Termites in Window Frames: Early Signs Before the Frame Fails

Wooden window frames are embedded in walls, often near damp sills and external surfaces. Termites that reach the wall can move straight into the frame. Because most of the damage happens inside the wood, a frame can look fine while being badly weakened.

This guide lists the early signs and what to do.

The short answer

Early signs of termites in window frames include mud tubes at the frame edges or on the wall, bubbling or peeling paint, a hollow sound when you tap the wood, tiny holes or fine dust, windows that stick or no longer fit, soft wood at the lower corners and discarded wings on the sill. If you find any of these, have the frame and the surrounding wall inspected, because the colony is often in the wall or soil rather than only in the frame.

Why window frames are at risk

• They are fixed into walls that may be damp.
• Rain and condensation affect sills.
• Gaps between frame and wall provide entry.
• Wood is often untreated, particularly in older homes.

Early signs

1. Mud tubes: On the frame edge, sill or the wall around it.
2. Blistered paint or varnish: Moisture and activity beneath.
3. Hollow sound: Tap along the frame.
4. Soft wood: Especially at the bottom corners.
5. Small holes or frass: Near joints.
6. Sticking windows: Frames distort as wood is eaten or swells.
7. Wings: Near the window after a swarm.

How to inspect

• Check the bottom corners and the sill first.
• Run a screwdriver tip lightly along the wood to test for softness.
• Look along the gap between frame and wall.
• Inspect from both inside and outside.

What to do

1. Photograph signs.
2. Do not paint over the damage.
3. Book a professional inspection of the frame and wall.
4. Have the source treated and the wood treated or replaced.

Prevention

• Use treated or durable timber, or alternatives such as aluminium or uPVC for new frames.
• Seal the gap between frame and wall.
• Maintain paint and varnish.
• Fix leaks and drainage around windows.
• Inspect each year.

When to call a professional

Do not wait for the frame to fail. A termite specialist can find whether the problem is local or part of a wider infestation.

Frequently asked questions

Can a window frame be saved?

If damage is limited, treatment may save it. Severe damage needs replacement.

Do metal frames avoid the problem?

Termites do not eat metal or uPVC, but they can still enter via the wall and attack nearby wood.

Is a frame near the ground at higher risk?

Yes, ground-floor windows are generally more exposed.

Why does my window stick?

It can be humidity or distortion from termite damage. Check for other signs.

This guide is part of IPest's complete resource on termite control. For identification help, prevention and treatment options, see our full termite treatment guide for Bangalore.