It ’ s been more than 15 years since Pilkington Activ™ became the first commercially available self-cleaning glass . Since then , over a million square metres of the product have been sold for a wide range of applications , from conservatory roofs to commercial facades . Despite this , it is still a new product to some in the industry and some are unsure of the best ways to install it .

Here are some pointers to bear in mind .

1 . Be aware of lead .

Lead carbonate can leach from flashings in rainwater and be deposited as a white stain onto glass . This effect can occur on any glass , not just self-cleaning glass , but is one of the things it can ’ t remove by itself .

Inorganic contamination is not broken down by the self-cleaning coating and can be difficult to remove . It is recommended that lead used where there is a risk of rainwater run-off onto the glass be treated with patination oil ( or similar ) to reduce the risk of leaching .

It ’ s worth noting that when selfcleaning glass has been stored in a warehouse for a long period prior to installation , it may take up to seven days to become fully activated

Lead flashings should be treated on both sides , particularly if they lap directly onto the glass .

2 . Dual action .

Not all self-cleaning glass is the same . Pilkington Activ™ is referred to as dual action , as there are two stages involved .

Stage one utilises a ‘ dirt eating ’ photocatalytic reaction to break down organic deposits such as mud , while stage two is based on the ‘ water loving ’ hydrophilic coating , which spreads water evenly over the surface of glass to form a thin film instead of forming into droplets .

This helps to wash dirt away , preventing the formation of drying spots and streaks . Make sure the self-cleaning glass you install is dual action .

3 . Pick your angle .

The minimum recommended angle for a roof containing self-cleaning glass is 10 degrees from horizontal . Any less and the rainwater may not run off and wash dirt away effectively .

4 . Silicone-free .

Sealants and gaskets that are lubricated with silicone oils can ’ t be used with Pilkington Activ™ as they can mask the hydrophilic and photoactive actions of the coating , the technologies that make the glass self-cleaning .

If silicone is used and left on the glass , the silicone contamination causes water beads to appear on the surface when it is raining or wet .

Several alternative sealants , gaskets and cleaning agents can be used that are compatible with self-cleaning glass .

Installers can go above and beyond by following this checklist , and their customers can save time , energy and money in the long term by choosing selfcleaning glass

5 . By the sea .

Wind-blown spray in coastal areas can cause salt crystals to adhere to the surface . As salt is an inorganic contaminant , it can ’ t be broken down by the photocatalytic action of Pilkington Activ™ .

While this is worth considering , the technology will make the glass cleaner than ordinary glass after a light hosing or rainfall .

6 . Tried and tested .

It is important to install self-cleaning glass that has been tested to the necessary standards .

A new European Standard , EN 1096-5 , has been introduced that evaluates the self-cleaning performance of coated glass . This standard allows specifiers to differentiate between glass with a classified self-cleaning performance and without .

7 . High and dry .

The amount of cleaning needed depends on how dirty the glass is and the amount of rain it is exposed to . During long , dry spells or if the windows are particularly dirty , some manual cleaning

might be required , either by gentle hosing to replicate rainfall or by using a soft cloth and warm soapy water .

8 . Activate .

The activation of the glass occurs via a chemical reaction between UV rays from natural daylight , oxygen and the coating . It ’ s worth noting that when self-cleaning glass has been stored in a warehouse for a long period prior to installation , it may take up to seven days to become fully activated . After then , it will continue to work as long as it ’ s exposed to daylight , even in dull winter weather .

9 . Hard water .

It ’ s rare that self-cleaning glass needs to be rinsed , but if the water is very hard , then it should be softened with a domestic softener or through adding a couple of drops of detergent .

10 . Job done .

After self-cleaning glass has been installed in a building , care must be taken during any further construction work to avoid staining or damaging to the coating .

Lead carbonate can leach from flashings in rainwater and be deposited as a white stain onto glass . This effect can occur on any glass , not just selfcleaning glass

Rusty deposits , plaster products or adhesives can affect the coating . So , after building work is completed , the glass should be cleaned as soon as possible by rinsing with water to remove all traces of dust and abrasives which may have accumulated during construction .

Installers can go above and beyond by following this checklist , and their customers can save time , energy and money in the long term by choosing self-cleaning glass .

For more advice on self-cleaning glass , visit : www . pilkington . co . uk / activ