Conservatory roof - Glass or Poly ?

[Roly]

My conservatory roof is well past it's best and needs to be replaced, but I'm not sure which material is going to be the most suitable. The conservatory is a lean to, with a simple flat sloping roof about 4.5 metres by 2.5 metres. It faces due south, gets no shade whatsoever and can get extremely hot.

The glass supplier insists that thermal glass is without equal in reducing the heat transmission and offers a much better 'U' value.

The polycarbonate suppliers tell me that poly is more practical and that glass offers no practical advantage.

Obviously there's a significant extra cost to have glass instead of poly, so what would people suggest is the more appropriate solution ?

The conservatory is unheated, so thermal insulation isn't a major factor, it's heat build-up from sunlight that concerns me.

[Huge]

Until the first time it rains (or hails) on a poly roof. I said "UNTIL THE FIRST TIME IT RAINS..." You get the idea.

Glass is much heavier, though, so be sure the structure can support it.

Given the choice, I'd have glass.

[Tim Downie]

Ours has a poly roof and it gets way too hot! Also, it's about 10 years old and the material is becoming very brittle. It has quite a few holes in the outer ply. I wouldn't use it again.

Tim

[Roger Mills]

My 18-year-old conservatory has a triple-layer poly roof, with which I'm reasonably satisfied. It *does* get a bit too hot at times. We have reflective roof blinds which help a bit - but really need to be on the

*outside* to be really effective!

If I had to re-roof it, I think I would use poly again - but would give serious consideration to incorporating opening roof vents and/or roof-mounted extractor fans into the design - maybe using solar power to open the vents or drive the fans.

[Peter Lynch]

I'm also thinking about replacing my (poly) roof. One concern I have about using glass is the potential danger of it breaking. I'm led to believe that glass is a lot more brittle than a 2 (or 3) layer poly roof. I know first hand that things (icicles, footballs, bits off the main house roof) land on the conservatory roof. Some quite sharp and/or heavy.

Pete

[Huge]

My friends who have a entirely glass conservatory have wired glass in the roof and "fencing" along the eaves above it to stop things sliding off the roof onto the conservatory.

[Steve Firth]

Given the choice I had glass. One enormous benefit is that on a clear cold night you can turn out the lights and admire the stars from the comfort of a warm armchair.