Kent Building Plastics supply plastic or glass for roof glazing.

Many options exist for roof glazing and the material you choose will depend on the use of the space the roof area will cover.

If you are constructing a car port or simple canopy, there is no need for insulating glass or plastics. For such areas, corrugated pvc sheets may be all that is required or single glazed glass or plastic sheets that have a more traditional appearance may be used.

Where you have a room space to cover, the insulating requirements of the roof should be considered first. If the room is a porch and not part of a habitable space, again single glazing or thinner multiwall plastic sheets may be all that is required. But where you are constructing a room that will be part of a home and heating will be used, an energy efficient roof glazing is essential.

Multiwall Sheets are favoured over glass by some people for three main reasons:-

1. Glass is breakable and the thought of a breakable product over head is a worry.

2. Multiwall plastic sheets can insulate better than glass

3. Glass is more expensive and requires a stronger structure than multiwall plastic.

To answer point 1. above, Kent Building Plastics will only supply some types of glass for roofing applications.

For Single Glazed roof applications we supply Laminated Glass. This has a layer of plastic within the glass and this means that if the glass is broken it will not fall as the plastic will hold it together.

For double skin roof glazing, Kent Building Plastics will only supply Laminated glass as the inner skin with Toughened Glass for the outer skin. Toughened glass is stronger than standard glass or laminated glass but will shatter into small pieces if a breakage occurs. By using Laminated Glass as the inner layer, broken outer toughened glass will be retained by the Laminated glass and therefore the risk of glass falling on anyone in the room is reduced further.

Laminated and Toughened Glass units are expensive but Kent's consider the extra cost justifiable. Please remember when comparing our prices for glass roofs just how safe our specification is.

To answer point two above, it is true that plastics can insulate better than standard glass double glazing as shown on the table of comparative values. It is possible to upgrade double glazed units to give better ‘U’ values - details on request.

With regard to the cost of glass, there is a premium to pay but equally there are benefits. Glass transmits less noise - worth considering if you have a glazed roof within a living area as the sound of rain on multiwall polycarbonate sheets can be very intrusive. Also glass looks right on many roofs. The flatness and overall clarity that glass offers may be worth some extra cost to you.

* This U value is for standard double glazed units using 4mm Glass*. Glass U values can be improved by using thicker glass, creating a larger air gap between the glass sheets, by using thermally efficient glass such as 'Pilkington K' and/or by replacing the air in the unit with a gas.