How To Fit A Bifold Door

Posted at 11/16/23

Wondering how to fit a bifold door? We have put together this detailed guide to run you through the process. Installing bifold doors is a complex process and should always be left to experienced installers. 

Fitting A Bifold Door

The first step is to carry out measurements. When measuring, remember to allow the required expansion gap of 5mm on either side of the frame. This will give you room to square the frame in the opening. 

Care must be taken to ensure the structure is secure and safe to remove the existing door. Before any installation work is started, make sure to check the style, size and condition of the new door against the survey size and actual aperture sizes.

Removing An Existing Bifold Door

To make the removal process as easy as possible to handle, start by removing as much of the old bifold door frame and glazing as possible. This will reduce the overall weight of the old profile. Begin by loosening the hinges and removing the door leaves. Break the bond between the frame and the wall by running a sharp blade around the edge of the frame. When ready, remove the fixings and the old frame.

Once the old bifold door is removed, you will need to clear off any old sealant or debris left around the opening. Make sure to remove any loose mortar before rechecking the measurements. 

Preparing And Fitting The Cill

It is vital that the ends of the cill are completely filled with silicone, and the end caps are fitted. Failure to do this could result in moisture tracking on the cill and into the brickwork. 

Put the cill into position and check the level. If needed, use packers along the cill to make it level. Once this is achieved, remove and seal underneath with sealant to hold it in place. Position the sill in the aperture. Run a bead of silicone along the edge and fill up span before fixing the door to prevent the possibility of water blowing through the joint and moisture from tracking along the cill and into the brickwork. Remove the bifold door frame and any corner protectors. 

How To Fit The New Bifold Door

Check the frame labels to ensure that the bifold door is fitted in the right orientation. Carefully place the frame into the opening above the film, making sure that the frame is central and the 5 millimetre expansion gap on either side of the frame is maintained. 

Using a spirit level, plum one side of the frame and place two temporary fixings 150 millimetres from each corner. At this stage, do not fully tighten the fixings. It is advised that you pilot drill first to ensure that the bifold door thermal break does not crack. Care should be taken to not over tighten the fixings. 

Packers must be used adjacent to each fixing point. These should span the full width of the bifold door frame, and once the fixings are tightened, they will prevent the frame from distorting while ensuring that the outer frame is fitted square. 

Repeat this process on the other side of the bifold door frame using a spirit level to ensure that the frame is parallel and true in the opening. Once both sides are level, parallel and plumb, place a fixing in the centre of the head, again using packers. Now put the rest of the fixings at 600 millimetre intervals around the head and sides, not forgetting to tighten the original fittings at the end. It is vital to ensure that the outer frame is fitted square, plumb and level. Fit the door handle and check the door operation. If everything is fitted correctly, the bifold door should glide freely. 

Bifold Door Double Glazing Installation

Before installing the glass panes, carefully remove the beading and clean any dust from the frame and drainage holes before installing the glass. It is vital that you don’t mix the beads up as they need to go back in the same position. 

The glass units will all be the same width unless there is a master traffic bifold door. The glass unit for a master traffic door is 6 millimetres narrower so that it does not interfere with the door lock. It is vital to ensure that the narrow unit is fitted in the master traffic door. 

Starting with the leaf, insert a glazing packer on the bridging packer that will come pre-fitted. Place the glass onto this packer. You will notice that there is a gap between the edge of the glass and the bridging packers. This is to allow you to insert glazing packers in the bottom corner of the hinge side and the top of the D handle side in order to secure the glass in place. This is the toe and healing process, and when done correctly, it transfers the weight of the glass to the hinges. It allows the top hinge to hold the bifold door sash in place. 

Once you have positioned the packers in the right location, secure them in place with silicone. Once the unit is in square and the sash is parallel in the outer frame, refit the beads in the sash. Place the short ones in first, making sure to place them in the correct location, and then the long ones. Take care not to scratch the beads when you are refitting them. 

Now move on to leaf two, repeating the process but this time to the opposite, as a standard toe and heeling method. First, insert glazing packers on the bottom corner of the hinge side and then insert glazing packers on the top of the D handle side. Once the unit is square, and the sash is parallel in the outer bifold door frame, refit the beads in the sash. 

Finally, move on to the master traffic bifold door repeating the process, inserting the glazing packers on the bottom corner of the hinge side and then inserting the glazing packers on the top of the handle side. You should also insert packers on the top and bottom of the lock, fixing all packers with silicone to prevent movement. 

Once the unit is in square and the sash is parallel in the outer frame, refit the beads in the sash. After this, check the operation of the door. Once all the leaves are glazed, fit the wedge gasket. Measure the gasket against each sash and cut the length for the width and height. Spray some window cleaning fluid onto the window to ease the fitting. Start at the end of the sash and insert the end of the gasket between the glass and the beading. Move along the edge, slightly skipping sections causing slight loops and then work to insert more. Make sure you fit the gasket the right way round, and do not overstretch it. Repeat this action until the gasket covers the length of the sash. 

Next, put pressure and move your thumb to the left, ensuring the gasket is fully inserted between the glass and the beads. Once you have completed hanging and glazing the bifold door, the frame will require sealing internally and externally all around the perimeter. After this, fit the magnets that hold the leaf together once opened. Finally, clean the internal working area. 

Finishing The Bifold Door Installation

Remove any protective tape from the outside bifold door frame and clean the door and frame to remove any dust before sealing the frame to the wall. Run masking tape along the edge of the frame to help create a neater finish before running a smooth bead of sealant between the frame and the brickwork. Once the sealing is complete, remove the masking tape to reveal the sleek, neat finish. Fit the drainage caps and check the operation of the doors. The final step is to make any adjustments needed. 

Bifold Door Costs

We hope that this guide has been helpful, instructing you how to fit a bifold door. 

If you are looking for bifold door prices, please take a look at our online quoting tool. Simple to use, you can receive a quote relevant to your specifications.

If you are looking for a bifold door supplied and installed, please take a look at our find an installer tool.