Creating a seamless transition from an interior to the great outdoors, bifold doors are lightweight and easy to open.


If you fancy yourself as a bit of a DIYer and you’re able to fit conventional windows and doors, then you should be able to fit a bifold door without too much trouble – the crucial thing to remember is that the threshold, cill, head and jambs must be fitted level or the bifold doors won’t operate properly. The frame mustn’t be pulled out of shape or bowed by the fixings or by any unsupported weight from above the doors.


Follow these simple steps to fit your bifold doors:


1. Outerframe


All four sides of the outer frame must be fixed. The frames are non-load bearing and no weight must be applied to the head. First, fit the frame into the aperture and pack it square, checking the head and cill detail to make sure there are no bows present.


Pre-drill the cill, jamb and head sections – you may use fixing lugs on the head and jambs. The corner fixings must be between 150mm and 250mm from the external corner. Each head jamb and cill section should have a minimum of two fixings.


• Frame width up to 1,200mm: minimum of three fixings
• Frame width of 1,201mm to 2,400mm: minimum of four fixings
• Frame width of 2,401mm and above: minimum of five fixings


2. Inserting the pins


You should have received a kit with the bifold door that includes three pins: one smooth metal; one ridged metal; and a roller pin with a nylon wheel.


Establish which is the top end of the door – it’s easier to set the door on its end and use a stepladder to access the top. There are two holes – locate the hole that’s at the hinge end. Push the smooth pin into the hole at the hinge end, making sure it goes in as far as possible. Tap it lightly with a hammer if necessary.


Next, push the roller pin into the other hole at the top end of the door, again tapping this lightly to ensure it goes in all the way. Take great care not to hammer it too hard as the wheel can break. Use a rubber mallet rather than a hammer if this is easier for you.


3. Fitting the metal guide


Now you should only have the rigged pin left to insert. You may need two sawhorses at this point to support the door but if you don’t have any just lay the door on the floor. Insert the final pin at the hinge end.


Screw the top metal guide into the doorframe, making sure it’s positioned so that the small metal hinge-rest is closest to the frame. The L-shaped bracket should be installed at the junction of the doorframe and the floor.


Two screws will normally be sufficient in the doorframe but the bracket has an additional hole so that it can be screwed into the floor for extra strength. Make sure you’ve installed the L-shaped bracket in the correct direction, with the slit with the teeth in a horizontal position.


Push the spring assembly into the end of the top guide – this should simply snap in by hand at the opposite end to the hinges. You must not use a hammer as this could break it.


4. Attaching the door


It’s relatively simple to affix the door, although it may require two people. After the smooth pin has been inserted into the top metal guide, swing the bottom of the door into place with the ridged pin resting in the L-shaped bracket.


If in any doubt, you should enlist the help of professional installers.