Replacing sash cords in heritage windows 

Sash windows are known for their timeless elegance and functionality, especially in historic and heritage properties. However, over time, components like the sash cords can wear out or break, leading to operational issues. At Ventrolla, with over 40 years expertise in restoring heritage timber windows and doors, we understand the importance of maintaining these features. While we recommend consulting professionals for comprehensive repairs, here’s a guide for those considering a DIY approach to replacing sash cords as a temporary fix when needed. 

Understanding the role of sash cords 

Sash cords are a key component of the windows, providing a counterbalance mechanism. They connect the window sash to hidden weights within the window frame, ensuring that it continues to operate smoothly and remains balanced. When these cords break or fray, the window can become difficult to open or close, compromising both functionality and safety. 

Replacing sash cords 

Please note: this guide is just a general overview. Specific window designs may vary, and it is essential to ensure safety and accuracy during the repair process. We would strongly encourage everyone to contact a trained professional to fix any issues. 

1. Preparation 

• Tools needed: screwdrivers, utility knife, new sash cord, measuring tape, small nails or screws, hammer, and a chisel. 

• Safety first: always wear safety glasses and gloves. Ensure the work area is clear and that you have a stable platform to work from. 

2. Accessing the sash window 

• Remove interior stops: carefully pry off the interior window stops using a chisel or flat-head screwdriver. Label each piece to ensure accurate reinstallation. 

• Extract the sash: tilt the sash inwards and detach it from the window frame. If the window has been painted shut or is difficult to remove, gently score the paint seam with a utility knife to avoid damaging the wood. 

3. Removing the old cord 

• Access weight compartment: locate the access panel on the side jamb and remove it to expose the sash weights. 

• Detach weights: carefully pull out the sash weights and untie or cut the old cord. It is advisable to label each weight (e.g. ‘left’ or ‘right’) to ensure they are reinstalled correctly, as weights may vary slightly. 

4. Installing the new cord 

• Measure and cut: measure the length of the old cord and cut the new sash cord to match, adding a few extra inches to ensure a proper fit. 

• Attach to weight: thread the new cord through the top of the sash weight and secure it with a robust knot, such as an overhand or figure-eight knot. Ensure the knot is tight to prevent slipping. 

• Thread the cord: feed the other end of the cord over the pulley at the top of the window frame, allowing the weight to hang freely in its compartment. 

5. Reattaching the sash 

• Secure cord to sash: with the sash positioned near its original location, pull the cord taut and mark where it meets the sash-s cord groove or attachment point. Secure the cord using nails or screws, ensuring it’s aligned correctly for smooth operation. 

• Reinstall sash: place the sash back into the window frame, ensuring it moves freely. Reattach the interior stops, ensuring they are flush and secure. 

6. Final adjustments 

• Test operation: open and close the window several times to ensure smooth movement and proper balance. 

• Trim excess cord: if there’s any excess cord, trim it nearly to prevent interference with window operation. 

Considerations 

While DIY repairs can be fulfilling, sash window mechanisms are intricate, and improper repairs can lead to further issues. Ventrolla’s unique Perimeter Sealing System not only addresses cord replacements but also enhances energy efficiency by eliminating draughts and reducing external noise.  

Maintaining the functionality and charm of sash windows requires attention to detail and an understanding of their mechanism. Whether you choose to undertake a DIY repair or seek professional assistance, ensuring that components like sash cords are in optimal condition is crucial for the longevity and performance of your windows. For comprehensive restoration and to preserve the historical integrity of your windows, consider consulting professionals.