FAQ

Frequently Asked Questions

1. Do I really need safety glass for the doors in my house ?

With current Regulations glass in any part of a door less than 1500mm high and in windows less than 300mm from a door need to be safety glass i.e. toughened or laminated. Although, with small panes of glass less than 250mm in width (as long as the total area is less than 0.5 m2) 6mm standard glass can be used.

If you are considering buying a door (or window) with small panes, 6mm standard glass can be considerably cheaper in small panes than toughened glass, but if you require double glazed units, remember 6mm units are a minimum 18mm thick and toughened units are a minimum 14mm thick.

see safety regulations

2. Will the windows in my house need safety glass or not ?

Any windows 300mm or less from a door as described above need to be, but also any glass in windows that are 800mm or less from floor level (inside or out) need to be too.

see safety regulations

also see safety glass types

3. What is the difference between 'K' glass and 'Low-E' glass ?

To put it simple, 'K' glass is a type of 'Low-E' glass.
'K' glass is basically a Low Emissivity Glass, or Low-E glass. The name 'K' glass is the trademark name that Pilkington Glass has called this type of Low-E glass.
High profile marketing and distribution over the years has led the 'K' name to be more widely associated with this product to date.
Different types of Low-E glass have different U value properties.

4. So what is 'Low-E' glass and what does it do ?

When using a 'Low-E' unit a lot of the heat that you lose through the glass is reflected back into the room due to a very thin film on the glass which is on the inside surface of the sealed unit. The unit has a faint tint compared to ordinary units.

RedKite are using 'Guardian Low-E 1.4D' which has very high thermal insulation, high enough to keep U values down to Building Regulation Standards even with a 12mm air space.*

* See our Low-E performance figures.

5. Do I have to use 'Low-E' glass ?

With the introduction of new Building Regulations Part L in April 2002, all new windows and doors (doors with 50% glass or more) in houses and attached conservatories (or detached heated conservatories), need to comply with these regulations and also incorporate 'Low-E' glass units.
At the moment, replacement units do not need to comply to these regulations, although if you replace the entire window, both window and glass will need to comply.

For more questions and answers on these building regulations click here

This is just a guideline. For more information visit the web site www.safety.dtlr.gov.uk/bregs/brad12.htm

6. How can I tell if I have 'Low-E' glass ?

When your 'Low-E' unit is first fitted it will normally have a sticker on it which tells the installer which side of the unit should face inwards.

The 'Low-E' unit also has a faint tint compared to ordinary units.

There are small devices you can buy to test for 'Low-E' units by pressing them to the glass. If you are unsure this is probably the best way to detect a 'Low-E' unit.

7. Are sealed units guaranteed ?

Yes, but glazing of the sealed units have to strictly comply to the Glazing Rules and Regulations for timber frames, using glazing blocks and the correct silicone.

In PVCu frames the glazing system is different: the units need to be placed onto suitable packers (all blocks and packers are available free of charge with your sealed units from RedKite) and 'dry glazed', making sure all the drainage holes are visible and clear from blockage. Also no edge seal must be visible and in contact with direct sunlight.

A sealed unit glazed any other way may considerably shorten it's life span and will invalidate the guarantee.

The company's invoice acts as the guarantee from the date issued, and only when paid for in full.

8. How do I know if I am using the right silicone to glaze sealed units into timber frames ?

Silicone has to be 'Low Modulus, Neutral Cure' and of high quality.
We have known from past experience that certain makes of such silicones can still affect the seal of a unit, if you are in doubt the staff at RedKite will test your silicone free of charge for compatibility. Glazing silicone sold at RedKite is 100% compatible.

9. What is the thickness of a double glazed sealed unit ?

Using 4mm glass, as follows:
14mm (4-6-4)
16mm (4-8-4)
18mm (4-10-4)
20mm (4-12-4)
22mm (4-14-4)
24mm (4-16-4)
28mm (4-20-4)

The 28mm unit is the standard unit used by RedKite in PVCu frames, usually thinner units are more common in timber frames.
Most of the older timber frames tend to accommadate 14mm or 16mm units, with the newer timber frames (complying with the building regulations part L) typically being between 20mm - 24mm.