Polycarbonate roofing

[Stumps]

Putting in a what we thought would be simple, flat roof pergola (5degree pitch) out the back (south facing) roughly 6m widthx 4m length x 2.8m high in area with timber posts/beams. We were originally looking to have a polycarbonate sheet roof becuase our back room is a sunroom and would like natural light to come through . We Have had two people come to quote so far.....

one bloke was happy with our thoughts and said the more expensive polycarbonate roofing types are very good at reflecting the sun and it wouldnt get too hot underneath

The other bloke said, it would be ridiculously hot using polycarb and we should use an insulated roof system which doesnt let any light thru but provides full shade

Im very confused and starting to think about abandoning the polycarb idea due to it being too bloody hot in summer.

Any experiences, tips etc would be appreciated,
Cheers
Stumps

[smac]

There are two tricks, from my experience.

Firstly, use the newer type of polycarb that actually does reflect the heat away (the older stuff is basically waterproof shadecloth). Secondly, and this can be done afterwards when you determine if it really is necessary, put a whirly or other kind of outlet for the hot air in the roof somewhere. This will allow any trapped hot air to escape.

Having open ends also helps, fully enclosed can become a little bit like an oven.

I certainly wouldn't add the expense of an insulated roof based on the 'too hot' advice of an installer. Speak to everyone you know that has a pergola about what material they used as well.

[heater31]

What smac said.

here is the stuff you need from Burnside plastics http://www.burnsideplastics.com.au/html/suntuf.html even has some technical details at the bottom to help

[Stumps]

Thanks for your advice

[Iron Fist]

go just colourbond sheets and then allow for 2 sheets to be the poly carbonate so natural light can still get through but also keep it cool!