Do you have sash windows? If so, you might find it useful to know when they need service or repair. Here are five ways to tell…
1. The joints on your lower sashes
When considering the structural condition of sash windows, the first place to look is outside. Almost all wear and tare occurs externally. The most common points on a window to fail are the joints of the lower sash. These are mortice and tenoned together and bound by wedging and epoxy glue. This is a joint that can hold for more than a hundred years in UK weather conditions but will eventually fail. This occurs when paint begins to peel away and moisture penetrates under the rail. This swells the stile and makes it pull away from the lower rail. Also, the moisture helps to deteriorate the joint of glue and timber so it’s a double effect.
Fortunately there’s a simple solution to this. Make sure you keep the lower rail of your sash well painted to moisture can’t penetrate. Maintenance before repairs will save a fortune. The cost of replacing a lower rail in this situation is around £400 as the window needs removing, then the rail repairing, and then the sash needs refitting with new sash cords which is a lengthy process.
2. The sash cords are beginning to fray
Sash cords begin to fray after twenty years. This assumes they are high quality nylon core, lower quality cloth only cords might only last ten years. The problem with a sash cord that frays is the possibility of breaking panes of glass when the window is open. You open the window for some fresh air and then walk away, only to hear a loud crash and that dreaded broken glass noise. As the sash falls it lands on one edge first causing the shape to distort as timber has a lot of flexibility. Unfortunately glass doesn’t and this pushes the edge of the glass into the pins that hold it in or frame of the sash.
On the other hand if the glass was installed correctly with a 3mm gap around the edges and the putty holding glass to sash firmly then you might be lucky, the glass might not break and you’ll only need to replace the sash cords. Most sash window repair companies will offer this service for around £200. Historic England offer plenty of sound advice in their PDF with regards to traditional window care.
3. Sash window sill starts to look rotten
When sash window sills start to look weathered and rotten they can actually be replaced without replacing the window entirely. There are sash window repair specialists that can cut out the effective timber, treat the remaining section, and then splice timber back with a resin bond to ensure a lasting job. The repairs are then primed and undercoated. You might not ever realise your windows have been repaired if done properly.
4. Misted double glazed units
If you already have double glazed sash windows, which is perfectly normal since they were introduced twenty years ago, then you might be the first to have a glazing repair bill. Some sash window companies will simply remove the sash affected, replace the double glazed unit, and put the window back together. Other sash window specialists refuse to carry out these repairs and deem the window beyond economical repair, attempting to push more new windows. That’s fine if you’re happy with that, but certainly not necessary.
5. Flaking paint on the outside of your sash windows
When paint starts to flake outside its time to paint, as we mentioned in the first and third point it is the beginning of significant repairs and the basis to keeping your windows in tip top condition. If painting is kept up then you’re going to cut sash window repair bills considerably.
*This is a collaborative post.