Window Glazing

Ironmongery for Sash Windows, Casement Windows and Doors
before and after
Before and After: A townhouse refurbishment in Kildare

Window Glazing

window glazing

Your window glazing will depend on a number of factors from personal choice to building regulations and thermal requirements.

Timeless Sash Windows are a timber joinery company and supply and fit complete window and door units. The glass is manufactured to order for each project and fitted to the sashes by our specialist glazing team.

I had a chat with them this week to discover the important details regarding glass choices for you.

You can choose from traditional single glazing, hand blown old glass, double glazing with argon gas, slim double glazing with krypton glass (from the street this looks like single glazing) or triple glazing. Within these choices there are also further options such as acoustic and thermal performance.

Click here to watch our video on window glazing.

Double Glazing and Slim Glazing

The double glazed units can be filled with Argon gas, Krypton gas or Xenon gas. These are sealed with a warm edge Swiss V spacer bar which is an insulating plastic composite material that acts as a barrier against heat loss and keeps the edge of the sealed unit warm which reduces the risk of condensation on the window. This plastic composite also keeps the panes of glass apart at exactly the specified distance which can be 4mm/6mm/8mm/12mm and is the barrier against the loss of the insulating gas. For example, in a Slim Glaze unit, this gap will be 4mm and each pane of glass itself will be 4mm resulting in a 4 / 4 / 4 specification.

The gas efficiently insulates against cold, thus reducing the U-value of the glass. When compared to a traditional single glazed window, the Slim Glazing system results in a 77% reduction in heat lost through the glass.

The glazed units all come with a 5 year warranty. The Timeless Slim Glazing System protects the edge of the double glazed units to ensure that no water damages the seals. We use specialist acrylic putty that is specifically compatible with these units to achieve maximum life expectancy and efficiency of the windows.

The spacer bar is available in black or white depending on the aesthetics of the home and paint colour choices for the windows.


double glazing

Pilkington K Glass

This is a low E – glass that is designed and produced by Pilkington in the UK. It  forms the inside pane of the double glazed unit and is a low emissivity coated thermal glass that reflects heat back into the room whilst also allowing solar gain.

Pilkington Spacia Glass

Pilkingotn Spacia glass is a great solution for old windows where a narrow section is only possible. It is an insulating glass unit that is made up of a low E outer glass and an inner pane of clear float glass with a vacuum of just 0.2mm in between. The vacuum produces excellent thermal efficiency and requires much less space between the panes when compared to a gas fill. Hence, in old windows particularly, where the original frames only allow for a narrow section, you can still achieve modern standards of insulation. The overall thickness of a Pilkington Spacia glass unit is only 6.5mm.

Acoustic Glass

In some properties, noise reduction is a priority. In these situations we can use high quality acoustic laminated glass such as Pilkington Optiphon. This can result in a reduction of noise levels up to 50 decibels.

Safety Glass in Windows and Doors

In addition to double glazing, there are building regualtions that stipulate the use of safety glass in windows up to 800mm from the floor level.

Toughened glass has been specially heat treated to make it much stronger than ordinary glass. Also when it breaks it will shatter into small granular pieces that are not sharp, thus reducing injury.

There is also laminate glass which has a plastic material in between the two layers of ordinary glazing. When this breaks the shards of glass will remain stuck to the plastic layer and will cause less damage.

Fire Safety Glass

Some windows require specialist fire safety glass. This has been laminated during production and offers various degrees of fire resistance from 30 – 60  minutes. It also remains clear during a fire which makes it easier to evacuate a building. In addition is does not radiate heat. Despite these enormous safety advantages, this glass does not compromise on aesthetics during normal use.

When we are fitting fire safety glass we bed it into the frame using a heavier fire retardant tape also.

fire retardant window tape

Historic Glass

Where possible during window conservation we keep the original glass. Our glass supplier can also produce double glazed units with crown glass as the outside pane of glass. This is a top of the line product.

Double glazed cylinder glass

Stained Glass / Leaded Glass

Stained glass is beautiful and very popular in fanlights and sidelights as well as in historic windows. We work closely with a stained glass specialist company on these projects and the results are very impressive.

Stained glass window panels

Protective Films for windows

In addition to the glazing choices, there are also a range of protective films that can be applied at an extra cost for specific purposes such as protecting against fading of the interior elements such as upholstery and art work by the application of a UV film. We use a specialist company who are experts in the application of such films and will guarantee their integrity.

UV protective film for windows

Electric Glass

For serious wow factor, rooms that need privacy can be fitted with electric glass. This glass will go from clear to opaque at the flick of a switch. It is ideal in bathrooms and is more hygienic than curtains or blinds. Once fitted, an electrician is required to wire up the glass to operate correctly.

Duplex Glazing Unit 

In order to achieve a Victorian, Georgian or Edwardian look without multiple panes, we have the option of duplex units (also known as astragal bars, back to back bars or bond on bars). These can be manufactured to any arrangement including curved Gothic style windows.

Bond on Bars

Your Choices

Our survey expert will guide you through the choices available to you at the point of sales. For further personalised advice, comment below or call us on 046-9023323.

Published on 21st February 2019

Jennie Ritchie, Timeless Sash Windows


Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.

We are using cookies on our website

Please confirm, if you accept our tracking cookies. You can also decline the tracking, so you can continue to visit our website without any data sent to third party services.