Understanding how to repair double-hung sash windows is crucial when you’re faced with issues that disrupt their functionality.

If windows are working properly, it’s easy to take them for granted, but when they’re broken, we notice. Whether it’s a faulty balance system or a rotten sash frame, often, double-hung sash windows can be repaired rather than replaced, which saves both time and money and restores your window to working order.

In older homes with original wood windows, repairing rather than replacing a double-hung sash window is often the ideal solution because it’s difficult to find a replacement for original wood windows. Many manufacturers have discontinued older styles and many of today’s windows favor other materials such as vinyl, aluminum, or composite. If you replace just one window, it may stand out as different from the others and detract from the home’s aesthetics.

Repairs can often be done with a few replacement parts and common household tools. To show you how to repair double-hung sash windows, we’ll first take a look at the different parts of a double-hung window that could fail and then show you how to replace them.

Double Hung Window Parts

A double-hung window actually contains more parts than it may seem at first glance. Any of these parts could fail at some point, and replacing the part will save the time and cost of replacing the entire window. 

• Frame: the outer frame of the window that holds all of the other parts and is installed into the wall of the structure
• Head: the upper horizontal part of the frame
• Casing: the vertical sides of the window frame
• Stool – the protruding ledge on the bottom of the window

Note: If any of these parts are damaged, you may need to replace the entire window.

• Sash: the operable part of the window that contains the glass and grilles. In a double-hung window, there are two sashes.
• Glass: the glass can be one pane or multiple panes held together with the grille system. Modern windows typically use one pane of glass with decorative grilles but original windows may use multiple panes
• Grilles: the small pieces of wood or other material that either hold the glass panes in place or are glued to the surface of the glass as a decorative element
• Rail: the top of a sash frame
• Sash lock: the locking mechanism located on the sash that locks it in a closed position
• Lift: the piece of hardware that aids in opening and closing the sash
• Jamb liner: the liner that is attached to the frame to conceal the balance mechanism

Balance: located in the jamb liner or in the frame itself, the balance allows the upper sash to be lowered and the lower sash to be raised and held in the desired position. Common types of balances are cord and weight, spiral, block and tackle, and constant force.

Common Problems with Double Hung Windows and How to Repair Them

The Problem: The Double Hung Window Won’t Stay Open

If your double-hung window sash won’t stay open, gets stuck or is difficult to slide up and down, you will likely need to replace the balance.

The Solution: Replace the Balance

Replacing the balance is easier than it sounds, and a double-hung balance kit makes it even easier. 

1. Determine the type of balance you have and order a replacement.
2. Remove each sash by raising the lower sash lowering the upper sash and tilting it towards you and then tilting it at an angle and removing the tilt pins from the frame. Set each sash aside.
3. Remove the jamb liner by releasing the internal flanges and sliding the liner out of the frame.
4. Place the new jamb liner (which contains the replacement block and tackle balance) into the frame and tuck the flanges in on both sides. If using a different type of balance, attach it to the frame as per its instructions. 
5. Replace the sashes — the tilt pins will attach the sash to the balance to allow the window to be raised and lowered.
6. Test the window to make sure the sash moves freely and stops where it should.

The Problem: The Double Hung Window Sash or Glass Is Damaged

If the window sash is damaged or rotted or the glass is cracked, a full replacement sash is likely the solution. If the sash is made of wood, it can be difficult to find a replacement sash that matches the original because many manufacturers have discontinued certain models over the years. Fortunately, here at Fenster, we offer Quiksash replacement sash kits that come with the following:

• Upper/lower sash set
• Universal double-hung design 
• Jamb liner kit with heavy-duty balances
• Sash locks and bulb seals applied

You can also order a brand-specific replacement if needed.

The Solution: Replace the Sash

To replace the sash, follow these steps:

1. Measure the double-hung windows to determine the correct size.
2. Remove the existing upper and lower sashes by tilting them towards you and turning them at an angle to release them from the frame.
3. Remove the jamb liner by using a putty knife to remove the flanges from the frame.
4. Install the new jamb liner by putting it in place and tucking the flanges into the frame.
5. Install the new sashes by placing the tilt pins in the new jamb liner and sliding the sash into place.

The Problem: The Hardware Is Broken

Double-hung sash windows include a few pieces of hardware that are necessary to ensure safety and smooth operation. The sash lock maintains safety while the lift allows you to open and close the window.

The Solution: Replace the Hardware

If you’re replacing the entire sash, our Quiksash kit comes with pre-installed hardware, but if you just need to replace the sash lock or lift, you can find them at your local hardware store.

1. Remove the defective piece of hardware.
2. Replace it with a new lock or lift.

Fenster Provides Replacement Replica Sashes to Keep Your Windows in Working Order

Fenster engineers custom sashes that replicate existing brands and models. Because we aren’t affiliated with any brands, our products are after-market replications of the original and are designed to closely resemble the original. This allows you to replace individual windows rather than replace all of them or deal with one window that isn’t like the others.

Whether you need to replace the entire sash, the balance, or the hardware, Fenster has you covered.

Contact the experts at Fenster today or take a look at our video tutorials and checklists to get started on your project.