Fitting Bi-Fold Doors The Right Way

We have all had jobs where our customers are looking to create a large open space leading into their garden using bi-fold doors, but how do you get the perfect look and finish while keeping costs reasonable and ensuring you don't get any problems down the line. In this post we share some tips from professional fitters, to help you get it right.

Step 1 - Preparation

Remember, when measuring doors, ensure you allow the required expansion gap of five millimetres on both sides 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 it is safe to remove the existing door. Before any installation work is started, ensure to check the size, style, and condition of the new door against the survey size and the actual aperture sizes.

Step 2 – Remove The Existing Door

To make it as easy as possible to handle, remove as much of the old frame and glazing as possible. This will reduce the overall weight of the frame. 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 remove the old frame. Once the old door is removed, you will need to clear off any old sealant or debris left around the opening. Removing loose mortar before rechecking the measurements.

Step 3 – Fit The Cill

It is vital that the end of the cills is 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 the cill is level, remove and seal underneath with enough sealant to hold in place. Position the cill in the aperture. Run a bead of silicon along the edge and cill up stand 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 frame and corner protectors.

Step 4 – Fitting The New Bi-Fold

Check the frame labels to ensure that the door is fitted in the right orientation. Carefully place a frame into the opening above the cill making sure that the frame is central and the five millimeter expansion gap either side of the frame is maintained.

Using a spirit level, plumb one side of the frame and place two temporary fixings one hundred and fifty millimeters from each corner. At this stage, do not fully tighten the fixings. It's advised you pilot drill first to ensure that the thermal break does not crack. Care should be taken not to overtighten the fixings. Packers must be used adjacent to each fixing point. These should span the full width of the frame and once the fixings are tightened, they will prevent the frame from distorting and help ensure that the outer frame is fitted square.

Repeat this process on the other side of the 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 center of the head again using packers. Now put the rest of the fixings at 600mm 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 doors should glide freely.

Step 5 – Installation Of THE Glass

Before installing the glass panes carefully remove the beading and clean any dust from the frames and drainage holes before installing 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 door as in the case of this three pane door. The glass unit for a master traffic door is six millimeters 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 first leaf, insert a glazing packer on the bridging packer that will become 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 enable you to fit 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 turn healing process and when done correctly it transfers the weight of the glass off the hinges and allows the top hinge to hold the sash in place.

Please see our other video for further details on how to do this in more detail here - How To Toe & Heal A Bi-Fold

Once you've 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, ensuring 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 do the opposite as a standard toe and healing 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 frame, refit the beads in the sash. Finally, move on to the master traffic door, repeating the process, inserting the glazing packers on the bottom corner of the hinge side, and then insert the glazing packers on the top of the handle side.

Also insert packers on the top and bottom of the lock. Fixing all packers with silicone to prevent movement. Also the unit is in square and the sash parallel in the outer frame refit the beads in the sash. 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 brace some window cleaning fluid onto the window to ease the fitting.

Start at the left of the sash and insert the end of the gasket between the glass and the beading. Moving along the edge slightly skipping sections, causing slight loops and then insert more. Make sure you fit the gasket the right way around and do not over stretch it. Repeat action until gasket covers lengths of thatch. Then put pressure and move your thumb to the left, ensuring gas it's fully inserted between the glass and the beads. Once you've completed hanging and glazing the doors, the frame will require sealing internally and externally all around the perimeter of the frame. Then fit the magnets which hold the leave together once opened.

Finally clean the internal working area.

Step 6 – Finishing The Installation

Remove any protection tape from the outside frame and then clean the door and frame to remove any dust before sealing the frame to the all. Run masking tape along the edge of the frame to help create a neat finish before running a smooth bead of sealant between the frame and the brickwork.

Once sealing is completed remove the masking tape to reveal a neat finish.
Fit the drainage caps.

Check the operation of the doors and any adjustments needed.
For more information, refer to our bi fold door installation manual.

Express Trade Windows will save you time, money and hassle 

If you are in the Lincoln area, and need a trade depot that is going to look after you and your business, look no further than Express Trade Windows of Lincoln, we pride ourselves on taking care of our customers, giving you the best products and we will not be beaten on price, give us a call on 01522 516607 and price up your next job.