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Making Adjustments To Internal Bifold Doors

Bi-fold doors make a great choice in confined spaces, or where you’d like to create a large, temporary barrier between two rooms (or between your home and the outside world).

But an internal bifold door won’t be up to much if it doesn’t properly fit the opening it’s installed into.  If you’ve got an irregularly-shaped opening that a standard-sized door won’t fit into, then you’ll have a problem.  Likewise, if you’ve bought a solid-wood door, you might find that it changes shape after it’s been installed, causing it to catch against the frame. Problems can also arise from a change of carpet – if you’ve moved from a hardwood or tiled floor to a thick, bushy carpet, then you’ll probably find that the bottom of your folding doors will catch against it.

These problems can sometimes be corrected by adjusting the position of the door within the frame – but sometimes, it trimming a bi-fold door down might be necessary.  In this article, let’s consider how this might be done (and when it should be done).

Time Required

In order to do the best possible job, you’ll want to take your time.  Set aside an entire weekend and get the job done properly; that way you’ll have time available to cope with any setbacks.

Making Adjustments to Internal Bifold Doors: Step-by-Step Instructions

Let’s take a look at how we might go about adjusting bifold doors.

Explore alternatives

Removing a piece of your door is an irreversible operation.  If your door is catching against the frame or the carpet, then you’ll want to take a look at other ways of correcting the problem.  Take a look at the pivot on the bottom of the door.  If it can be raised to correct for any dropping, then you’ll be able to solve the problem without removing or altering the doors themselves.  Check that the hinges are correctly installed, and that the frame hasn’t warped.  If you’ve got no other recourse, then you can start making changes to the doors.

Measure the amount that needs to be removed

If your doors are catching against the carpet, then open them to see how far up the door the carpet has moved.  It’s usually just a few millimetres.  Make a mark on the door using pencil.  This will come in useful once you’ve removed the door from the frame.

If you’re trying to make a door fit a frame that’s slightly smaller than the regular sizes, you’ll want to make very precise adjustments to each of your doors.  Measure across the frame diagonally, from top-right to bottom-left and vice versa.  These two measurements should be within 5mm of one another.  Next, take measurements of the width and height of the door, taking three measurements for each and using the smallest as your baseline.  If you notice severe discrepancies here, you’ll want to adjust the frame before thinking about adjusting the doors.

Calculate ideal measurements

Before you start marking and cutting, consider how wide and tall your doors should be.  If your bifold doors are too wide, then you’ll need to take a little bit off the sides.  If your bifold doors are too tall, you’ll need to take a little bit off the top and bottom.  It’s important that you take an equal amount from each side of the door, for two reasons:

  • Removing too much wood from one side can result in a ‘lopsided’ look.

  • Unless the door is solid wood, you’ll only have so much ‘lipping’ on each side to work with.

Remove doors

The next step is to remove the doors from their pivots. This can sometimes be tricky – you’ll want to proceed as though you’re installing the bifold door, but in reverse.  Adjust the pivots and the top and bottom of the door to generate the maximum possible slack.  If you find that you still can’t remove the door, you might have to resort to using a crowbar. If you’re going to do this, be extremely careful that you don’t damage the doors themselves.

You can find more information in our Bifold Door Problems and How To Fix Them guide.

Make your marks

Cover the edges you intend to trim with masking tape, and then mark with a pencil where you’re going to trim the door to.  Draw a line and measure it thoroughly to ensure that the final result will be straight and square.

Get sawing

By now, you’re probably ready to start sawing.  Proceed carefully, and make sure you’re working on a flat surface.  Saw up to – but not over – the line you’ve drawn, keeping the masking tape on throughout.  You might wish to score across the line using a ruler and a Stanley knife, in case the tape comes away from the door midway-through.

Finish up

Once you’ve finished trimming, sand the new edge down until it’s totally smooth, and re-install the door into the opening. If everything fits perfectly, then you’re almost done – but you’ll need to apply a coat of finish to any places you’ve cut and sanded.

Additional tips

Making these sorts of adjustments to an old set of bi-folding doors is a great way to extend their lifespan – but there’s only so much adjustment we can make before the doors cease to function effectively.  If you find that you need to shave more than a few millimetres from each side, then you might find it easier to just buy a new set.  While this will mean digging into your wallet, the cost may be justified by the stress and labour you’ll avoid.

In conclusion

Adjusting bi-fold doors is something that requires a great deal of planning and preparation – if you get it wrong, after all, there’s no way to ‘un-adjust’ the door and restore it to its prior glory.  The safest course of action is usually to opt for a regular-sized door, or to bring an expert in to install an irregularly-sized one.

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