colorbond Vs polycarbonate pergola roofing

[ozzierog]

Hello all

We are about to have a pergola built. I have been trying to obtain information as to what roofing product will be the better way to go with regards to heat and light transference. Our builder is recommending a product called Solasafe HR1 polycarbonate by Ampelite but I am concerned about how much heat will be transferred as opposed to using colorbond? Or is it much of a muchness? If we do go colorbond, we would need some polycarbonate panels to allow light into a kitchen and double sliding doors of a rumpus room anyway.

Can anyone please shed any light on my dilemma (pardon the pun)? :)

[Barry_White]

Ozzierog

The transference of heat by any polycarbonate product is incredible and you would find in the summertime you would not be able to sit under it and in the winter sun it would still be very uncomfortable. If you do a search in the forums you will find a chart that I have posted about the the amount of heat radiated by the various types of polycarbonate and fibreglass translucent sheets.

The best Lysaght Colorbond sheet for heat is Flatdek.

[Bleedin Thumb]

Oz, There has been big advances in polycarbonate roofing in the last few years with dual layer construction and metallic heat reflecting polymers.

To choose the best product you have to know the Shading Co-efficient (SC) and the Light Transmission (LT) for the products.


I would look at Laserlite (Bayer) their XPT range have very good SC & LT ratings and good heat reflecting qualities.

There is also another imported product that has a 3 layer construction that is supposed to be very good (but expensive).

Speak to your local roofing supplier and get a brochure so you can compare the ratings. As Barry says a colorBond will always be cooler but if you need the light then its worth investigating the new polycarbonates.

[Ivan in Oz]

G'Day OzzieRog,
One problem I have seen, and had; is that some Birds start to
Remove the Stray Fibres as they get exposed after time;
in the Sunlight UV.

They do this to Roofing
and the Polycarbonate Electrical J-Boxes - This was in Gove NT.

I've seen Translucent roofing with NO Fibres,
perhaps this is what you refer to?????:?:?:?:doh:

[jags]

hi ivan

i would have to disagree with barry .

last year i got a large 30m2 dome patio installed out the back. i would never use colourbond for a patio roof as personally i think it looks cheap and tacky and it blocks out all the natural light ,which can be a big issue if your house is quite dark to begin with and the patio will be covering a door or window .

i went for a heat stop poly cab and the colour was called ice it is translusent but not transparent , and it is not hot to sit under in a 30 degree day . one issue i am worried about is that i have a tree that over hangs part of the patio so that some lefts fall on the patio roof and in the old days i remember poly cab getting stained by rotting leaves .

Also there is a new product that has two rows of trapped air cells in it that is supposed to be the best at letting the light through but not the heat .it looks great to but it is very expensive .

rob

one thing i did to improve the air flow was to have to have the patio higher than standard hieght .

[Barry_White]

hi ivan

i would have to disagree with barry .

last year i got a large 30m2 dome patio installed out the back. i would never use colourbond for a patio roof as personally i think it looks cheap and tacky and it blocks out all the natural light ,which can be a big issue if your house is quite dark to begin with and the patio will be covering a door or window .

i went for a heat stop poly cab and the colour was called ice it is translusent but not transparent , and it is not hot to sit under in a 30 degree day . one issue i am worried about is that i have a tree that over hangs part of the patio so that some lefts fall on the patio roof and in the old days i remember poly cab getting stained by rotting leaves .

Also there is a new product that has two rows of trapped air cells in it that is supposed to be the best at letting the light through but not the heat .it looks great to but it is very expensive .

rob

one thing i did to improve the air flow was to have to have the patio higher than standard hieght .

Well what would I know with over 30 years in the building trade 11 years with Lysaght selling both Colorbond, Translucent sheet and Polycarbonate, time with Spanline Home Improvements designing Glass Rooms, Screen Rooms and Patio Roofs helping customers removing polycarbonate roofs because it is too hot and replacing it with Colorbond.

As far as the Polycarbonate with two rows of trapped air cells it has been around for over 15 years and I can take you to a roof in a shopping arcade with it on the roof in Armidale NSW and you can't stay in there for any longer than about 10 minutes on a sunny day in the middle of winter dressed in winter clothes.

I have found over the years that people that have put polycarbonate up put up with it for quite a while rather than admit they made a mistake in using it.

Like you say it is a problem with leaves, dust and dirt settling on it and it eventually looks really crappy sitting underneath looking up and cursing the day you ever used it.

As far as light goes it is better to put in a couple of Solartubes and only Solartubes as they are the best allowing more light to come into the room.

You can now buy in Western Australia the best Patio Roof material available in Australia and that is Spanline products available here. http://www.spanline.com.au/asp/index.asp?pgid=10641&cid=5281&gid=1
They only thing with it it is expensive but the best is always the most expensive.

[David L]

Rather than Polycarbonate or Colorbond I would suggest an insulated roof on a patio if possible. No only do you have the advantage of being able to sit under it on a hot day, you don't get condensation under it possibly dripping off in winter.
I wish I had used it on my deck roof instead of Colorbond which gets uncomfortably hot. NO way I would use Polycarbonate for all the above reasons!

[Jacksin]

I agree with Barry.

People cover their entire pergolas with Laserlite etc only to find the heat becomes an issue especially if its a flat roof with no through air flow. I have seen steeper pitched polycarbonate covered roofs with ceiling fans installed to try and move the hot air. Someone mentioned Laserlite XPT, but from my experience sales staff at Stratco usually say its too dear and no one buys it.

I have done a few pergola re-roofs and used mostly colourbond (with off-white on the underside to give better light reflection) and the odd translucent opal Laserlite sheet over doors and windows.

[Barry_White]

Rather than Polycarbonate or Colorbond I would suggest an insulated roof on a patio if possible. No only do you have the advantage of being able to sit under it on a hot day, you don't get condensation under it possibly dripping off in winter.
I wish I had used it on my deck roof instead of Colorbond which gets uncomfortably hot. NO way I would use Polycarbonate for all the above reasons!

David

The insulated roofs are great the only thing you have to be careful about is some of the companies making have had problems of delaminating with the glue holding the foam to the roof material failing from the contraction and expansion with the heat and the cold.

[Ramps]

No way I'd be putting up a polycarb roof on a pergola in Adelaide :no:. I'd think that teh purpose would be to escape the heat from a poorly designed house in the middle of summer. With the number of close to 40 deg days that you've had recently I'd be thinking that you could throw out the webber with a hood like that. If it's light you need in the house adjacent to the pergola look at strip or two near the door

On say saying that I had a very comfortable one with the opal translucent PC in Bendigo but it was high and open on three sides (two being the longer sides) and designed to catch the southerly breezes.

good luck

[jags]

well barry sorry for having a opinion ,

But you with all your year of knowledge must agree that each product has it's pros and cons .And that the application to which each product is applied will depends on it's success .

hence the reason people ask for advice ..

i thought this forum was to help people that where asking the questions not to bag the people that are trying to help..

rob

[pharmaboy2]

Re polycarbonate roofs

The biggest disapointment for these are the clear ones -which were hugely popular about 10 yrs ago, and I have seen plenty of them ripped out since, but these days most of the polycarbonate I see is the ice or opal colour whcih transmits about 50% light, 50% heat. Now anybody expecting a product so well labelled with its heat reflectivity and expects something different deserves any disapointment..

However, when you compare it to colorbond, its about the same as any of the dark colours in colorbond, only 10 to 20% worse than shale grey, and a about a 30% gap to off white. Given most people will match to their existing roof, the question of whats better comes down to the indivdual situation, though clear should only be considered very carefully.

With correct selection, and due thought, either product is suitable, and both are unsuitable without thought and selection. I for one would spend 5 times as much time inside a house than under a verandah, so light levels inside are an enormously important consideration, and given I dont sit outside in the heat of the day, the lighting transmittance is more important than shade.

FWIW, I'm just about to install a 1.5m window eave with opal poly on top, with opal acrylic panel on the underside, which should give me about 25% light, and slightly better shading

[pawnhead]

i thought this forum was to help people that where asking the questions not to bag the people that are trying to help..I don't think that he's bagging anyone here, he's just offering his opinion which is very experienced and very valid.
However it is also a bit one-eyed (no offense Barry).

Here's a picture of the pergola that I installed about two years ago now:

http://i7.photobucket.com/albums/y266/holgerdanske/th_pergola1.jpg (http://i7.photobucket.com/albums/y266/holgerdanske/pergola1.jpg)

And here's a picture of the skylights that I installed in the adjoining family room:

http://i7.photobucket.com/albums/y266/holgerdanske/th_skylights.jpg (http://i7.photobucket.com/albums/y266/holgerdanske/skylights.jpg)

There's a huge deciduous liquid amber tree (over 15 metres I'd say) that constantly drops leaves and nuts on it. It's classed as a noxious weed so I don't need approval to remove it and I'm thinking of doing just that when I grow some bigger cajones.
On some summer days it gets very hot in the back room because of the skylights (which @ 1200 are over spanned for laserlite :p), but the deck doesn't get all that hot comparatively (That would have a lot to do with the shade that the tree provides mind you). If there's any breeze, then when I open the bifold doors completely, plus the windows and doors in the house then it provides pretty good ventilation. On the few very hot days of the year I'd stay in the lounge room where it's noticeably cooler having a high pitched roof over the ceiling.

Having said that, I'm not so sure that I want to get rid of the tree (even though it's playing havoc with my footings). It provides nice shade for the deck in summer, and it's nice to look at, especially through the roof and skylights at night when it's lit by a spotlight.
I know that the clear roofing will look rather tired before too long but I don't mind too much. It's not that much trouble to get up and sweep it off with my extension broom and a bucket of water.

I'm not about to 'admit that I've made a mistake' because I love the room and deck exactly the way it is. It's a lovely bright room that brings the outside in as much as possible, and it's a great warm, cosy, and bright place to sit on a sunny winters day when it's cold outside. :2tsup:

Horses for courses Bazza. Put up your steel shutters on your windows to keep your house extra cool in summer if you want, but if you want natural light in your house, then you have to trade it off with the heat that you're getting along with it. Unless of course you spend extra on double glazing, reflective films etc.

[Sturdee]

I have found over the years that people that have put polycarbonate up put up with it for quite a while rather than admit they made a mistake in using it.


I agree with you Bazza.

I roofed the BBQ area with polycarbonate and it let through way too much heat and light in the summer.

After a few years of putting up with it I covered the polycarbonate with heavy duty shade cloth and this has worked well together with 2 ceiling fans.

If I was to do it again I would use colour bond, insulate and line the ceiling.


Peter

[Barry_White]

Well come July next year all these arguments will be mute because all extensions have to meet BASIX and no way is a polycarbonate or translucent sheet going to meet the requirements without insulation under it.

Rob I was only stating my opinion it was you that said you disagreed with me and I am sorry if you took it personally and we can agree to disagree. Certainly as others have said the type of construction can have a bearing on the result.

The problem is when companies sell a product they only tell you the good things about their product. It is the unsuspecting that have to find out the faults with it after living with it. The problem is when they start to add reflective elements to the product it cuts down on the light transmission.

Like I said Solartubes are the best option for daylight in the daytime and at night you are going to have to turn on your low emission fluorescents anyway.

[Les Harris]

This is a timely discussion because today I got and accepted a quote for a wood framed pergola (about 6 m X 5 m). Our intended use is primarily in the seasons other than summer. Because neither of us can take much heat (I am 75 and have put up with excessive heat for a lot of my life) we will be inside with the airconditioner on during the worst of summer.

The polycarbonate sheet normally used by this builder is Ampelite Solarsafe and he gave us a chart of light and heat transmission numbers. Clear lets in 90% and 85% respectively whilst Dark Tint has 25% and 30% respectively, with a range in between The pergola will be fully open on the north side, partially open on the east and south sides, and against the house on the west, so the glasshouse effect will be considerably mitigated. The height of the roof has a bearing on this, of course, and this one will be about 2.3 under the barge.

A consideration for many will be how much light will be blocked by having solid roofing material over windows that normally admit light to the house. In our case a solid roof would excessively shadow the 2.6 M wide kitchen window.

It's horses for courses. The advantages and disadvantages of both solid and translucent roofing have to be weighed up and a decision made accordingly.

[jags]

No worries barry ...

It people like you and your wealth of knowledge that make this forum so great , and look what are disagreement has done for this thread ....:)

""The problem is when companies sell a product they only tell you the good things about their product. It is the unsuspecting that have to find out the faults with it after living with it. "

how right you are .....

saying that what is the colour life on colourbond as the darker colours seem to fade in direct sunlight after some time ,

Also what would you say is the major factor in the transferrance of heat . i think the only reason i find that i do not feel the heat under the patio is that the lowest piont is about 2.6m high and the patio is open on three sides so that the air flow is quite good ,and the fact that domes tend to have a lower pitch than gables may help ...? would there be any truth what so ever in that statement ?

rob

[Bleedin Thumb]

The problem is when they start to add reflective elements to the product it cuts down on the light transmission.




What is the problem? You don't want light transmission (LT) you go colorbond and have a low shading co-efficient (SC).

But sometimes people may want to have a some LT and can live with the subsequent medium to low SC. As has been said before the clear stuff deservedly had a bad rap but the new translucent shouldn't be written off.

I just specified it on a pergola (where the light was needed) only to have some old self opinionated builder talk my client out of it...no it wasn't Barry:D Maybe one of his old Lysart mates though:p' Just kidding Barry.

Here are some figure's for some of the XPT range

<table x:str="" style="border-collapse: collapse; 455pt;" border="0" cellpadding="0" cellspacing="0" width="606"><col style=" 23pt;" width="31"> <col style=" 56pt;" width="75"> <col style=" 19pt;" width="25"> <col style=" 59pt;" width="79"> <col style=" 19pt;" width="25"> <col style=" 50pt;" width="67"> <col style=" 23pt;" width="31"> <col style=" 56pt;" width="74"> <col style=" 23pt;" width="30"> <col style=" 54pt;" width="72"> <col style=" 18pt;" width="24"> <col style=" 55pt;" width="73"> <tbody><tr style=" 12.75pt;" height="17"> <td style=" 12.75pt; 23pt;" height="17" width="31">
</td> <td class="xl25" style=" 56pt;" width="75">Colours</td> <td class="xl25" style=" 19pt;" width="25">
</td> <td class="xl25" colspan="2" style=" 78pt;" width="104">Satin Cream</td> <td class="xl25" style=" 50pt;" width="67">Ivory</td> <td class="xl25" style=" 23pt;" width="31">
</td> <td class="xl25" colspan="2" style=" 79pt;" width="104">Satin Sage</td> <td class="xl25" colspan="2" style=" 72pt;" width="96">Eucalyptus</td> <td class="xl25" style=" 55pt;" width="73">Apple Blue</td> </tr> <tr style=" 12.75pt;" height="17"> <td style=" 12.75pt;" height="17">
</td> <td class="xl26">SC</td> <td class="xl24">
</td> <td class="xl27" x:num="">0.33</td> <td class="xl27">
</td> <td class="xl27" x:num="">0.35</td> <td class="xl27">
</td> <td class="xl27" x:num="">0.34</td> <td class="xl27">
</td> <td class="xl27" x:num="">0.34</td> <td class="xl27">
</td> <td class="xl27" x:num="">0.37</td> </tr> <tr style=" 12.75pt;" height="17"> <td style=" 12.75pt;" height="17">
</td> <td class="xl25">LT</td> <td>
</td> <td class="xl28" x:num="0.51">51%</td> <td class="xl28">
</td> <td class="xl28" x:num="0.35">35%</td> <td class="xl28">
</td> <td class="xl28" x:num="0.28">28%</td> <td class="xl28">
</td> <td class="xl28" x:num="0.19">19%</td> <td class="xl28">
</td> <td class="xl28" x:num="0.16">16%</td> </tr> </tbody></table>
So if you chose Satin Cream you would have about twice as much light as colorbond but you have only about 1 third of the heat transfer than if you were using clear polycarbonate (not really a fair comparison, I know)

Sorry I don't know what colorbond custom orb's SC rating is' and its probably irrelevantly. I would like to get radiant heat transfer data on both products to compare apples with apples...but that would be too easy.:((

[Barry_White]

No worries barry ...

It people like you and your wealth of knowledge that make this forum so great , and look what are disagreement has done for this thread ....:)

""The problem is when companies sell a product they only tell you the good things about their product. It is the unsuspecting that have to find out the faults with it after living with it. "

how right you are .....

saying that what is the colour life on colourbond as the darker colours seem to fade in direct sunlight after some time ,

Also what would you say is the major factor in the transferrance of heat . i think the only reason i find that i do not feel the heat under the patio is that the lowest piont is about 2.6m high and the patio is open on three sides so that the air flow is quite good ,and the fact that domes tend to have a lower pitch than gables may help ...? would there be any truth what so ever in that statement ?

rob

Rob

The interesting thing is that Bluescope does not warrant the Colorbond against fading although some colours are worse than others for fading. As you say the darker colours tend to fade more than the lighter ones although the lighter ones do fade. Even the gloss which is 25% gloss on Colorbond Surfmist which is the white colour fades too.
Here is a link to their warranty http://www.bluescopesteel.com.au/index.cfm?objectid=3476C572-0109-11D4-89EE00C04FCF6B8F

There are several factors that affect fading, the type or brand of paint, whether it has been wet whilst in storage in the pack, if it has been rolled using lubrication which some companies have done and sometimes the paint is just faulty. Usually the Colorbond paint will remain in good condition for at least 15 years.

Given that when any of these scenarios happen BlueScope should be contacted. Believe it or not their technical chemists can tell what has caused it and if the paint is faulty they will either replace it or repair it.

But if it is caused by some things they will reject the claim.

On one job that I inspected the paint was peeling after about eleven years and they accepted the claim and because it was a colour that had been discontinued they replaced the whole roof, all the flashings and cappings, the gutter and the downpipes and they paid for the removal and fixing of the whole lot no questions asked.

Certainly the type of structure can have a bearing on the amount of heat transfered and as Bleedin says and I can concede that some of the newer products can have better solar radiation figures.

[ozzierog]

Thank you everyone for all your feedback, and certainly an enlightening discussion!

Our structure will be 8.2 x 4.9m with a gable roof being 2.6m high at it's lowest point.
The east side (long) is enclosed, with north partially enclosed, and south up against the house, and just over half of the west side available to catch the southwesterly breezes. We are having a ceiling fan installed, but unfortunately do not have much (make that any) shading available in the summer.

The polycarbonate colour we're looking at is silver mist which has, to use Bleedin's terminology, a LT of 20% and SC of 22%. There is a 'twin wall' product available but it will add about another $4-5K. And yes, it would be good to get the radiant heat details of both ... Hmmm, it's looking like maybe a combination of colorbond with a few polycarbonate panels for light perhaps.

Didn't know about the colorbond fading though. This may be a stupid question, but just on the outside you mean?

Thanks again

Ozzierog

[ian]

Oz
Lysaght's used to make a version of Colourbond with aluminium foil stuck to the underside.
expensive, but it was brilliant at stopping heat transfer
when I worked in the bush, we build a 40 x 10 x 8m workshop in Tibboburra clad with the stuff.
The only ventilation was a series of vents along the ridge line.
It was cooler in the building than under a tree outside


ian

[icetea20007]

'Ozzi
And yes, it would be good to get the radiant heat details of both ... Hmmm, it's looking like maybe a combination of colorbond with a few polycarbonate panels for light perhaps.'

Hi All,
Just been reading on the post and finding heaps of helpful thoughts re what material to use for my up and coming DIY extension. Just wondering if Ozzi did go ahead with a mix of polycarb and colorbond in the end and how it turned out?
I have spoken with Stratco and they advised me that colourbond was the way to go as I am looking at putting in either of the above materials on an existing structure (5.3 X 2.5)in the back of the house which originally had shade cloths.
Could the Polycarb be rivitted to the colourbond or would there be a different installation requirements? :?

[Barry_White]

'Ozzi
And yes, it would be good to get the radiant heat details of both ... Hmmm, it's looking like maybe a combination of colorbond with a few polycarbonate panels for light perhaps.'

Hi All,
Just been reading on the post and finding heaps of helpful thoughts re what material to use for my up and coming DIY extension. Just wondering if Ozzi did go ahead with a mix of polycarb and colorbond in the end and how it turned out?
I have spoken with Stratco and they advised me that colourbond was the way to go as I am looking at putting in either of the above materials on an existing structure (5.3 X 2.5)in the back of the house which originally had shade cloths.
Could the Polycarb be rivitted to the colourbond or would there be a different installation requirements? :?

Icetea

When fixing Polycarbonate it should be overlapped each side onto the Colorbond but should be fixed with special screws with a very large plastic type washer because you have to drill a 10mm hole to allow for contraction and expansion otherwise the screw will tear the polycarbonate.

So you can't rivet the poly to the Colorbond.

Just remember Polycarbonate will transfer a fair amount of heat.

[ozzierog]

Hi IceTea

Would you believe we are having our pergola installed tomorrow! After much deliberation and conflicting advice, as our pergola runs north south, we have decided along the eastern side to install polycarbonate (in grey mist) to catch the morning sun, and colorbond along the western side for the afternoon sun. In winter, with the height of the pergola, the afternoon sun will becoming in under the pergola anyway. This way we're hoping to get the best of both worlds with heat reduction in summer and light in winter.

Even though our record heatwave has finished I'm sure there'll be more on the way before winter is upon us, so I'll be sure to keep you posted as to whether we're happy with the result or not!

Cheers

Ozzi :)

[icetea20007]

Hi ya fellas,
Thanks for the advise and yes, please keep me posted. I can't wait to see your end result with the pagola.

CHeers,
:U

[ingolby]

Hi Guys,

I've been trying to figure our what to roof the owner builder home I'm planning and was gravitating towards something I saw in "Natural Home Builder" magazine - flat panels which were referred to as 'refrigerator panels' which were colorbond on the outside then 100 mm of insulating foam sandwich (maybe polystyrene?), then colorbond again on the inside. One of the attractive features was an unsupported span of over 5000 mm.

Would this be the same stuff mentioned in Barry's post below?


David

The insulated roofs are great the only thing you have to be careful about is some of the companies making have had problems of delaminating with the glue holding the foam to the roof material failing from the contraction and expansion with the heat and the cold.


I'm also having no luck getting pricing out of Bluescope despite three online requests for a price guide.

I plan to harvest rainwater from this roof and wonder if anyone has suggestions regarding this.

Cheers

Ingolby

[Barry_White]

Hi Guys,

I've been trying to figure our what to roof the owner builder home I'm planning and was gravitating towards something I saw in "Natural Home Builder" magazine - flat panels which were referred to as 'refrigerator panels' which were colorbond on the outside then 100 mm of insulating foam sandwich (maybe polystyrene?), then colorbond again on the inside. One of the attractive features was an unsupported span of over 5000 mm.

Would this be the same stuff mentioned in Barry's post below?




I'm also having no luck getting pricing out of Bluescope despite three online requests for a price guide.

I plan to harvest rainwater from this roof and wonder if anyone has suggestions regarding this.

Cheers

Ingolby

Ingolby

Bluescope don't manufacture that type of roofing.

Here is what you want. http://www.paneltech.com.au/roofing.htm

[ingolby]

Ingolby

Bluescope don't manufacture that type of roofing.

Here is what you want. http://www.paneltech.com.au/roofing.htm

Cheers for the link Barry.

I think that must be the stuff.

I got confused by the use of the term colorbond which I understood to be a Bluescope proprietory product name.

I will look for their warranty regarding delamination.

Thanks again

Ingolby

[Big Shed]

Ingoldby, we used the sandwich cool room panels, 4" foam etc, as a roof on our houseboat. Great stuff, spanned the whole width, and best benefit of all, it mad ean excellent sunroof.

Only thing you have to watch out for is water leaking through the t&g joins between the sheets, but if done properly with stacks of Sikaflex then there is no problem. We didn't have any leaks over all the years we had the boat.

Had to go out and buy an air operated caulking gun, after 2 or 3 cartridges my hands were killing me!

[ingolby]

Thanks for that Big Shed,

I've just got a price on those panels

50mm..maximum ceiling span 3000..1200wide.$ 32.50/ sqm + GST
75mm..maximum ceiling span 4500..1200wide.$ 34.00 sqm + GST

Thats a shade over $ 200 bucks each for the larger panels which come in at 5.4 sqm.

Seems really cheap.. I could create a great kitchen / dining / living room flowing onto a covered deck with say 16 panels (8 on either side of the roof) for less than three and a half grand.

I guess they'd be best supported on a light steel frame or maybe with featured bush poles out at the deck end.

Thanks for your help guys.. really appreciate it!

[russall]

Excuse the hijacking...

I'm in debate on weather or not to use Poly or Colourbond...

I'm leaning towards the colourbond but am wondering how much heavier it is than poly? The reason I ask is I have run a beam over a 4m span which is boarderline as far as the span tables go. It would be fine if it was a continuous span, but this beam is a single span....

[Barry_White]

Excuse the hijacking...

I'm in debate on weather or not to use Poly or Colourbond...

I'm leaning towards the colourbond but am wondering how much heavier it is than poly? The reason I ask is I have run a beam over a 4m span which is boarderline as far as the span tables go. It would be fine if it was a continuous span, but this beam is a single span....

Russall

There wouldn't be a significant difference in the weight from Poly to Colorbond to make that big a difference on a dead load. The most important load is the live load which come from the uplift from the wind blowing across the roof surface. I think you would be quite safe with the Colorbond.

[autogenous]

http://www.eurocell.co.uk/conservatory.html

Australia can be a bit hot for polycarbonate in large enclosed areas depending where you live.