How to Adjust French Doors: Alignment, Hinges & Closing Problems

French doors rely on two leaves meeting accurately, so even a small change in hinge position or frame alignment can make the master leaf difficult to lock. Before adjusting anything, identify whether the problem is dirt, hardware, leaf alignment or movement in the frame. This guide explains how to adjust French doors and when to call an installer.

Adjustment points vary between products. For doors from our French doors range, use the Crystal manufacturer instructions for the exact hinge and locking system before turning adjustment screws.

Start by Cleaning the Doors

Wipe the frame, threshold and seals with mild soapy water and a soft cloth. Clear dirt from the bottom of the frame and make sure drainage paths are not blocked. Grit at the threshold can make a door feel misaligned when the real problem is contamination.

Do not use abrasive pads or strong solvents on uPVC, seals or coated hardware.

Work Out Which Leaf Has the Problem

Open and close the master leaf on its own, then release and operate the secondary leaf. Notice whether the issue occurs only when both leaves meet. This helps separate a master-hinge problem from a central alignment or secondary-leaf problem.

If the lock works smoothly while the door is open but becomes stiff when closed, alignment with the keeps is likely the cause.

Check the Frame Before Adjusting Hinges

Use a long level on the jambs, head and threshold. Check whether the frame is visibly bowed or has moved away from the surrounding wall. Measure diagonals if necessary.

If the frame or structural head has moved significantly, hinge adjustment is not the correct fix. Arrange professional assessment before forcing the doors.

Inspect the Gaps Around the Master Leaf

Look at the top gap, hinge-side gap and clearance over the threshold. If the lock side is lower than the hinge side, the leaf may have dropped. Uneven compression against seals can indicate lateral or compression adjustment is needed.

Take a photo and mark the starting position before any changes so you can reverse an unsuccessful adjustment.

Understand uPVC Hinge Adjustments

Many modern uPVC hinges offer some combination of height, sideways and compression adjustment, but the screw positions and ranges differ. Remove caps only where the manufacturer indicates and use the correct Allen key or tool.

Make small adjustments, often a fraction of a turn, then retest. Large random changes can move the leaf farther out of alignment.

Adjusting Door Height

If the master leaf rubs the threshold or sits low at the centre, height adjustment may help. Follow the product instructions to raise or lower the leaf evenly. Keep enough clearance at the head and do not wind the hinge to the end of its adjustment range.

If a large lift is needed, inspect the glazing packers and frame because the issue may not be hinge adjustment alone.

Side-to-Side Adjustment

Lateral adjustment moves the leaf toward or away from the hinge side. This can help centre gaps or align the meeting stiles. Adjust top, middle and bottom hinges in a controlled way so the leaf remains straight.

Do not move the leaf so far that seals stop contacting or hinge clearances become unsafe.

Compression Adjustment

Compression controls how firmly the leaf closes against weather seals on systems that provide this adjustment. Too little compression can contribute to draughts; too much can make handles and locks difficult to operate and can over-compress seals.

Use only the range permitted by the hinge design and aim for consistent seal contact.

Aligning the Secondary Leaf

The secondary leaf must seat correctly before the master leaf can lock against it. Check top and bottom shoot bolts or retaining hardware where fitted. If the secondary leaf is high or low, use the appropriate hinge adjustment rather than enlarging keeps unnecessarily.

Make sure the leaf is fully secured in its normal closed position before evaluating the master lock.

French Door Lock Is Hard to Lift

With the master leaf open, operate the handle and lock gently. If it is smooth, close the door and observe which lock point meets its keep first. Misalignment can put excessive load on the handle.

Correct leaf alignment before changing the keeps. Forcing a multipoint mechanism can damage the gearbox.

Adjusting Lock Keeps

Some keeps allow minor position adjustment. Mark their original location and make very small changes only after hinge alignment is correct. The aim is for lock points to engage smoothly while maintaining appropriate seal compression.

Do not grind away large sections of a keep to accommodate a sagging door.

Master and Secondary Leaves Rubbing in the Centre

Central rubbing can result from both leaves moving toward each other, one leaf dropping or the frame narrowing. Compare the vertical gaps at top and bottom. Adjust the responsible leaf rather than moving both without diagnosis.

If the frame has bowed inward due to fixing pressure or structural movement, an installer may need to correct the frame instead.

Door Rubs at the Threshold

Clean the threshold first. If rubbing remains, check whether the whole leaf is too low or only the lock corner. A whole-leaf height adjustment differs from correcting a dropped corner.

Do not cut or grind a uPVC leaf or threshold to create clearance. These are factory-designed profiles.

Door Rubs at the Head

Check whether the leaf has been adjusted too high or whether the structural head/frame has dropped. A problem affecting both leaves near the centre can indicate frame movement rather than individual hinges.

Persistent head deflection should be assessed by a professional.

Maintaining Seals and Drainage

Inspect gaskets for tears, displacement or permanent flattening. Clean them gently and replace damaged system-specific seals where necessary. Clear drainage outlets so water can leave the frame as designed.

Never block a drainage opening because it appears to admit air; it may be essential to weather management.

Maintaining Handles and Locks

Check that handles are secure and return normally. Use only lubricants recommended by the lock manufacturer and apply sparingly. Avoid heavy oils that attract grit or affect seals.

If the handle remains stiff with the door open, the lock may need servicing rather than adjustment.

When to Call an Installer

• The frame has moved or bowed significantly.
• The structural head appears to sag.
• Glass is cracked or a glazed leaf has shifted noticeably.
• Hinges are damaged.
• The lock is stiff even when the leaf is open.
• Adjustment screws are already at their limit.
• The doors are under a warranty that requires approved service.

Preventing French Door Problems

Correct installation is the best prevention. A frame that starts square and level gives the hinges and locks a stable reference. Read our how to fit French doors guide if you are planning a replacement.

Clean the doors regularly, keep drainage clear and never force a stiff lock. Small alignment issues are easier to correct before they strain the hardware.

French Door Maintenance Checklist

• Clean frame and threshold.
• Clear drainage outlets.
• Inspect seals.
• Check hinge fixings.
• Compare gaps around both leaves.
• Test master lock while open and closed.
• Check secondary-leaf retaining hardware.
• Use approved lubricant only where specified.
• Arrange service for structural or major hardware issues.

Frequently Asked Questions

Why do my French doors not meet in the middle?

One or both leaves may have moved, the frame may be out of square or hinge adjustment may be needed. Check gaps and frame alignment before altering locks.

Can uPVC French doors be adjusted up and down?

Many hinge systems allow height adjustment, but the method and range are product-specific. Use the exact manufacturer instructions.

Why is my French door handle hard to lift?

If the handle is smooth when open, lock points are probably misaligned with their keeps. Correct door alignment first.

Should I lubricate uPVC door hinges?

Only with a lubricant suitable for the specific hardware and in the manner recommended by the manufacturer.

How often should French doors be checked?

Regular cleaning and periodic visual checks are sensible, with more frequent attention in exposed or high-use locations. Follow the product maintenance schedule.

Keep Your French Doors Working Correctly

If you are replacing rather than repairing a set, compare our uPVC French doors and use our French doors buying guide to choose the right size, glazing and configuration.