How hot weather can affect timber windows – and what you can do about it

When temperatures rise, it’s not just us that feel the heat. Timber windows can also respond to changes in temperature and moisture levels, particularly older sash and casement windows.

You may notice windows becoming harder to open, paint beginning to crack or flake, new gaps appearing around the frame, or a room becoming noticeably warmer than usual.

For homeowners with period or heritage properties, these changes can be frustrating, but they don’t necessarily mean your windows need replacing.

At Ventrolla, our approach is always restoration first. Every property and every window is different, so we assess the condition of the existing timber before recommending the most appropriate solution. Often, a combination of specialist repairs, draught-proofing, glazing and maintenance can significantly improve performance while retaining the original character of your home.

Why does hot weather affect timber windows?

Timber is a natural material, so it responds to changes in its environment.

During periods of hot weather, particularly when combined with strong sunlight, timber can expand and contract. Over time, repeated seasonal movement can contribute to changes in how a window fits and operates.

Older windows may be more susceptible because they can already have:

• Layers of old paint restricting movement
• Deteriorating or exposed timber
• Gaps around sashes and frames
• Worn cords, pulleys or other mechanisms
• Previous repairs that have deteriorated
• Timber movement or distortion
• Deteriorated putty or glazing
• Existing draughts or rattles

These issues can become more noticeable during a spell of hot weather.

Is your window becoming difficult to open?

One of the most obvious signs that your timber windows are struggling in warmer weather is a window that suddenly becomes difficult to open or close.

With traditional sash windows, layers of paint can compound the problem by restricting movement. Timber movement can then make an already tight-fitting sash even harder to operate.

This can be more than an inconvenience in summer. A properly functioning sash window can provide useful natural ventilation, allowing you to control airflow and help keep rooms comfortable without relying entirely on mechanical cooling.

If a sash has become stuck or painted shut, it doesn’t automatically mean the window needs replacing. Specialist renovation can release the sashes, address the underlying issues, service the pulley and weight mechanism and restore smooth operation.

Look out for these signs

A spell of hot weather can be a useful prompt to check the condition of your timber windows.

1. Windows are sticking

If a window that normally opens easily has become difficult to move, don’t force it. Excessive pressure can cause damage to the sash, cords or frame.

2. Cracked, flaking or blistering paint

Paint isn’t simply decorative. A properly maintained paint finish helps protect exposed timber from the elements.

Cracking or flaking can leave timber vulnerable to moisture penetration, which can eventually contribute to decay.

3. New gaps or rattling

Gaps around a sash can allow air, dust and noise into your home. With traditional sash windows, some clearance is necessary for the sashes to move, but over time these gaps can become larger or the sealing can deteriorate.

4. Soft or damaged timber

Pay particular attention to areas exposed to the weather, such as external sills and lower sections of frames. Soft timber can be an early indication of decay and should be investigated before the problem progresses.

5. Draughts

You might not notice draughts as much during summer, but if your windows are allowing noticeable air movement now, they are likely to be contributing to heat loss when temperatures fall again.

Don’t assume replacement is the answer

When homeowners notice problems with their windows, replacement can seem like the obvious solution.

However, old doesn’t necessarily mean beyond repair.

Well-made traditional timber windows can have considerable longevity, and in many cases the original components can be repaired, renewed or upgraded rather than removed altogether.

At Ventrolla, we assess the condition of the existing window before deciding what work is necessary. Depending on the property, this might range from relatively straightforward repairs through to a comprehensive renovation.

That could include:

• Repairing or replacing rotten timber
• Replacing sash cords
• Servicing pulleys
• Rebalancing sashes
• Releasing painted-shut windows
• Repairing or replacing sills
• Restoring glazing and putty
• Improving draught-proofing
• Upgrading glazing
• Repainting and finishing

Where timber is suitable for repair, our VR90 wood repair system can be used alongside traditional timber repairs to extend the life of existing windows.

Draught-proofing can make a big difference

One of the most effective ways to improve the performance of an existing timber sash window is to address draughts.

Ventrolla’s Perimeter Sealing System (VPSS) is designed to discreetly seal the gaps around existing sash windows while allowing them to continue operating smoothly.

The system uses low-friction weatherfin pile to create a seal around the moving parts of the window. This can help reduce draughts and rattles while improving comfort and reducing unwanted air movement.

Importantly, it doesn’t require changing the appearance of the window, making it particularly suitable where retaining the character of a period property is important.

What about glazing?

If your windows are in reasonable condition but you’re looking to improve thermal performance further, glazing can also form part of a renovation.

Depending on the property and the existing windows, options can include high-performance or slim double-glazed units, as well as discreet secondary glazing.

The right choice will depend on the individual window, the property’s character and any conservation or listed-building considerations.

In some cases, replacement double-glazed sashes can be introduced while retaining the existing box frame, providing an alternative to replacing the entire window.

Make future maintenance easier

Restoration isn’t just about solving today’s problems. It can also be an opportunity to make your windows easier to look after in the future.

Ventrolla’s Sash Removal System (SRS) can be discreetly incorporated into sash windows, allowing the upper and lower sashes to be removed more easily for cleaning, painting and maintenance.

This can reduce the disruption associated with future maintenance and, importantly, makes it easier to keep the timber and paintwork in good condition.

A little maintenance can go a long way

There are also simple things homeowners can do to help look after their timber windows during warmer weather.

Keep windows moving. If your windows are designed to open, use them regularly where possible. If a window suddenly sticks, avoid forcing it.

Check the paintwork. Look for cracking, peeling or areas where bare timber is exposed.

Keep sills and drainage paths clear. Dirt and debris can prevent water from draining away properly.

Check for early signs of rot. Pay particular attention to exposed external timber, especially sills and lower sections of frames.

Don’t ignore small problems. A sticking window or small area of damaged paint may seem insignificant, but addressing issues early can help prevent more extensive repairs later.

Every property needs a different solution

There is no single solution that is right for every timber window.

A Georgian sash in a listed townhouse will have different requirements from an Edwardian casement, and a window that’s suffering from paint build-up needs a different approach from one with significant timber decay.

That’s why at Ventrolla we restore first, rather than replace as a default.

Our heritage surveyors assess the condition of the windows and recommend the most appropriate approach – whether that’s targeted repair, full restoration, draught-proofing, glazing improvements or, where restoration genuinely isn’t viable, bespoke replacement.

The aim is simple: preserve what can be preserved, improve what can be improved, and only replace what genuinely needs replacing.

Worried about your timber windows?

If the recent heat has highlighted problems with your windows, now is a good time to have them assessed before those small issues become bigger ones.

Ventrolla offers a complimentary window consultation, giving you the opportunity to understand the condition of your windows and the options available,  without automatically committing to replacement.

Our specialists can advise whether your windows could benefit from repair and restoration, improved draught-proofing, glazing upgrades or replacement.