# Forum Home Renovation Roofing  roofing poly carbonate

## thirsty

Anyone using polycarbonate.
We're thinking of getting the AMPELITE silver mist. (the darkest one) 
I've heard bad things on here about the poly in general - too hot. But it has to be an improvement compared to sitting in the bare sun right? 
Anyone got feedback about poly carb roofing for a deck shelter?

----------


## DvdHntr

> Anyone using polycarbonate.
> We're thinking of getting the AMPELITE silver mist. (the darkest one) 
> I've heard bad things on here about the poly in general - too hot. But it has to be an improvement compared to sitting in the bare sun right? 
> Anyone got feedback about poly carb roofing for a deck shelter?

  I used it for a back pergola and it is hotter than roof sheeting but still gives more light and it is better than bare sun easily. I don't know the cost but you can use fabric shade material if you don't mind getting wet, much cooler and descent amount of light.

----------


## Colsy

I have been doing a fair bit of research on this issue and have decided to do a combo of steel sheeting and white polycarbonate.

----------


## nww1969

What brand are you looking at.
Someone on this forum mentioned to me when I asked about laserlite that
they have two kinds a standard and I think a laserlite 2000 which has a higher
sun rating and guaranteed for longer.

----------


## Bleedin Thumb

This type of roofing works thus... 
the more light that gets through (translucency?) ....the more radiant heat. 
If you want really cool and don't care much for light obviously you would use straight corro. 
If you want it slightly lighter but still cool go as Colsy says with a mixture say 1 poly to 2-3 corro etc. 
If light is a big factor and you want all poly you have to look at the graphs that the company supplies - you basically have to decide on light level  VS heat level, as there are many types of coatings and colours available. also lots of companies that produce it so its lots of homework.

----------


## Bedford

This is some Opal laserlite on a 38* day, it lets in plenty of light, but notice the shadow on the ground from what it has blocked out. It was actually pleasant under it. :Smilie:

----------


## SilentButDeadly

Used the Ampelite in the pearl colour on our 2.5m wide south facing verandah....we were worried about not enough light into kitchen window.  Needn't have worried.  When it dies I'll replace it with tin....it turns this verandah into a heat trap in our summers because it is only open at one end (unlike the one shown in the image in the previous post) so air circulation isn't great. 
There is a tinted, multiwalled product from Ampelite that will reject heat better than our stuff.....but it is both flat in profile and pfaffing expensive.

----------


## thirsty

I was going to buy the Ampelite "Silver Mist" which is abot 20% heat  20% light transfer. Its the stage 3 solasafe  -  the expensive one out of the solasafe range from ampelite. 
Wouldn't solid tin/corrugated roofing be hot too. 
I think the poly carb's thing is all about  "outdoor living, safe from the sun's UV rays" - so basically like having no roof  (therefore ....lot's of light) but no UV from the sun.  
I keep telling my self the darker you go in the poly carb range the more you move towards steel roofing. You're paying about $66 for a 3 metre sheet for this stage 3 sliver mist stuff. 
Ampelite(poly carb) stage 1 roofing 3m    about $40
Suntuff standard poly carb 3m  $35
steel corrugated from bunnings (zinc coating or something)  about $31 for 3 metres. 
So the standard poly carb is almost the same price as steel corrugated roofing at bunnings. And the steel stuff is not painted yet......more $.

----------


## SilentButDeadly

Most roofers I know reckon there's bugger all that splits the different types of poly carb sheeting except price and the gullibility of the punter... 
A steel roof will beat heat transmission since it reflects (depending on the colour) a significant chunk of the infra red and totally absorbs the rest.  What is re-radiated under the sheet is a a tiny percentage of that being applied - perhaps less than 5%. Whereas a poly carb sheet like the one you quoted is allowing 80% of total infra red to blast straight down onto you and your verandah....I know which one I'd prefer... 
A specialist roofing supplier is often cheaper than Bunnings......I know mine is.

----------


## murray44

> the more light that gets through (translucency?) ....the more radiant heat.

  I'm not sure that's right. That's what common sense suggests but when I did my research years ago I'm sure I found the white frosted colour let through almost the most light but was far from the hottest underneath.  
Shade sails aren't bad but I like the 'stay dry' option.......because it rains so much in Canberra...... :Rolleyes:

----------


## Bleedin Thumb

> I'm not sure that's right. That's what common sense suggests but when I did my research years ago I'm sure I found the white frosted colour let through almost the most light but was far from the hottest underneath.  
> Shade sails aren't bad but I like the 'stay dry' option.......because it rains so much in Canberra......

  
You may be right. I went through this exersize about a year and a half ago and I couldn't be bothered looking up my results.....I am fairly confident that it is a good generalisation though. 
What may vary is the new metalic coatings that some of them have. :Smilie:

----------


## thirsty

> Most roofers I know reckon there's bugger all that splits the different types of poly carb sheeting except price and the gullibility of the punter... 
> A steel roof will beat heat transmission since it reflects (depending on the colour) a significant chunk of the infra red and totally absorbs the rest. What is re-radiated under the sheet is a a tiny percentage of that being applied - perhaps less than 5%. Whereas a poly carb sheet like the one you quoted is *allowing 80% of total infra red* to blast straight down onto you and your verandah....I know which one I'd prefer... 
> A specialist roofing supplier is often cheaper than Bunnings......I know mine is.

  
The one I quoted is says it lets 20% heat through. Are you saying it will let 80% through? 
Hmmm do I want a sauna(steel roofing) or a greenhouse(poly)  :Eek:  
Our roof will be low on our deck but should be fairly open on 3 sides for air flow. Sydney is only hot for about 3-4 months of the year. hmmmmm :Confused:

----------


## China

just by experience and no maths, I installed lazerlite pearl over my spa walking from under this into an area covered in sand shade cloth, there is a big difference, the lazerlite cuts out moch more heat

----------


## cherub65

Design of the pergola is also a factor, try to incorporate a high pitch in the roof design as to let the heat escape, also can look better than flat roof lines

----------


## thirsty

i have a feeling that all the bad comments about polycarb roofing are coming from people who have sat under the clear stuff.
With the rolls royce dual-layer plastic roofing, the expensive stuff, the light heat ratios are worse than some of the poly carb corrugated ones.
Also the difference between the expensive twin wall poly and the normal corrugated poly is nothing.
eg
CARBOLITE (twinwall stuff) expensive 
clear    86% light     72% heat
bronze  42% light    45% heat
solar ice 20% light  25% heat 
Suntuff (corrugated stuff)
opal              45% light   46% heat
diffused grey  20% light   17% heat  
I don't like the colourbond corrugated steel roofing because it's only painted on the sun up side and it is grey metal underneath.
17% heat is not far off 0% heat transmission from corrugated. Wouldn't the steel roofing retain heat like a frying pan and transmitt something like 5% heat through the metal anyway? 
We already have some of the expensive twin wall type poly roofing on one section of the verandah which is only open on one side and it is not hot under there. You go under there to escape the sun.   It was there when we bought the house about 15 years ago so we don't know what shade, brand and hence heat and light properties it has but it looks like the clear type twinwall. 
We are caught between what colour of polycarb corrugated matches our deck and what it will actually be like to sit under....the latter is a lucky dip because there are no showrooms to go to look at this product on a built shelter.

----------

