In terms of replacing your double glazed windows, there tend to be two meanings for DIY. For some people it means buying the replacement units and installing them yourself, for others it means buying the units, but hiring a local tradesman to install them for you. Either option will save you money compared to ordering and installing via a glazing company, but although installation is a pretty straightforward task, it must be done properly to avoid future problems.
The most important part of this project will be the measurement. The glass is cut to fit the frame, so if you get the frame size right, the glass will fit it properly. DIY double glazed units are delivered in 3 parts – the frame, the glass and the cill. Often the cill is supplied slightly longer than needed. This is because some cills extend past the window. You can cut it to size once you have received it.
Check with your local building authority in terms of regulations covering windows. You may find that you need a specific type of safety glass for certain windows, or that there are restrictions on the type of frames you use. There may also be regulations with regard to ventilation in double glazed units, and it would be wise to make sure the unit you order complies with all these requirements.
Before you remove the existing window, check carefully that you have ordered and received the correct size – there is nothing worse than breaking out your existing window only to discover that you have the wrong size unit to replace it with – and may have to spend a day or two with an open window while you change the new one to the correct size. When removing the existing window, do so as carefully as possible. The less damage you do to the surrounding walls, the less work you will have installing the new unit. You will also have to be careful that you do not damage damp proof courses, particularly the vertical ones that usually run below windows. Wear safety goggles and gloves when removing the glass, and keep children and pets away from the area.
Although you do not need specialised tools to fit double glazed units, you will need a saw to cut out the old frame, and a finer toothed saw to cut the cills to size. You will also need a claw hammer, a spirit level, a screwdriver and an electric drill. To remove the glazing beads you will need a paint scraper, and you’ll need a rubber mallet to refit them. Silicone sealant and the skeleton gun used to apply it will be needed as well. In most cases you will work on a ladder.
DIY double glazed units will come with detailed installation instructions, or you can find them online. They should include all the fixings you need to install the unit, as well as glazing packers. Packers are used to prevent moisture build up which leads to the condensation problem so many double glazed units suffer from. The packers should raise the window unit above the frame so it does not rest directly on it, and both panes of glass should be supported by the packers. When you are installing the unit make sure you don’t put the packers over the drainage holes.
Most reputable manufacturers will offer a guarantee on their DIY double glazed units – some up to as much as 10 years. If you are in doubt as to whether you can install the unit yourself, it may be worth the additional expense to have an expert install them. Most condensation problems are due to poor installation.
