Box Sash Windows: Things You Need to Know When Repairing or Upgrading

September 19th, 2017

Even though box sash windows are usually from buildings or houses built in the 18th or 19th century, there is no truth to the perception that they are not replaceable or salvageable. In fact, they can be salvaged intact and restored in excellent condition to give your period house a complete look for a long time. You only need to look for a window manufacturer with experience in dealing with sash window renovations.

Photo by Florian Pérennès on Unsplash

According to research published by The Building Conservation Directory in 2006, as much as 95% of timber in an original window can be retained when it comes to box sash window repairs. The rotten timbers are usually routed and repaired using a synthetic wood repair system. This is because most windows that are considered beyond repair usually only have superficial deterioration. Once they have been overhauled, the sash windows are back to its original beauty and can continue to provide service for a long time.

If you are in need of repairing or upgrading your box sash windows, here are some of the things that you need to keep in mind:

Box sash window repairs are not “quick-fix”.

Anyone who tells you otherwise is not being honest. No, you can’t rely on those cheap solutions when it comes to this kind of window repair. You have to understand that this repair involves a craftsman-driven process of restoring a window from a period building so that it will look good and work as intended. The condition of the windows differs from each other even when they are from the same property and an expert survey will be necessary to itemise the scope and extent of restoration needed.

Common causes of sash window problems.

Another thing that you need to know before seeking out the help of a window restoration company is the cause of your window problems. Most defects, especially on very old windows, will be apparent upon close visual inspection. However, timber decay is not as easy as that.

Check your windows for any musty smell coming from inside the weight box. This is a sign that the timber is damp inside and is probably starting to decay. You can open the weight box pocket covers to check and confirm if you suspect timber decay. Examine the condition of the weights and ensure that it is free of debris.

On the other hand, if you suspect that you have a rotten windowsill, you can test the timber using a penknife. If your timber is in good condition, it will withstand the blade. To check if the shutters are okay you can check for dampness in the plaster or wood in the window case.

Another way to check if your sash windows are working properly is by opening the fasteners and other locking devices; sliding for the full length in each case. Any stiffness or resistance is a sign of sashes dropping out of the control of your window’s counterbalancing weights. Sometimes, however, stiffness can be caused by paint that makes the sashes to stick together.

What can you add to upgrade your sash windows?

Even if your windows do not need overhauling you can always upgrade them to maximize lifespan as well as improve your home energy efficiency. Your options include repairing or adding shutters, fitting draught proofing and adding secondary glazing.

Closing internal shutters can help reduce heat loss from sash and case windows. You can have wooden shutters installed along with your sash windows to improve energy efficiency and security in your building or home.

Photo by psaudio on Pixabay

When you have draughty sash or case windows, draught proofing is a good and cheap solution. There are several systems available for you to choose from and some will even make it easier for you to slide the windows up and down. Draught proofing is also a cost-effective way of reducing dust ingress, reducing outside noise and improving comfort level for people living in your house. Just keep in mind that you will need permission for work to draught-proof historic windows.

Lastly, you can add secondary glazing to help make your box sash windows more energy-efficient. These can be fitted internally using either side hung glazing, vertically sliding windows or horizontally sliding windows. Just like draught-proofing, you also reduce heat loss, soundproof and reduce dust ingress when you add secondary glazing to your windows. Just make sure to get permission from your planning authority before starting work.

Box sash window repairs reminders.

You have to keep in mind that getting help from a competent joiner is the most important part when repairing or upgrading your box sash windows. Remember that sash windows, especially those from period buildings, need careful craftsmanship and only experienced joiner can do that. Also, don’t forget to get the necessary permits before starting any work.

Need help with restoring or replacing your box sash windows? Hugo Carter can help! Check out our sash windows offers and talk to us about your needs. Go to our Contact Us page or simply dial our numbers and we’ll be glad to assist you with your enquiries.

Recent Posts

Download our noise reduction brochure

To learn more about The Science of Silence, please download our brochure.

Download now