One of the most frequent faults that I come across in the nature of my repair business is dropped or catching PVC-U doors and windows.
Most people outside the trade (and quite a few that work within it) do not know how to set up doors and side hung windows properly to make sure that they do not drop out of position after a few weeks of use. This process is called ‘Toe and healing’.
PVC-U doors and windows (especially side hung windows) actually rely on the glass unit or panel to hold and keep the opening part of the door or window straight and level. This is important to ensure that all the locks stay in line and the frame does not drop or scrape along the bottom cill.
The correct procedure is this:
The glass needs to be sat on glazing packers to hold the frame square, these to be positioned as follows:
Place one packer (usually one about 4-6mm thick by the width of the unit) on the bottom rail in the corner at the hinge side of the door, place a second packer vertically up the hinge side at the bottom corner next to the first packer thus forming a corner.
At the opposite top corner, place one packer on the top rail and one in the top corner on the vertical door locking side. (these will probably have to be held in place with silicone sealant or similar.)
This will mean that the glass unit is held at opposite corners and will sit square in the frame.
Position the glass into the aperture, check to see if the glass is making contact with the packers at the top corner. If not, and the gap is more than say 4mm at the top, then lift the glass unit up and fit another packer on top of the packer at the base of the unit to raise the glass up a little bit until it touches or nearly touches the packer at the top of the glass.
Do the same for the ones on the bottom and top side packers. The idea is to ensure that the glass is held squarely and securely at both opposite corners .
Try and close the door, if it catches at the bottom, It will be necessary to place another packer on top of the glass at the top corner, this is achieved by having an assistant pull up the door vertical bar to create a gap on top of the glass. Once this gap is there it is easy to push another packer in which will hold the door frame in the raised position. Once it does not catch anymore, complete the fitting of the glazing beads.
These packers are available in various thicknesses and also in a range of sizes to suit different widths of glass units. It is crucial to use packers that are the same width as the glass unit, too narrow and they could get caught in between the panes and cause breakage, too wide and they could impede the fitting of the glazing beads.
Once the door has been packed, it helps to actually hang on the door, check the operation and then repeat the process,
Hanging on the door speeds up the settling down process of the installation and if done should stop the need for a re-adjust after six weeks or so once the door has settled down with use.
If a door starts to catch, its quite simple to remove the glazing beads and then re-pack back to the correct position.
Source by Paul Gardner