Maintaining the Beauty: Caring for Repaired Old Sash Windows

By Swindon Link - 22 September 2023

Home and Garden

Original sash windows can add great character and charm to a home, but repairing old sash windows properly is key to preserving their beauty and function.

Without proper care, after repairs are made, old timber windows can quickly lose their aesthetic appeal and performance.


Follow these tips to keep your renovated sash windows looking and working their best for years to come.

Regular maintenance is key for any timber frame structures

Original windows require some regular basic maintenance to keep them functioning and prevent rotten wood.

- Wipe down the sashes, jambs, and sills monthly using a soft cloth to remove any built-up dirt, debris, or grime. This helps prevent the moving parts from binding and keeps the wood clean.

- Check the sash cords and any pulleys or counterweights yearly. Replace any worn or frayed cords to prevent the sashes from falling out of alignment. Lubricate pulleys/weights if needed.

- Lubricate the channels where the sashes slide up and down by applying a thin coat of wax or silicone spray twice a year. Also, keep ironmongery in check. This prevents sticking and allows the sashes to operate smoothly.

- Inspect the glazing putty and paint around the window panes every 2-3 years. Repaint or reglaze as needed to seal any cracks and prevent moisture damage or drafts. Spot paint any flaking paint.

- Consider having a professional conduct a more thorough maintenance check annually. They can identify any hidden wear, damage, or needed repairs.

- Replace any missing or severely deteriorated glazing, sash cords, broken pulley mechanisms, cracked wood, etc. right away before further damage occurs.


Performing regular light maintenance and inspection will go a long way in preserving your antique sash windows and keeping them functioning properly for many more years. Don't let small issues go unaddressed.

Keep Moisture and Drafts Out - Draught-proofing and putty repair

Old sash windows can be prone to air leaks and moisture intrusion if not properly sealed. Take steps to keep the elements out.

- Caulk inside and out with a high-quality paintable caulk where the sashes meet the rails and jambs. This seals the joints between the moving parts.

- Check the exterior caulking and glazing putty around the window panes for any gaps or cracks annually. Recaulk or reglaze as needed to prevent water from seeping in.

- Install weatherstripping along the edges of the sashes if it is absent which is common in traditional sash windows. Draught-proofing will make your historic windows more thermal efficient.

- Make sure the upper and lower sashes align correctly when closed. If misaligned, adjust the sash cords so the halves meet evenly. Poor closure can lead to air and water infiltration.

- For highly exposed or leaky windows, consider installing storm windows over the exterior to create an additional weather barrier.

- If condensation or frost forms between the interior glass panes, the seal may be broken. Have a professional reglaze the window to prevent moisture damage.


Taking proper sealing measures will extend the life of old sash windows by protecting them from deteriorating due to dampness, rot, and condensation. Maintain caulking and weatherstripping regularly.


Protect with paint

Frequent repainting of period windows is key to protecting the wood and keeping them looking their best.

- Sand, prime, and repaint the exterior wood sashes, rails, and trim every 5-7 years using high-quality oil-based or water-based paints like Zinsser or International. This protects from moisture damage.

- Any time you notice cracking, flaking, or peeling paint on wooden windows, prepare the surface and spot-paint those areas immediately to prevent moisture intrusion into the wood.

- Consider hiring professional painters and decorators for exterior painting if the windows are highly elevated. Proper surface prep and application are key.

- Paint the sash channels only with silicone spray, not brush paint, to allow free movement of the sashes.

- Clean surfaces thoroughly before painting, and sand glossy surfaces to degloss for proper adhesion.

- Dispose of paint scraps properly. Never dump liquid paints down drains.


With proper prep and the use of high-quality paints made for wood trim, the freshly painted windows will look beautiful and be protected from the elements for years before needing to be redone.


Know When to Seek Professional Help

While regular maintenance can be done yourself, some issues with old sash windows should be handled by a professional to avoid damage or injury.

- If the sashes are sticking badly or have been painted shut, hire a contractor to strip the paint and properly lubricate and adjust the windows. Attempting to force stuck windows open can cause breakage.

- If the sash cords have broken or the pulley mechanisms or counterweights are damaged, the sash window specialist can safely rest and balance the sashes.

- For any signs of exterior water damage, window sill rot, leaks around the frames, or major gaps in caulking, contact a sash window specialist. Left unaddressed, moisture damage can be severe.

- If multiple panes of glass have cracks or missing glazing putty that needs replacement, it's best to have a professional reglaze the windows properly.

- If the sill or lower rails are deteriorated, a contractor can repair or replace just those sections rather than the entire window.

- For upper story windows, hire a qualified sash repair company rather than attempting dangerous repairs yourself.


Seeking professional help at the first signs of needed major repair will keep your historic sash windows operational and preserved. Don't let small problems turn into bigger, more costly fixes.

Proper care will keep old sash windows working smoothly and looking beautiful for decades to come. With a little regular effort, you can maintain their charm and functionality.

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