Glass

SIZE LIMITS

MAX SIZE for 4mm GLASS

If glass exceeds 1300mm in both directions or one side exceeds 3000mm or the area is greater than 2.5m² then 6mm glass must be used.

MAX SIZE for 6mm GLASS

6mm glass can generally be used upto 4m sq or upto 120kg but this would need to be checked by the glass supplier.

MAX SIZE for PATTERNED GLASS

Max size for patterned glass is:-

1320mm wide x 2140mm high

SATIN glass is the only exception. This is limited by the same maximum sizes for 4mm glass.

TOUGHENED GLASS

WHERE TO USE TOUGHENED GLASS

In doors where it's within 1500mm of the floor level.
Next to doors where it's within 300mm of the edge of a door and within 1500mm of the floor level.
Glazing which is within 800mm of the floor level.
It's also recommended if it's within 800mm of a fixed structure that is above floor level (e.g. Window seat or bath)

Below is a visual guide to the areas requiring toughened.

(Laminate glass can also be used instead of toughened)

OTHER TOUGHENED REQUIREMENTS

Shaped units and units with holes (e.g. for extractor fans and cat flaps) should also be toughened.

This is not regulatory but a requirement by many sealed unit manufacturers to prevent the unit from breaking.

PATTERNED GLASS

Pilkington Obscure Glass Brochure

ARCTIC

GLASS WEIGHTS

SINGLE GLAZING

4mm Glass - 10 kg/m²

6mm Glass - 15 kg/m²

6.8mm Glass - 16 kg/m²

DOUBLE GLAZING

4mm + 4mm Unit - 20 kg/m²

4mm + 6mm Unit - 25 kg/m²

4mm + 6.8mm Unit - 26 kg/m²

6mm + 6mm Unit - 30 kg/m²

6mm + 6.8mm Unit - 31 kg/m²

TRIPLE GLAZING

4mm + 4mm + 4mm Unit - 30 kg/m²

4mm + 4mm + 6mm Unit - 35 kg/m²

6mm + 6mm + 6mm Unit - 45 kg/m²

THE MAXIMUM UNIT WEIGHT A 2 MAN TEAM CAN SAFELY HANDLE IS 75 kg

SOLAR CONTROL

Solar Control Glass for Windows

Solar Control glass used in conservatory roofs in not suitable for use in windows and doors because the Easy Clean coating on the external surface can get damaged when cleaning the glass.

Solar Control glass without the Easy Clean must be used for windows and doors.

COOL-LITE 176 is a suitable solar control glass.

ACOUSTIC GLASS

The acoustic rating of glass is determined by its ability to reduce sound, measured in decibels (dB). A higher decibel value signifies greater noise reduction. For example, glazing with an acoustic rating of 35 dB will reduce incoming external noise by 35 decibels, meaning a 38 dB rating would provide even better sound insulation.

While triple glazed offers good thermal properties, it may not deliver the sound reduction you might expect.

Here's why...

Dissimilar Glass Thicknesses:

The most effective sound-reducing glazing units (whether double or triple) use panes of different thicknesses. This is because each thickness of glass has a different critical frequency (where it vibrates most easily and transmits sound). By using different thicknesses, you spread out these critical frequencies. If a triple glazed unit uses three identical 4mm panes, it's more likely to suffer from resonance issues than a double glazed unit with, say, one 4mm and one 6mm pane.

For comparison, here are some typical acoustic ratings.