This guide is intended to give you an insight into the basic principles of installation.
Even the most experienced builders will not generally make a perfectly straight and mm- perfect aperture for your windows and doors. The windows and doors will therefore be made to allow around a 10mm gap all around between the frame and the brickwork. It is a good idea to ensure that this gap is properly filled and sealed to avoid the possibility of draughts. Many installers will trim over the gap to leave it looking tidy, but not all will fill the gap adequately first.
When a window or door is installed in a new build situation, it will usually be secured into the brickwork before the render and plaster are applied. This allows the builders to plaster up to the window, ensuring the gap between outer frame and the brickwork is covered and weather-tight.
When replacing an existing window or door, the installers will often not be able to avoid damaging the plaster or render when removing the old frame. The more reputable installers will ensure that the render is repaired and will use some cover strips that match the window/ door frame to trim over any damage to the plaster inside.
There are two widely recognised ways of securing the window or door to the surrounding wall. Probably the most common method is to screw through the outer frame of the window or door into the brickwork using long galvanised steel screws. The other option is to use what are known as lug fixings whereby a metal plate is secured to the outer frame and protrudes into the house. The protruding section is then secured into the wall. This method is most commonly found in new build where the lug fixing is subsequently covered by plaster. It is not so suitable for the replacements market due to the damage it would do to the decor.
Doors (and to a lesser extent windows) can be quite big and heavy. This weight is obviously supported by the hinges when the door is opened but there is quite a lot of weight that needs to be supported. If the door is not installed properly it may ‘drop’ over time so that the door snags on the frame and can become difficult to close and to lock.
Toe and heeling is a process whereby the glass is braced in the frame diagonally using packers. This keeps the door frame square and if the door is ‘toe and heeled’ correctly, it should never drop.