Sash Window Draught Proofing

If you own a period home it’s wise to protect any unique or original features that add value and charm to your property. This is particularly important when dealing with sash windows, which are prone to gradual decay and can serve as a major source of heat loss.

Fortis & Hooke DS Perimeter Draught Sealing System

At Fortis & Hooke not only do we recognise this problem, but we have also developed an innovative DS Perimeter Draught Sealing System to negate the issue. The Fortis system is widely accepted as the most comprehensively tested, detailed and effective system of its type in the market, and it can be used to completely seal any sash window.

Why Are Sash Windows Prone to Draughts?

You may be surprised to learn that sash window draught problems are largely caused by their inherent design because they require a 3mm air gap around each sash to allow for smooth and seamless opening.

This small gap is responsible for causing several issues with sash windows, particularly draughts, rattles, reduced energy efficiency and dust and water ingress.

Our system addresses these challenges, delivering a secure, functional, and cost-effective solution.

Why Is Our Draught Sealing System Superior?

The Fortis & Hooke ethos has been built on a desire to restore rather than replace sash windows; we constantly strive to develop new techniques that enable us to maintain functionality and retain aesthetic appeal. Fully-sealed and restored windows could add significant value to your home and you will also be restoring a piece of treasured British architectural heritage.

Our Fortis DS Perimeter Draught Sealing System was pioneered to help us to realise our ethos whilst it has also been developed to provide a stylish and high-performance solution that guarantees longevity.

sash window draught proofing image of operative inserting a nail    sash window draught proofing    


Benefits of the Fortis DS Perimeter Draught Sealing System

  • Customised Solution for Period Properties: Our system has been developed to address common period property window issues so we are ideally-placed to offer a customised solution for period home owners. Our expert team boast extensive knowledge of sash windows in period architecture, and we have applied our skills and experience to ensure that our draught sealing system is perfectly tailored to produce optimal results in any given situation.


  • Restores Sash Window Functionality: Whilst other companies may be preoccupied with restoring the core aesthetics of your sash windows, this could all be in vein if they don’t fundamentally function right. As part of our superior draught-proofing service, we ensure that your windows are completely sealed, re-weighted, re-corded and renovated; we want to make sure you are delighted with the end result.


  • Viable Alternative to Sash Window Replacement: When some sash window owners experience issues with their windows they may initially think that full replacement is the best option. In most instances, this isn’t the case and it’s important to keep in mind the value that fully-restored original features can add  to your home. Our sealing system will help your windows withstand the test of time, eliminating the need for a potentially costly replacement.

Sash Window Draught-Proofing FAQs

Don’t double glazed units provide a more effective solution?

We have already touched on how the 3mm gap around each sash can cause significant draughts around your windows, but double glazing would not necessarily provide a direct solution for this issue. Instead, our draught-proofing system can effectively stop the excess air movement around the box and each sash, resolving the problem whilst also increasing heat retention.

Is sash window draught-proofing more energy efficient than double glazing?

We have already confirmed that draught-proofing provides a more effective and tailored solution for damaged sash windows, but it also compares well with double glazed units when it comes to efficiency. In short, draught-proofing can achieve up to 80% of the energy performance of a double-glazed unit, which is impressive when you also consider the age and additional benefits attached to original sash windows.

Can damaged or rotten sash windows be Draught-proofed?

If your sash windows are suffering from rot or other damage our team will need to carry out all repairs first to ensure everything is structurally sound. From there your newly-repaired windows will can be sealed.

How long does it take to Draught-proof a Sash Window?

This can depend on the extent and the scope of the job in question but in our experience it usually takes just days to expertly seal sash windows. If individual components are damaged or rotten then the process may take longer but our team will work quickly, diligently, and effectively to complete all work in a time-effective manner.