Draught-proofing Sash Windows

Draughty windows aren’t uncommon. Over time, windows of all different materials begin to wear — opening the door to uncomfortable and costly draughts and leaks. So, it’s important to tackle these issues as soon as they arise.

That’s why Core Sash Windows have put together this guide that answers everything you need to know about diagnosing and fixing draughts.

Signs you have a draught in your sash window

A draught may not be obvious or glaringly apparent depending on the severity of the draught.

Some critical signs and symptoms of a draught include:

  • Feeling a chilly breeze — even in if the heating is on.
  • Whistling, wheezing or rattling sounds coming from your sash windows.
  • The glass fogs up or excessive quantities of condensation buildup on the windowpanes.
  • A noticeable spike in energy bills.
  • Damage around the seals or signs of dry-rotting on the timber.


Causes of draughts in sash windows

Draughts coming from your sash windows can be caused by a variety of different reasons — almost all of them are to do with aging, damage or improper maintenance. If you’re noticing your sash windows are looking a little worse for wear, maybe it’s time to consider upgrading them.

Although a draught may not seem like big problem, it can become a costly issue – increasing your bills and effecting the sale of your home because of damaged, non-compliant windows.

Some of the causes of Draughts include:

Rotting or weathered timberTimber that’s been exposed to the elements for years without proper treatment can begin to rot and crack, making it more porous and allowing outside air into the home — even when the windows are locked shut.

Damaged putty The glazing putty that’s used to secure a window inside the timber frame can also begin to crack and break off over time — letting air in through the tiny gaps between the windowpane and the frame fitting.

Structural damage Hard impacts or particularly harsh weather can damage your sash windows and cause anything from hairline cracks to severe structural damage that will let in a draught should they worsen or be left alone.

Unbalanced weights Balancing weights — designed to keep the windows counterweighted to secure correctly — can be improperly fitted, damaged or not the correct weight, causing an imbalance. This imbalance means that the top sash isn’t being secured to the top of the frame on lifting, letting in a draught.

Ways to draught-proof sash windows

If you’re unfortunate to experience draughty windows, it’s important not to worry as it can be fixed. There’s plenty of things you can do yourself or have handled professionally that can fix the problem. 

The best ways to draught-proof your sash windows are:

Installing draught excluders

It’s no secret that older timber used on traditional singly-glazed, Victorian sash windows can begin to let in a draught as the material weakens over time. So, an effective method of draught-proofing your windows is installing a draught excluder.

These are strips covered in bristles that help block air from coming into the house and can be used to line the weak points of a window — like joints, the perimeter of windowpanes or staffing beads.

The staffing beads can be removed from an existing window and new ones can be fitted with a discrete PVC plastic carrier that holds the draught excluder in place. These can be slid in and out of the carrier at any time.

Apply window sealer 

Because windows are slotted into a frame, there are always hairline the gaps between the glass and the timber – and these gaps can welcome unwanted draughts over time. An effective sealer — like silicone sealant or a variety of adhesive weather strips — can be used to stop air seeping through the gaps.

This is a cost-effective solution that not only looks discrete when applied, but can be done yourself quickly and easily. 

Considering secondary glazing

If your windows are older, single-glazed windows — and you don’t necessarily have the time or budget to fit an entirely new sash box and frame — adding secondary glazing can help protect against draughts caused by aging or damage.

A second layer of glass and frame is simply inserted behind the existing frame and sealed off. This doubles the amount of insulation offered by the existing one and seals off any draughts without burdening homeowners with the cost of an entirely new installation.

Upgrading your curtains

As temporary as it may seem, a pair of thick curtains can help alleviate many of the symptoms of a draught, while also helping to lock heat inside your home.

Consider a refurbishment

If the damage is extensive, or these solutions don’t fully fix an ongoing draught, it may be time to consider a refurbishment or a new sash window installation.

Benefits of draught proofing sash windows

Handling a draughty sash window is an unwanted headache for all homeowners and tenants. However, fixing the problems as soon as possible means homeowners can reap the rewards of a high-quality refurbished window and avoid costly repairs.

Some of the benefits of draught-proofing your windows include:

  • Preventing uncomfortable cold Draughts — especially in the cold seasons.
  • Reducing the amount of noise caused by air flow into the home
  • Improved functionality of the windows
  • Substantial savings on heating bills


Signs your sash windows need replacing

Sometimes, no amount of repairs and refurb solutions can save a window and stop it from causing a draught — it needs to be replaced. 

If your windows are suffering from a draught, look withered and tired and suffering from dry-rot and structural damage, it’s time to call a professional.

Core Sash Windows offer an extensive selection of sash windows, casements and doors tailored to your exact specification. Our team of FENSA-accredited fitters will ensure you have the highest quality installations possible.

So, if you’re in need of windows, enquire now and book your free, no-obligation measuring and quote today.


How do I temporarily draught-proof my sash windows?

For those looking for a more a quick fix to their draught problems, there are temporary solutions homeowners can explore without ripping out the entire unit and starting again.

Some of the most used temporary draught-proofing solutions include:

  • Silicone sealant 
  • Self-adhesive weatherstrips
  • Window film
  • Metal weatherstrips
  • Temporary window sealer

Can you seal sash windows?

If your draught is coming from a window that’s typically not used for anything other than natural light, then sealing it up completely is a viable option. 

Despite not being able to open that window, it will eliminate draughts from that particular window — saving money on bills and stopping cold, uncomfortable draughts getting in.

Are timber sash windows draughty?

No, timber windows aren’t any draughtier than UPVC or aluminium windows. 

A well-made timber sash window that’s been properly fitted, treated and sealed can and does stop draughts and resists the elements as well as alternative materials.

What should I do if my sash windows are draughty?

If your windows are draughty — and any attempts to fix the problem at home haven’t worked — it’s best to call a professional.

Luckily, Core Sash Windows are able to diagnose your problems and help refurbish your current windows or build and install bespoke ones to suit your needs. Get an instant quote now or book in a free, no-obligation measuring and see how we can help you today.

Enjoy being warm and comfortable!

call us: 020 3302 2060 or email: [email protected]

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