Awning Sitting Lower on One Side? Find the Cause Before You Adjust
A retractable awning that sits lower on one side most often has its two arms set at slightly different pitches, a shoulder bracket that has slipped on the torsion bar, or one arm spring that has weakened. Less often, and more seriously, a wall bracket is pulling away. Rule out the bracket first, then measure, then adjust the low arm in small steps. This page shows how to tell the causes apart and level the awning safely.
Key takeaways
- Check the wall brackets before anything else. A bracket that moves when you push up on the front bar is a stop-using-it fault, not an adjustment.
- Measure the front bar height at both ends fully extended and again half extended. A difference that is constant points to pitch; one that changes with extension points to a spring or the fabric.
- A difference under about 1/2 in (13 mm) is hard to see and usually not worth chasing. Over 1 in (25 mm), it is visible and starts to cause tracking and water problems.
- Adjust the low side up rather than the high side down, unless headroom or rain runoff says otherwise.
- Arms are spring loaded at all times. Support the arm, change pitch in quarter turns, and never unbolt an arm under load.
Fast diagnosis
| What you observe | Likely cause | Urgency |
|---|---|---|
| Bracket or anchor moves, gap behind bracket, cracked mortar or crushed siding | Mounting failing | High: retract and stop using |
| Same difference at full and half extension | Arm pitch set unequally | Low |
| Shoulder bracket rotated on the torsion bar, scuff marks show it moved | Shoulder clamp bolts loose or slipped | Medium |
| Low side bounces more and feels softer when pushed | Weak or failing arm spring, or stretched arm cable or belt | Medium |
| Difference appeared after a storm | Arm bent, shoulder slipped, or bracket loosened | Medium to high |
| Front bar curved, low in one region rather than at one end | Bent front bar | Medium |
| Difference only partly extended, level at full extension | Coned fabric roll or unequal fabric stretch | Low |
| Brackets level with each other but awning still low one side | Torsion bar twisted, or the arms themselves differ | Medium |
First, rule out a failing bracket
Retract the awning and look at every wall or soffit bracket. Then extend it and, standing on firm ground, push up firmly on the front bar near each arm while a helper watches the brackets. Look for:
- Any visible movement of a bracket relative to the wall.
- A gap opening behind the top of a bracket.
- Cracked mortar, spalling brick, crushed siding or stucco cracking around anchors.
- Rust streaks from anchors, or anchor heads that have pulled out.
- A torsion bar that has shifted sideways in its brackets.
Lateral arm awnings put large leverage on their top anchors, and a bracket that has started to move will keep moving. If you see any of this, retract the awning and do not use it until it is properly re-anchored. Our guides to masonry mounting, siding and stucco mounting and studs, rafters and blocking explain what correct fixing looks like.
Measure the difference properly
- Extend fully in calm weather, and let the arms settle for a minute.
- Measure at both ends. From the patio, or from a level string line between two points, measure to the underside of the front bar directly in front of each arm. Patios slope for drainage, so a string line or laser level is more reliable than the deck surface.
- Repeat at half extension. Note whether the difference stays the same, grows or shrinks.
- Check the brackets are level with each other using a level along the torsion bar or the cassette.
- Check projection at each end. Measure from the wall to the front bar at each end. A shorter arm reach on one side suggests a bent arm.
Fixes, from easiest to hardest
1. Re-tighten a slipped shoulder (low cost)
If the shoulder bracket has rotated on the torsion bar, there are usually scuff marks showing where it was. With the awning partly extended and the arm supported, loosen the clamp bolts just enough to rotate the shoulder back, then tighten them to the manufacturer's torque. How shoulders clamp to the bar is shown in front bar and shoulder brackets.
2. Adjust the arm pitch (low cost)
Most shoulders have a pitch bolt or threaded rod that tilts the arm. Raising the low side is usually preferable, since it keeps headroom and avoids reducing slope on the high side. If the awning already ponds water, lowering the high side would make that worse; read awning pitch explained first. The general adjustment procedure, including sagging front bars, is in fixing awning sag and pitch.
3. Deal with a coned fabric roll (low to moderate)
If the awning is level fully extended but not when partly extended, the fabric roll may be thicker at one end, so the two edges pay out at different rates. Fix the roll and the partial-extension tilt goes away. See fabric rolls unevenly.
4. Replace a weak arm or arm belt (pro)
A soft arm that bounces more than the other has a weak spring or a stretched cable, belt or chain. Pitch adjustment can mask this for a while, but the arm will keep sagging and may fail suddenly. Replacement requires the arm to be de-tensioned and is best done by a technician. Arms are usually sold in matched sets or by exact projection and model.
5. Correct a bent front bar, arm or twisted torsion bar (pro)
Wind and ladders are the usual causes. A bent aluminum front bar or arm should be replaced rather than straightened. A twisted torsion bar often means the brackets were overloaded; have the mounting checked at the same time. Our wind safety guide explains the wind speeds that cause this.
6. Re-anchor or re-mount (pro)
If a bracket has moved, the anchors need replacing with correctly sized fixings into solid structure, often with new bracket positions. This is not an adjustment job.
When to call a pro
- Any bracket or anchor moves, or the wall is cracked around a fixing.
- An arm feels noticeably softer than the other, or you can see a frayed cable or belt.
- Pitch adjustment has run out of range without leveling the awning.
- The awning is mounted high (second floor or over a slope) and you cannot support the arms safely.
Before paying for a visit on a new awning, check the warranty: uneven arms on a recent installation are often an installation or factory issue. See awning warranties explained.
Frequently asked questions
Should a retractable awning be perfectly level side to side?
Close to it. A difference of up to about 1/2 in (13 mm) across the front bar is normal and hard to see. Some installers deliberately set one end slightly lower on wide awnings to shed rain to a corner, which is fine as long as the fabric rolls straight.
Can I level the awning by adjusting the wall brackets?
Only if the brackets themselves were installed out of level, and only by re-mounting with the awning de-tensioned or removed. In normal use, level the front bar with the arm pitch adjustment.
Why did my awning suddenly drop on one side?
A sudden drop usually means something moved: a shoulder slipped on the torsion bar, an arm cable or belt failed, or a bracket loosened. Retract it and inspect before using it again.
Will an awning that is lower on one side damage the fabric?
Over time, yes. The fabric is tensioned unevenly, tends to track toward one side, and can rub the end cap or develop diagonal creases. Water also collects at the low corner.
Do motorized awnings go out of level more than manual ones?
No, the motor does not affect side-to-side level. A motor set to close too hard can, however, overload arms and brackets over time, which can contribute to slipping. Make sure the upper limit stops at light contact.
Sources and standards consulted
- Tubular motor troubleshooting, limit-setting and remote pairing guides (manufacturer documentation)
- Lateral arm awning service manuals (pitch, arm and spring adjustment) (manufacturer documentation)
- Retractable screen manufacturer service and re-tensioning instructions (manufacturer documentation)
See how we research for our sourcing and verification process.