The Ultimate Guide to Restoring and Repairing Casement Windows

Casement windows are a popular choice for homeowners due to their versatility, energy efficiency, and aesthetics. However, like any other window type, they can suffer from wear and tear over time. In this comprehensive guide, we'll explore the ins and outs of casement window repair, including how to identify common issues, the tools and materials you'll need, and step-by-step instructions for fixing various problems. By the end of this post, you'll be well-equipped to restore your casement windows to their former glory.

Table of Contents

1. [Identifying Common Casement Window Issues](identifying-common-casement-window-issues)

2. [Tools and Materials for Casement Window Repair](tools-and-materials-for-casement-window-repair)

3. [Step-by-Step Guide to Repairing Casement Windows](step-by-step-guide-to-repairing-casement-windows)

[Fixing a Broken Crank Handle](fixing-a-broken-crank-handle)

[Replacing a Damaged Sash](replacing-a-damaged-sash)

[Repairing a Rotted Window Frame](repairing-a-rotted-window-frame)

[Sealing Drafty Windows](sealing-drafty-windows)

[Upgrading Window Hardware](upgrading-window-hardware)

4. [Maintaining Your Casement Windows](maintaining-your-casement-windows)

Identifying Common Casement Window Issues

The first step in repairing your casement windows is to identify the specific problem you're facing. Some common issues include:

Broken or worn-out crank handles

Damaged or warped sashes

Rotted or deteriorated window frames

Drafty windows due to gaps in the seal

Malfunctioning or outdated hardware

Once you've determined the issue, you can gather the necessary tools and materials and proceed with the appropriate repair.

Tools and Materials for Casement Window Repair

Before diving into the repair process, make sure you have the following tools and materials on hand:



Pry bar

Utility knife

Tape measure

Wood chisel

Wood filler or epoxy


Paint or wood stain

Caulk and caulk gun


Replacement parts (e.g., crank handles, sashes, or hardware)

Step-by-Step Guide to Repairing Casement Windows

Fixing a Broken Crank Handle

1. Remove the old crank handle by unscrewing it from the window operator.

2. Measure the spindle's length and diameter to ensure you purchase the correct replacement handle.

3. Attach the new handle by aligning it with the spindle and securing it with the provided screws.

Replacing a Damaged Sash

1. Carefully remove the sash by detaching it from the hinges and lifting it out of the frame.

2. Measure the dimensions of the old sash to order a suitable replacement.

3. Install the new sash by attaching it to the hinges and ensuring it opens and closes smoothly.

Repairing a Rotted Window Frame

1. Use a utility knife or chisel to remove the rotted wood from the frame.

2. Fill the void with wood filler or epoxy, shaping it to match the surrounding frame.

3. Allow the filler to dry, then sand it smooth and paint or stain it to match the rest of the frame.

Sealing Drafty Windows

1. Inspect the window for gaps or cracks in the seal and apply caulk as needed.

2. Replace worn or damaged weatherstripping to ensure a tight seal when the window is closed.

3. Consider adding window film or insulating curtains to further improve energy efficiency.

Upgrading Window Hardware

1. Remove the old hardware, such as locks, latches, or hinges, by unscrewing it from the window frame.

2. Measure the dimensions and note the style of the existing hardware to purchase suitable replacements.

3. Install the new hardware, ensuring it functions properly and enhances the window's appearance and security.

Maintaining Your Casement Windows

Regular maintenance is key to prolonging the life of your casement windows and preventing the need for future repairs. Here are some tips for keeping your windows in top shape:

Clean the window tracks and lubricate the moving parts to ensure smooth operation.

Inspect the window frame and sash for signs of wear or damage, addressing issues promptly.

Check the seal and weatherstripping for gaps or wear, replacing as needed.

Keep the window hardware clean and functional, tightening screws and replacing broken parts as necessary.

Repaint or stain the window frame periodically to protect the wood from moisture and UV damage.

Armed with this knowledge, you're now ready to tackle any casement window repair project with confidence. Remember, regular maintenance and prompt attention to issues will help keep your windows functioning smoothly and looking beautiful for years to come.

Casement Window


Casement windows are the most common style of window. They feature hinged panels that swing open and closed. Casement windows are available in single panels or multiple panels. The direction a door swings, either to the right or the left, is called the handing. In addition to handing, window are identified as either inswing or outswing depending on whether they open into the house or towards the outside.


Our team of experts will work with you to develop a bespoke plan that fits your needs. We take a holistic approach to the planning process, combining our technical expertise with our knowledge of customer requirements and project constraints.


Freedom to dream "truly custom-made"

Doorwin provides one-stop solution for professional windows doors manufacturer and installation. We have been serving customers with our high quality and branded products in United States, Asia and worldwide.


This newly built private house is in Sydney, Australia. The area occupied by the fenestration system in our scheduled design drawings was up to more than 110 square meters. A wide range of design details made the perfect mix of modern aesthetics and traditional sophistication, the simulated vertical hung windows with tilt & turn opening systems in this home are absolutely breathtaking. SDLS (Simulated Divided Lites with Spacer Bar) brings some historical vintage feeling to the whole building without losing any energy saving performance. Long narrow fixed windows creating larger-than-life expenses, coupled with German high-end systems made this project stand out from the rest.

Simulated Hung Window with Tilt & Turn Openings

The client's idea was to maintain a certain vintage feel, and our aim was to meet the energy efficiency needs and standards of modern houses as much as possible while maintaining a retro design. Doorwin’s 61S simulated hung windows with tilt & turn openings is a respectful modernization of a classic architectural masterwork.

Why choose the tilt and turn opening method?

Because it generally has better air seals than sliding, single hung, or double hung window frames. Tilt and turn windows form a complete seal when fully closed, this means they are less prone to water leakage, and cold draughts and you’ll keep more of your heating indoors where it belongs. They can be opened in the upper tilt way to ventilate at a minimum opening status and are easy to clean outside of the glass; when there’s a good day, they can be opened as normal inward casement windows.

Large Energy Efficient Fixed Windows

Our well-crafted bespoke systems enhance the functionality and panoramic view of this modern house.

Huge, fixed glass walls up to seven meters long and two meters high bring great lighting and open views, making it really refreshing to the mind. Five meters high long narrow windows give the whole building a contemporary aesthetic.

Every window’s placement and shape not only add to the uniqueness of this home but also provide a more energy-saving ability for the owners.

Doorwin energy-efficient integrated glazing units feature double-pane glass, warm-edge spacers, argon gas fill, Low-E coatings, and fully tempered glass, they can not only create a comfortable and natural indoor environment but also save electricity bills and heating bills of more than 100 USD for the owner, it’s a real bargain compared to choosing a regular glazing set.

Custom Designed Thermal Break Aluminum Entry Door

Aluminum Door offered an air of uniqueness and elegance to a home. With their luxurious patterns and beautiful finishes, it provides this house with a bounty of aesthetics and security. Aluminum entry doors allow you to resist any weather extremes, corrosion, and pests. So aluminum is one of the most resilient and durable materials you can select for front doors considering the price/performance ratio.

With pieces of double panes, and Low-E tempered glass. The door provides a good insulation performance.

Custom Designed Grilles and Transom

Divided lite windows and doors offer unique architectural solutions for buildings without compromising energy efficiency or aesthetics. Doorwin provides multiple muntin and glass options to customize your divided lite windows and doors. Further customization is available with a variety of colors and materials, creating an infinite number of design combinations to best suit your style.

In this project, we use SDLS (simulated divided lites with spacer bars), these bars permanently adhere to both sides of the glass, and spacer bars are installed between the glass, this is the most energy-efficient way to create the look of classical décor grilles. The windows in the bathroom bedroom and study have an Arch Transom Design, making these rooms, which are often used by the owner, have some traditional aesthetics.

BTW, Doorwin offers free design assistance, so if you need a custom design like this one, contact us right away and we will provide you with the most aesthetically and functionally pleasing design solution.

German Imported Hardware System

For windows and doors, hardware is as important as the engine is to the car. The continuous technological innovation of the European hardware industry has strongly promoted the performance improvement and functional innovation of windows and doors. In this project, Doorwin uses Hoppe™ multi-point locks, hinges, and handles from Germany.

Multi-point lock systems provide not only the burglar-resistance but also a tighter compression seam, making the window keeps good energy-efficient performance. Together with Technoform Bautec’s insulation edge bond and sealant strips, these make up our products' top insulation and energy-saving performance.

Save Your Money On Installation Costs

We have several international patents to reduce clients’ labor costs, such as our unique flanges and assembly type tubular design, which is different from the other products on the market. What sets us apart among Chinese counterpart is that all our products are equipped with nail fin structures for quick and easy installation. Labor costs during installation may exceed of the window and door price, therefore, our exclusive patent allows users to not only get a significant increase in installation efficiency, but also greatly reduce the labor cost of window and door installation. A cost that may bring you unexpected savings that far exceed the price difference you may care about now.

Free Design Assistance

With our own expertise, we provided the no-cost design development and contract documentation with CAD & BIM drawings, including elevation, details about the project, and installation help.

Before production, we will provide accurate sample drawings, which will clearly show the cross-sectional pattern, size, opening method and direction, pattern of the warm spacer, and the installation nodes. We will not go into production until you have signed off on the drawing to ensure that you receive a final product that meets the exact requirements of your project.

About Doorwin

Doorwin's professional packing system guarantees all products are delivered safely and without any damage. We apply a four-point packing system. Firstly, adhesive plastic film is applied on interior wood frames and exterior aluminum frames to avoid scratches on the surface. Then, a paper board is applied after we apply air bubble film surrounding the whole windows/ doors to avoid any destruction or clash. Lastly, we place them into a durable non-fumigation plywood crate to avoid any possible damage during transportation.

With years of experience shipping our products worldwide, we could guarantee to ship our products to their final destinations intact and without any damage.

About Doorwin Factories

Doorwin is one of the most professional window & door manufacturers are known for its great customized products. In Doorwin, a variety of colors, styles, and sizes of products are available to meet the client’s unique requirements. We own three ISO9000-certified modern factories in China. With a factory area of 20,000 m2 and a production capacity of 100,000 m2 per year. Doorwin Group has the scale to ensure timely delivery and the flexibility to reduce manufacturing lead times to as short as 18 days.