Skip to main content

Tatraglass Heritage Mouth Blown cylinder is the only available replacement for historic Crown Glass.

The original glazing used in many historic properties was a glass called Crown Glass. This method was used for several centuries however has not been made for many years. The nearest equivalent Glass is our mouthblown cylinder class.

We can supply mouthblown glass with additional movement to mimic crown glass or we can select sheets with additional movement on request.

Our restoration glass is made by one of the oldest methods and comes in single sheets. This cylinder glass is unquestionably the finest in Europe for authentic sash window glass.

We supply for all sizes of project, from a single pane to a whole glasshouse in Quarry Bank Mill, and more (see some of the buildings with our glass installed below).

For the best thermal efficiency, we also pair our Heritage Mouth Blown cylinder glass with a modern glass sheet, to create Heritage ECO Laminated sheets or slimline Heritage Double Glazed units.

Our glazing is suitable for installing in stone mullion, steel and wooden window frames. We will advise you of the correct glazing choices for your project. We’re here to help you to get the correct glazing solution for your project, so please contact our expert team.

Read more

TATRAGLASS HERITAGE MOUTH BLOWN SINGLE SHEET – an authentic heritage glass

Until the 20th Century there were two methods of production for window glass. Cylinder Glass and Crown Glass. The latter ceased manufacture globally in the 1930s and is no longer available. Two factories in Europe still produce Cylinder Glass, ours is made in France, and we call it Heritage Mouth Blown in homage to how each piece is still made:

  • The glassmaker blows a bubble and draws it out to obtain a glass cylinder.
  • The cylinder is then heated and flattened before undergoing slow, controlled reheating to flatten the glass. This process is used to create our Heritage Mouth Blown glass.
  • This glass can be produced to more modern standards to improve thermal and acoustic capacity, resist Ultraviolet damage, and enhance security.

This fabulous glass shimmers and sparkles due to its uneven surface, with bubbles and inclusions catching and refracting natural light by day and artificial light by night.

Get in touch
Help Me Choose

Applications

Heritage Mouth Blown glass can be used with new and existing joinery work within traditional and historic pre-Victorian buildings, private houses, hotels and apartments.

Please speak to our team for advice on fixing methods, and use of the correct putty, which we can also supply.

  • Mouth blown

  • Pre-Victorian

  • 2mm (- 0.5/+1.5mm) thick

  • Ug = 5.6W/(m2.K) thermal rating

Pre-Victorian Restoration Glass

Combining our Heritage Mouth Blown glass and the benefits of modern glass, is classified as single glazing and has environmental benefits of lowering heat loss, because we pair the heritage glass to Low E glass, a hi-tech, high-thermal rated, with UV filtering to protect fabric and artefacts from harmful UV rays.

Applications

Heritage Mouth Blown Laminated glass can be used with new and existing joinery work within traditional and historic pre-Victorian buildings, private houses, hotels and apartments.

Fitting into the narrowest of window rebates, Heritage ECO Laminate is ideal for Georgian properties. Lightweight, allowing sash mechanisms to be retained, maintaining the authentic historic glass texture externally while reducing heat-loss, and cutting energy bills.

When using Laminated glass in sash window units, it is important to check the weights as they may need to be increased within the window frame to allow the window to work correctly.

Please speak to our team for advice on fixing methods, and use of the correct putty, which we can also supply.

Technical detail (click here)

Authentic heritage glass with added thermal and acoustic qualities.

The modern glass that we laminate the historic glass to has a special coating on it called Low E, which reflects heat back into the room and keeps harmful UV rays out while allowing heat from the sun into the room.

This unique system for replacing single glazing on pre-Victorian period properties is recommended by planning authorities in even the most sensitive conservation areas.

The laminated glass is made up of 2 sheets of glass laminated together to create a single, technically advanced sheet. The outer side is an authentic glass with the gentle waviness and imperfections expected, and the inside surface is the modern glass with it’s thermal benefits and the lamination process itself gives acoustic benefits.

Get in touch
  • Mouth blown

  • Pre-Victorian

  • 6.8mm thick

  • Ug = 3.6W/(m2.K) thermal rating

  • Mouth Blown glass laminated to Low E glass

Our Heritage Double Glazed range has the same benefits and characteristics of our ECO Laminate range, with the added benefit of even better protection against heat loss, which is achieved using gas fill to the unit. As a slimline conservation grade Double Glazed unit, units start from 10mm overall thickness and they are suitable for narrow rebate windows while retaining the external appearance of period glass.

Applications

Heritage Mouth Blown Double Glazed are only 10mm width and are suitable for installing in steel and wooden window frames. We will advise you of the correct glazing choices for your project. We’re here to help you to get the correct glazing solution for your project, so please contact our expert team.

When using Double-Glazed glass units, in sash window units, it is important to increase the weights within the window frame to allow the window to work correctly.

We will advise you of the correct putty to use and method of installation.

Please speak to our team for advice on fixing methods, and use of the correct putty, which we can also supply.

  • Mouth blown

  • Double Glazed 12mm Units

  • Pre-Victorian

  • 10mm thick

  • Ug = 1.5W/(m2.K) thermal rating

  • Mouth Blown glass with Low E glass

Get in touch

“Just confirming the safe arrival of my order of glass, that has just arrived, what beautiful pieces of windowpanes, they look amazing with the natural ripples but wonderfully smooth and clear to view through, wonderful craftsmanship, both myself and the decorator were very impressed.”

HERITAGE MOUTH BLOWN CUSTOMER

Technical specification

ProductDetailsSuitable for
Heritage Mouth Blown Sheet

Thickness: 2mm (- 0.5/+ 1.5 mm)
Thermal Rating: Ug = 5.6 W/(m².K)

Pre-Victorian
Heritage Mouth Blown ECO LAMINATED

Thickness: 6.8mm
Thermal Rating: Ug = 3.6 W/(m².K)

Pre-Victorian
Heritage Mouth Blown DOUBLE GLAZED

Thickness: 10mm
Thermal Rating: 1.5

Pre-Victorian

Heritage Mouth Blown was previously known as French C2.

CASE STUDIES:

Tatraglass Heritage Mouth Blown Glass has been used in countless restoration projects throughout the UK. Here is a glimpse of just some of the buildings which have used Tatraglass for their authentic restoration glass. 

  • Buxton University Building (formerly known as Devonshire Royal Hospital)

  • A Grade II listed former stable block with what was the world’s largest unsupported dome (44.2m)

  • Refurbished and reopened in 2003

  • Restored with Tatraglass Heritage Mouth Blown glass throughout

  • Shuttleworth’s Swiss Garden’s Grade II* listed Grotto & Fernery

  • an integral part of the Swiss Garden’s original Regency design

  • Just over 4,280 panes of Tatraglass Heritage Mouth Blown glass were used

  • in the re-glazing of the wings and dome of this beautiful structure.

Please note. All of our restoration glass types are manufactured using the traditional methods. It is intended for these products to be used for restoration, where modern float glass would give an inappropriate appearance. We cannot guarantee against small marks, seeds (bubbles), small surface scratches and surface distortion in this glass, which are not faults but characteristics of the product, which is designed to blend in with old or original period glass.

This type of glass cannot be compared to float glass, which is mass produced using modern manufacturing processes, and is virtually perfect in its appearance.