PVC Window laminated glass query.

Westford

I'm at the stage where I'm about to order windows. For a stack of reasons, I've opted for PVC windows. The frames are chosen, but I have an option on the glass. As it stands the windows would be double glazed, argon filled, with low-E glass.... (hard-coat low-E coating on the outer most surface of the internal glass). The overall glass sandwich is 28mm (20mm cavity) wide.
I have the option to change the glass, such that the outer glass is changed to a laminated one.... 3mm glass, sheet of poly(something), and another 3mm of glass.
I'm curious to know what would be the advantage of going this route. It would add about 16% to the cost. A quick google points to improvements in strenght, safety, and sound insulation (and some mention of UV filtering)..... But are there any significant improvements in thermal insulation.
Also, is there any downsides to this glass?
Any feedback appreciated......

Slig

most significant difference is strenght, laminated glass is what is used in car windscreens, the sheet of plastic in the middle holds the glass together if it shatters

RKQ

Strength is the only advantage.
Of course if it breaks it won't shatter and cut you as badly!

Are any window cills below 850mm high?
If so it could be a reference to the Building Regulation requirements.

Could be worth while in glazed or patio doors etc.

Westford

There are some windows below 800mm. But my understanding was that toughened glass would be sufficient in these windows. (Of course laminated would improve safety).
Good point on the patio doors!

RKQ

Its a matter of taste and budget then!

I assume the cill height started the discussion on toughten and laminated glass.

Is toughten much cheaper?

Its your choice.:)

sydthebeat

where kids are a factor i would always, always, always go for laminated glazing both on internal and external panes.

re toughened vrs laminated i was under the impression that toughened was significantly dearer than laminated because of the special heat treatment.

http://www.windowstoday.co.uk/glass_safe.htm

theres good info above.

Supertech

Good point on the patio doors!

Are these not fitted with safety glass as standard by most manufacturers ? Cost of same should be included in original price.

blackiebest

Toughened glass should not be used for windows. The reason it is is money, it is cheaper. It will scatch if you look at it and is a burgulars dream! OP pay the 16% and have a good glass package. Toughened glass is suitable for ballustrade/guard rail etc but crap for windows, Dont use it!