays typically have a separate lintel over each face, ending before the corner, so the corner itself often has nothing behind it. A batten spanning the whole bay, fixed into the solid parts, gives fixing points everywhere including at the angles. Paint it to match.
5. Scan the whole head, including the returns.Bay windows commonly have wall lights, and switch drops run in the returns. Scan every position before drilling.
6. Set a single level line all the way round.Use a long level or a laser from one end to the other. Each face measured up from its own window head will step at the corners, because the windows are rarely all at the same height.
7. Fit the brackets at close centres on the long faces.Bay curtains are heavy and the front face is often the longest span in the room. Support at 800mm to 1m centres rather than at the ends only, and always immediately either side of each corner.
8. Support each side of every corner.The corner connector is the weakest point of a jointed pole. A bracket within 100 to 150mm of each side of it stops the joint carrying bending load.
9. Check the curtains actually pass the corners before finishing.Hang one curtain and draw it fully round. Passing rings or a corner-friendly track glider should ride over without snagging. Fixing this after the curtains are made up is much harder.
10. Allow stack-back at the ends of the bay.The open curtains have to go somewhere, and in a bay they usually stack onto the returns. Extend the pole or track 150 to 250mm past the last window onto the flat wall so the glass stays clear.

Tips

• Made-to-measure curved track costs more than a jointed pole and works better in almost every respect. If the curtains must draw round the bay, it is usually the right purchase.
• In a bay with a radiator under the front window, sill-length curtains often work better than floor-length ones. See the radiator guide for what full-length curtains do to the heat.
• If the bay has a window seat, treat the seat as the floor for the drop and finish the curtains just above it.

Common mistakes

• Assuming the bay angles are 45 degrees — They frequently are not, and a curved track made to the wrong angle does not fit. Measure with a bevel.
• Measuring each face up from its own window head — The windows in a bay are often at slightly different heights. Set one level line round the whole bay instead.
• Using ordinary rings on a jointed pole — They will not pass the corner connectors. Passing rings are a specific product and they are what makes a jointed pole draw.
• Bracketing only at the ends of each face — Bay curtains are heavy and the spans are awkward. Support at 800mm to 1m and immediately either side of each corner.

If it doesn't work

Questions people ask