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Sash windows double-glazing

Everything you need to know about our double-glazed sash windows

Exterior photograph of a period red brick facade home with white sash window, period front door, granite steps and window sills.

Common problems with sash window glazing

Most if not all double glazed sashes suffer from some or all of the following problems:

  • Glazing bars are made much too wide in order to hide the double glazed unit edge seals
  • Glazing bars do not have the correct moulding detail
  • Glazing bars are stuck on to the glass
  • Meeting rail splay or rebate is pinned on
  • External glazing bones are stuck on to the glass
  • Glazing beads used instead of putty
  • Mock external putty line stuck on to glass

The above design details result in a poorly made and visually unacceptable sash window.

The difference with Bolger Sash Windows

Bolger Sash Windows double glazed sash windows are very different:

  • Glazing bars are exact match of original bars
  • Sashes are correctly made – glazing bars are not stuck on
  • External glazing bones are not stuck on. They are housed into the sash in a lattice frame
  • Sashes are putty glazed on the outside

The result is that Bolger Sash Windows double-glazed sashes are by far the best-made, which makes them the most authentic, glazed sashes available.

We offer a wide range of glazing options including Pilkington Optitherm double-glazing which will reduce the heat loss through the glass by approximately 65% when compared with single glazing.

And if you choose BENGglas vacuum glass, your windows will outperform triple-glazed windows in terms of energy efficiency, comfort and soundproofing.

Stages of a typical sash window restoration project​

After your initial enquiry with our office, we will follow up with a detailed inspection of your windows together with a written report and estimate. This service is free of charge in residential circumstances. Ordinarily, with commercial projects, there is a report fee which is waved upon the awarding of the project. 

Work to your windows will be carried out by a team of experienced carpenters on-site and will include:

  • Fitting a draught-proofing system
  • Replacing sash cords
  • Rebalancing weights
  • Replacing staff beads & parting beads
  • Repairing or replacing frames and sashes
  • Ensuring easy sliding action


Exterior photograph of a period red brick facade home with white sash window, period front door, granite steps and window sills.

Sash windows

Front of the newly restored Dun Laoghaire Baths on a sunny day. A one-story period building painted white. Two sets of two sash windows on either side and a period Georgian door in the centre with a fan light above it. All made by Bolger Sash Windows. Two low granite steps from the footpath up to the door. Low granite wall with white railings on either side of the steps that have a granite pillar at the end of both.
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New Sash Windows

Photograph of the restaurant in Fern House Avoca Handweavers featuring beautiful bespoke timber panelled sash windows.
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Sash Window Restoration

Exterior photograph of a period red brick facade home with white bay sash window, blue period front door, granite steps and window sills.
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