Window Frame Repairs

Window frame repairs: what to know

Before starting any repairs, thoroughly assess the window frame to determine the extent and type of damage. If it’s cracked, fill it with wood filler. However, if it’s rotting, cut out all the decayed wood and apply a wood hardener. Next, fill the remaining void with wood filler or epoxy putty and sand smooth.

There are many more repairs your window frame might need, including fixing warped frames and tightening loose joints.  

In this article, we will break down the different types of damage that can affect your window frame and how to tackle them step by step.

Can you repair a window frame?

You can repair your window frame if the damage is minor. For instance, minor wood rot can be patched with wood filler, cracks can be sealed with caulk, loose screws can be tightened, and chipped paint can be stripped, sanded, and repainted. However, severely damaged window frames might need a complete replacement.

Step 1: Assess the damage

Before you start any repairs, thoroughly assess the damage to your window frame. Search for signs of rot, cracks, warping, or loose joints. If the wood feels soft or crumbly, you likely have rot. If it looks like the wood is cracked but not soft, you might be dealing with simple aging or impact damage. If the window frame feels unstable at the corners, it may have loose or damaged joints.

Understanding the type of damage will help you decide on the best repair method.

Step 2: Repairing rot or decay

If the window frame has rotted wood, you need to remove the damaged sections first. Scrape all the rotted material with a putty knife or chisel to prevent the rot from spreading further. 

For shallow rot, treat the remaining wood with a wood hardener. After the hardener has dried, fill the void with wood filler or epoxy putty. Once the filler has dried, sand it down so it’s smooth and flush with the rest of the frame. Lastly, apply primer, followed by paint or wood stain, to protect the wood from future moisture. 

For deeper rot, the most effective solution will be replacing large sections of the frame entirely.

Step 3: Repairing cracks

Clean the crack with a utility knife or putty knife to remove debris, dust, or loose wood. This will help the filler bond better. For small cracks, simply apply the filler into the crack and use a putty knife to smooth it over. For larger cracks, you may need to inject wood glue into the crack before clamping the frame to ensure the crack closes tightly. 

Once the filler or glue has dried, sand the area smoothly to blend with the rest of the frame. Finally, apply a coat of paint or finish to match the surrounding woodwork.

Step 4: Fixing warped frames

A warped window frame can be trickier to repair, especially if the warping is severe. If the frame is only slightly bowed, it might be possible to straighten it using heat from a steam iron or moisture from a hot towel. However, this approach requires careful attention, as too much heat or moisture can damage the wood further. 

If the warping is beyond what can be corrected with heat, you may need to replace the warped sections entirely. Another option is reinforcing the frame with metal braces or wood splints to help keep it square.

Step 5: Repairing loose joints

If the joints of your window frame are loose but the wood is still in good shape, you can simply re-glue the joint with a strong wood glue like Titebond, then clamp the pieces together tightly. Make sure the frame is properly aligned while the glue sets. 

Depending on the type of joint, it’s best to reinforce the repair with small screws or nails to provide added strength. After the glue has dried, sand the area smooth and finish with paint or stain to match the rest of the frame.

Step 6: Sealing gaps and drafts

Sometimes, gaps around a window frame can cause drafts or leaks. If you find gaps, the first step is to remove any old caulk with a utility knife or putty knife. Once the old material is removed, clean the surfaces where new caulk will be applied. 

Then, apply a fresh bead of high-quality silicone or acrylic caulk along the edges of the frame. Use a caulk smoothing tool or your finger to smooth it and ensure it forms a tight seal. Finally, wipe away excess caulk and let it dry before closing the window.

Repairing rotted wooden window frames

Interior wooden window frames

Unlike the widow frame outside the home, the interior wooden window frame suffers mostly cosmetic damages (scratches, small cracks, peeling paint) rather than moisture-related issues. 

Start by dusting and wiping the window frame with a damp cloth. Then, fill small cracks, chips, and holes with wood filler only, as the frame is not exposed to harsh weather or moisture changes. Next, tighten or replace loose screws and hinges, and use interior-grade paint for refinishing the wood.

Exterior wooden window frames

Outdoor windows are more likely to be damaged due to water rot, UV degradation of paint, and warping from sun and moisture. The repair process starts with thoroughly cleaning the window sills, track, and frame to remove dirt, mildew, moss, and water stains. Sometimes, pressure washing or scrubbing with a mild cleaning solution is needed to clean the frame thoroughly. 

Next, fill small cracks, chips, and holes with an epoxy wood filler, which is better suited for outdoor conditions. Repainting or refinishing exterior wooden frames requires exterior-grade paint or stain designed to withstand sun, rain, and temperature fluctuations. Lastly, seal the gaps around and between the frame and wall with a high-quality, weather-resistant caulk.

Vinyl window frame repair

Over time, plastic components inside a vinyl window frame can become brittle due to UV exposure or normal wear and tear, causing them to break or crack. Poor manufacturing or material defects can also make the ​​reinforcing insert or locking mechanism more prone to breaking.

If the part is a reinforcing insert, you can replace it with a new piece of plastic or vinyl. Sometimes, this can be done using vinyl adhesive or ordering a replacement part from the manufacturer. On the other hand, if it's part of the locking mechanism, you need to replace the lock or latch.

Cost to repair a window frame

The cost to repair a window frame depends on the window material, the extent of the damage, and the type of repair required. Wooden window frames are the cheapest to repair, typically costing between $175 and $300 for labor and materials. 

Aluminum window frames fall in the middle range, with repair costs generally between $250 and $500. Vinyl and fiberglass frames are costly to repair, ranging from $300 to $600. Composite frames are the most expensive to repair, between $400 and $650.

Historic window restoration and repairs

When repairing historic window frames, the goal is to preserve as much of the original material as possible. The first step is to assess the damage carefully. Common issues with historic windows include wood rot, broken glass, loose or missing parts, deteriorating glazing, and paint chipping. The condition of the frame and sash also needs to be checked for structural integrity and the window's ability to open and close properly.

If only a small area of the frame is affected, it can be repaired by strengthening the wood with a special epoxy wood resin. For larger areas of damage, you may need to replace sections of the wood rather than the entire frame. However, carefully match the wood’s grain and color to maintain the window’s historical appearance.

If the glass is cracked or missing, replace it with period-appropriate glass. For instance, use wavy glass to match the look of the original panes. 

Lastly, historic windows often use putty glazing to secure the glass panes. If this has deteriorated over time, carefully remove the old putty and apply the new glazing compound.

Repairing your window frames

Regular maintenance of your window frames is key to preventing bigger damage. 

Some maintenance tips you can implement are: inspect window frames annually for signs of moisture, rot, or cracks. Reapply caulk or weather stripping every few years to maintain airtight seals and prevent drafts. If you live in a particularly humid or rainy climate, use a moisture-resistant wood treatment to protect your frames further.

If the damage to your window frame is extensive, a DIY approach can be time-consuming, costlier, and lead to worse damage. Instead, you can hire your local handyman independently or use a professional platform like Angi. 

We recommend Angi because it offers a large database of vetted and skilled handymen and contractors. The platform also features reviews and ratings from real customers, giving you valuable insights into the quality of work you can expect.