How To Replace Glass in a Broken Window

A broken window is often one of those accidents that just can't be avoided. Children with footballs, storm damage and attempted break ins are some of the most common reasons for having to replace glass, and it’s often a job that we call in a glazier to do for us. This can be quite expensive, especially if you call someone out of hours or on a weekend. Replacing glass can be a little tricky if it’s something you have never done before, but it’s a job that most people with basic DIY skills can do with a little planning.

Emergency Repairs

If you have had storm damage or an attempted break in, you need to deal with the problem right away. If you are going to be able to get glass and do the job in the morning, all that you need to secure your home is a sheet of polythene and some tape. For longer term repairs, chipboard can be screwed or nailed into the frames until you have time to do the job properly.

Buying the Glass

The first thing that will need to be bought is glass to fit the window which is cracked or broken. Glaziers are happy to sell you glass which is cut to order if you can give them accurate measurements. Measure the size of the window carefully either in inches or in centimetres and call round a selection of local glass suppliers to get prices for the glass which you need.

If your glass has been damaged by someone kicking a ball or because someone has tried to break in, it might be worth considering safety glass or toughened glass which is less easy to break. It may be a little more expensive, but spending extra now will mean not having to replace the glass again in the future.

Tools Needed

It's worth having a good set of chisels so you're prepared

As well as the glass you have bought to fit your window, you will need some basic DIY tools and items which can be easily bought in any large DIY store and many of the larger supermarkets too. The main things you will need are gloves to protect your hands while working, safety goggles, a chisel, some putty, hammer, putty knife and paint. If you are unsure of what tools you need, ask for advice from a sales assistant in the shop.

Removing the Old Glass

The first job once you have got your new glass and gathered together all of the tools you need is to remove the old, broken glass from the window.

Put a dust sheet on the floor underneath the window to catch the glass as it falls. Using your safety gloves and wearing the goggles to protect your eyes from shards of glass, score the glass around the old putty to try to loosen it. Tap the glass carefully with your hammer and remove the pieces gently, making sure they fall onto the dust sheet.

Once as much of the old glass has been removed as possible, use your chisel or an old knife to remove all remaining glass and bits of old putty.

Putting in New Glass

Start by taking the putty out of the packaging and work it in your hands like modelling clay until it is soft and easy to mould. A little water on your hands may help if the putty is very sticky. Shape the putty into a long sausage shape around 3mm thick, and press it into the edges of the window frame to hold the new glass into place.

Once you have gone around all of the edges of the frame with the putty – paying especial attention to the corners – press the glass carefully into position. Only ever press on the edges of the glass avoiding the middle of the pane as this may cause the glass to break.

Finishing

After your glass has been put into the frame, trim off any excess putty using a special putty knife, taking care not to remove too much of the putty or damage the glass as you work. Putty can take up to two weeks to harden and dry completely, so you cannot immediately start painting and priming the frame.