Standard Clear Glass

 

Clear glass is used for most ordinary domestic windows where natural light and an unrestricted view are required.

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Within modern double glazing, clear glass may be combined with:

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• A low-emissivity coating

• Argon gas

• Warm-edge spacer bars

• Toughened safety glass

• Laminated security glass

• Acoustic glass

• Solar-control coatings

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Although the window may appear to contain two ordinary clear panes, the inner surfaces can include coatings that improve thermal performance without significantly changing the appearance.

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Double Glazed Glass Windows

 

A double glazed unit consists of two panes separated by a sealed cavity. The cavity is normally filled with dry air or an insulating gas such as argon.

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The glass specification can differ between the two panes. A unit might combine:

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• Clear outer glass with low-e inner glass

• Toughened glass on both sides

• Laminated outer glass with low-e inner glass

• Obscure glass with a clear internal pane

• Acoustic laminated glass with a different-thickness second pane

• Solar-control glass with energy-efficient glazing

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This allows one window to provide several benefits at the same time.

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When comparing quotations, ask the installer to describe the complete glass build-up rather than simply referring to standard double glazing.

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Frosted Glass

 

Frosted glass reduces visibility through a window while continuing to allow natural light into the room.

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It is commonly used for:

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• Bathrooms

• Toilets

• Entrance doors

• Side panels

• Utility rooms

• Windows facing neighbouring properties

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The frosted appearance can be created during manufacture or by applying specialist film to existing glass.

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Different products provide varying levels of privacy. Some soften outlines while others prevent most details from being seen through the pane.

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Window Frosting

 

Window frosting is often used as a retrofit solution where existing clear glass needs additional privacy.

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A frosted film can be applied to all or part of the pane. This may be useful where complete glass replacement is unnecessary or where privacy is only required at eye level.

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Possible designs include:

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• Fully frosted panes

• Frosted lower sections

• Clear borders

• Stripes or bands

• Decorative patterns

• House numbers or lettering

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Window film should be professionally applied where a neat, durable finish is required. The suitability of the existing glass should also be checked, particularly on large panes or sealed double glazed units.

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Satin Glass

 

Satin glass has a smooth, softly diffused appearance. It provides privacy without the strongly patterned surface associated with many traditional obscure glasses.

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It can work well in modern bathrooms, contemporary entrance doors and minimalist interiors.

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Compared with patterned glass, satin glazing usually creates a more even appearance across the pane. However, shadows and movement may still be visible when a person or light source is close to the glass.

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Samples should be viewed before ordering so you can judge the actual level of privacy.

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Obscure Glass

 

Obscure glass is manufactured with a textured or patterned surface that distorts the view through the pane.

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It is available in numerous designs and privacy levels, ranging from lightly textured glass to patterns that provide substantial visual screening.

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Popular locations include:

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• Bathrooms and shower rooms

• Front doors

• Side lights

• Staircase windows

• Ground-floor side windows

• Windows overlooking neighbouring homes

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Some patterns provide more privacy than others. The supplier should confirm the manufacturer’s privacy rating rather than assuming every obscure design offers the same level of screening.

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Pilkington Obscure Glass

 

The Pilkington obscure glass range includes several decorative patterns with different privacy levels.

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These products can be incorporated into double glazed units and may also be supplied as toughened safety glass where required.

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One of the benefits of using a recognised range is that homeowners can compare physical samples and select a pattern that suits both the property and the required privacy level.

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The orientation of the patterned surface should be confirmed before manufacture, as this can affect cleaning and appearance.

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Stippolyte Glass

 

Stippolyte glass is a well-known textured privacy glass with a fine, irregular pattern.

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It is widely used in bathrooms, toilets and entrance doors because it allows light to pass through while obscuring detailed views.

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Its appearance is more traditional than plain satin or frosted glass, making it suitable for many older homes as well as standard modern installations.

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Stippolyte glass may need to be toughened when used in a door, beside a door or in another critical safety location.

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Opaque and Milky Glass

 

The terms opaque glass and milky glass are often used to describe glazing that appears white or heavily diffused.

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Strictly speaking, fully opaque material would allow no view or light through it. Many products described as opaque are actually translucent: they block a clear view while still allowing some daylight to enter.

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Milky glass may be created using:

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• Laminated interlayers

• White films

• Printed or coated surfaces

• Specialist decorative glass

• Back-painted glass

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It is useful where a higher level of privacy is required, but the amount of light transmitted can vary substantially between products.

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Etched Glass

 

Etched glass has a decorative or frosted design created on the surface of the pane.

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Designs can include:

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• Borders

• Geometric patterns

• Traditional motifs

• House names or numbers

• Floral details

• Bespoke logos

• Period-style door patterns

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Etched glass can provide privacy while also becoming a decorative feature of an entrance door or window.

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True etched glass and applied decorative films can look similar from a distance, but they differ in cost, durability and manufacturing process.

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Toughened Glass

 

Toughened glass is heat-treated to make it stronger than ordinary annealed glass.

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If it breaks, it is designed to fragment into many relatively small pieces rather than forming large, sharp shards. It is therefore widely used as safety glazing.

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Typical locations include:

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• Glazed doors

• Windows close to doors

• Low-level windows

• French doors

• Sliding patio doors

• Bifold doors

• Large glazed panels

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Toughened glass is generally manufactured to its final dimensions before treatment. It cannot normally be cut or drilled after toughening.

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Although it is stronger against impact, once toughened glass breaks, the pane will usually collapse and leave the opening exposed.

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Laminated Glass

 

Laminated glass, sometimes called lam glass within the glazing trade, contains two or more sheets bonded around a transparent interlayer.

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When broken, the interlayer helps hold the glass fragments together. This means the damaged pane can remain in position rather than immediately falling away.

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Laminated glazing can provide:

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• Improved safety

• Greater resistance to penetration

• Better security after breakage

• Reduced outside noise

• Protection from ultraviolet light

• Additional protection in overhead glazing

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It is commonly used in accessible windows, glazed entrance doors, patio doors and locations where maintaining a barrier after impact is important.

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Toughened Laminated Glass

 

Toughened laminated glass combines toughened panes with a laminated interlayer.

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It can provide increased strength before impact while helping the broken glass remain together afterwards.

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This specialist glass may be used for:

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• Roof glazing

• Canopies

• Balustrades

• Structural glass

• Large glazed panels

• Walk-on glass

• High-level glazing

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The specification must be selected for the particular structural and safety requirement. It should not be chosen simply because it sounds stronger than standard laminated glass.

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Acoustic Glass

 

Acoustic glass is designed to reduce the transmission of outside noise.

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It commonly uses laminated glass with a specialist acoustic interlayer. The strongest results are normally achieved by combining panes of different thicknesses within a carefully designed double glazed unit.

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Acoustic glazing may be suitable for homes affected by:

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• Road traffic

• Aircraft

• Railways

• Schools

• Pubs and restaurants

• Commercial activity

• General street noise

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Glass alone does not determine the final result. Window seals, frame construction, trickle vents and installation quality can all affect sound reduction.

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Safety Glass or Security Glass?

 

Safety glass and security glass are not exactly the same.

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Safety glazing is intended mainly to reduce the risk of injury if someone falls against the pane or it breaks. Toughened and laminated glass can both satisfy safety requirements when correctly specified.

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Security glazing is designed to make entry through the pane more difficult. Laminated glass is often preferred because it remains held together after breaking.

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For accessible windows and doors, the installer may need to consider both requirements.

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Choosing Privacy Glass

 

When selecting privacy glazing, consider:

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• How much daylight is required

• Whether silhouettes are acceptable

• The distance between the glass and people inside

• Whether the window is lit at night

• The style of the property

• Cleaning requirements

• Safety-glazing requirements

• Whether the privacy level needs to cover the whole pane

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A glass that appears private during the day may reveal more when the room is illuminated at night. Physical samples provide a better guide than photographs alone.

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Combining Different Glass Types

 

A single double glazed unit can often combine several performance features.

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Examples include:

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• Toughened obscure glass for a bathroom

• Laminated low-e glass for an accessible window

• Acoustic laminated glass with thermal insulation

• Solar-control toughened glass for sliding doors

• Decorative glass within a secure entrance door

• Frosted safety glass beside a staircase

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The chosen frame must be able to support the thickness and weight of the final unit.

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Building Regulations and Safety Glazing

 

Safety glazing is required in certain critical locations, including low-level windows, glazed doors and glass positioned close to doors.

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Other requirements may apply to:

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• Roof glazing

• Balustrades

• Protection from falling

• Means of escape

• Thermal performance

• Ventilation

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The installer should identify these requirements before the glass is manufactured.

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Planning permission or listed building consent may also be needed where glazing changes affect a listed building, conservation area or other protected property.

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Find the Right Glass for Your Windows and Doors

 

The best glass specification will depend on whether your priority is privacy, safety, security, noise reduction, appearance or energy efficiency. In many cases, several different requirements can be combined within one double glazed unit.

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APN Double Glazing can connect homeowners with experienced local installers who can explain the available glass types and recommend a suitable specification for each window or door.

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Get in touch for expert advice and a free, no-obligation quote for replacement glass, windows and doors.