Mistakes When Renovating Sash Windows

One of the most common mistakes when renovating a sash window

Occasionally we come across some funny mistakes when a sash window has been repaired. Well, they start off not so funny!

One of the most important things when renovating a sash window is to get the balance right. When you raise or lower the sashes they should stay where you want them. This is achieved by making sure the balance weights (hidden in the box frame) equal the weight of the sashes themselves.

Over time the sash weight may change, mainly when glass has had to be changed. So it’s important to check and, more often than not, to increase the corresponding balance weight.

This is done properly by using special lead add-weights which have a hole through them for the cord to pass, and which sit on top of the existing weights.

Now and again we meet a window where the tradesman hasn’t got a supply of add-weights so instead takes a roll of roofing lead and wraps it around the cord!

Now, lead is a soft metal. So over time as the weights hit the side of the box, each other or a stray nail the lead gets bent and will eventually get stuck in the box seizing the sashes good and proper. At which point the customer usually just screws the affected sash shut.

It tends to manifest itself when you try to put the new cord and weights in and find there is a lump of lead stuck inside the box, usually high up near the pulley. Half an hour later, and after much cursing, it’s freed up and drops to the bottom for retrieval (and disposal).

So next time someone says they are adding balance weight just take a look and see what they are using.

How not to add balance weights