Polycarbonate Vs Glass

[matroska]

Hi Guys,

So First of all non-automotive question (hence appearing in the lounge).

Need a transparent roof for a part of the house. The two options are

1) Tempered/Toughened Glass

2) Polycarbonate.

Glass would cost about 70K more than poly-carbonate (for the entire section, and would further require an additional sticker to reduce the intensity of the sun light)

I've googled this but I want to know first hand experience from people who have this in their houses in Sri Lanka.(not some greenhouse guy from the UK) in terms of maintenance etc.

Your opinions and comments are highly appreciated.

Cheers.

[iRage]

My parents have a section that is covered. Used to have the poly stuff but after a few years it got a dull haze that couldnt be cleaned. Not sure if thst is the norm or if it was a problem with the specific brand they bought. Now they have glass and looks much nicer and easy to clean.

[iRage]

Ohhh...and they had to put a stronger frame as the glass solution was heavier.

[matroska]

Thanks Irage. Well I've just heard from another person that the poly carbonate does tend to get a bit dirty with time so it's not brand specific i guess.

[Sampath Gunasekera]

  On 4/28/2016 at 8:59 AM, iRage said:

My parents have a section that is covered. Used to have the poly stuff but after a few years it got a dull haze that couldnt be cleaned. Not sure if thst is the norm or if it was a problem with the specific brand they bought. Now they have glass and looks much nicer and easy to clean.

Polycarbonate is a kind of plastic (PC is a thermoplastic polymer) and it is the same plastic type use for making CDs/DVDs..

Loss of transparency is very common when expose to UV radiations for a longer period (@ Outdoor applications).

At the production of polycarbonate sheets , UV stabilizers are added.

But time being UV stabilizers on the product react with UV rays and get finish & reach to end of their life time and then haze appearance comes. This is very common.

Not only polycabonate , other plastics like ABS (Acrylonitrile butadiene styrene) use for car dashboard trims also contains UV stabilizers. Time being UV stabilizer shelf life gets over and plastic surface starts to decay by making cracks. We generally say plastics don't decay easily, but there is a big role behind adding UV stabilizers. For plastic water tanks made by LLDPE (Linear Low Density Polyethylene) need required amount of UV stabilizers for at least 10 years, which protect the item at least 10 years until manufacturer's warranty period expires.

Edited April 28, 2016 by Sampath Gunasekera

[iRage]

Damn..that was intense...thanks Sampath...

Yes..I've always known that plastic rots....have plenty of stuff just disintegrate

[PreseaLover]

And also, the glass is more clearer than the polycarbonate so you can easily see the stars in the sky in the night or the birds that fly in the afternoon, if you are an observer of nature and all that shiz, specially when having a drink its a lovely sight to watch... so polycarbonate doesnt give that clear picture...

[The Stig]

To add to what Sampath said there are two qualities of polycarbonate sheets in the market, the lower grade one will generate a yellow hue due to uv light sooner.

[Rumesh88]

@matroska - I went through the same dilemma sometime back when my house was under construction. The final decision was to use bottle green glass for the skylight of 8'X10' in size. The pros of using poly-carbonate sheets are light weight, marginally lower cost (at prices that time), and less heat absorption and radiation. If you are using glass ensure some ventilation at the roof level(easily said than done) and/or use heat reflecting stickers (this may jack up the cost substantially).

[Sampath Gunasekera]

Additionally to glass panels & PC, I have seen some glass roofing tiles (size and shape exactly same with normal clay tile/"rata ulu") on old buildings.

My grand parents residence also had same and was much nicer. Light intensity also reduced due to curving stricture. But may be expensive and not suit for matroska's requirement.

Edited April 29, 2016 by Sampath Gunasekera

[zeem35]

Polycarbonate will become opaque and fragile after 4-5 years for the high intense heat and sun light!

It started disintegrating over the years

We had to replace it so double cost!

I heard recently there is a polycarbonate sheet with 10 years gurantee but then again after 10 years??

Pros:

Cheaper

Lighter

Diffuses light

Cons:

Lifetime

Edited April 29, 2016 by zeem35

[matroska]

Thanks for sharing your ideas guys and Sampath for that really informative post: glass looks like the way to go.

  On 4/29/2016 at 4:01 AM, Rumesh88 said:

@matroska - I went through the same dilemma sometime back when my house was under construction. The final decision was to use bottle green glass for the skylight of 8'X10' in size. The pros of using poly-carbonate sheets are light weight, marginally lower cost (at prices that time), and less heat absorption and radiation. If you are using glass ensure some ventilation at the roof level(easily said than done) and/or use heat reflecting stickers (this may jack up the cost substantially).

Heat resistant sticker costs about 2000 per 4' X 1' piece as per the quotation.

[Crosswind]

What you really need to do is a cost-benefit analysis. If glass was 70k more than the polycarboate (you haven't mentioned the cost of it), if replacing polycarbonate sheets every 5 years or so may sound like an easier option on the pocket (cost is spread out over time), I suggest going for it... it all boils down to a simple cost benefit calculation

[matroska]

Got an actual quotation for the Sky light I'm just putting it here to get an idea about the whole costs

Total Surface area : (11*11.5 = 126.5 SQFT)

Glass with Heat Reflecting sticker : Rs 275,000/-

Glass without Sticker : Rs 210,000/-

Poly Carbonate without any stickers : Rs.173,700/-

[iRage]

Not much wiggle room in there between the two products (price wise). How are you mounting it ? What would be the price difference be in the ancilliary stuff like frame, etc...that would be needed ? In my parent's case the frame they had for the poly sheet was too weak to support the glass and needed re-enforcement. They decided to ditch the whole thing and get a new one done up which could also be slid open/close

At the end of the day...the poly sheet looked rather cheap after sometime...the glass one had a bit of..uhh..."refinement" in it....

[matroska]

  On 5/2/2016 at 9:39 AM, iRage said:

Not much wiggle room in there between the two products (price wise). How are you mounting it ? What would be the price difference be in the ancilliary stuff like frame, etc...that would be needed ? In my parent's case the frame they had for the poly sheet was too weak to support the glass and needed re-enforcement. They decided to ditch the whole thing and get a new one done up which could also be slid open/close

At the end of the day...the poly sheet looked rather cheap after sometime...the glass one had a bit of..uhh..."refinement" in it....

It's something like this (but a lot smaller)

The price includes the frame which consists of Rectangular Aluminum tubing (3"X1") .I got the quote for the entire thing .

[krajeevan]

  On 4/28/2016 at 8:59 AM, iRage said:

My parents have a section that is covered. Used to have the poly stuff but after a few years it got a dull haze that couldnt be cleaned. Not sure if thst is the norm or if it was a problem with the specific brand they bought. Now they have glass and looks much nicer and easy to clean.

Expand  

Do you have any idea where they bought the tiles. Been looking for glass tiles for some times. Thanks

[matroska]

  On 2/5/2019 at 8:55 AM, krajeevan said:

Do you have any idea where they bought the tiles. Been looking for glass tiles for some times. Thanks

Expand  

I think It's actually @Sampath Gunasekera s grandparents house had glass tiles. I think mascons have a clear roofing  tile but it's not glass I think -probably PVC .

 

[matroska]

  On 5/2/2016 at 6:19 AM, matroska said:

Got an actual quotation for the Sky light I'm just putting it here to get an idea about the whole costs

Total Surface area : (11*11.5 = 126.5 SQFT)

Glass with Heat Reflecting sticker : Rs 275,000/-

Glass without Sticker : Rs 210,000/-

Poly Carbonate without any stickers : Rs.173,700/-

Expand  

UPDATE:

Since this thread got bumped up thought of writing the final outcome - so that someone may find it useful down the line. 

I eventually settled for Glass mounted on a frame made of rectangular aluminum tubing. The cost (excluding the sticker) was a bit less than 250,000. initially I did not go for the sticker - and the view was fantastic specially on full moon nights. However I opted for a sticker within a few weeks of settling down at the house since the intensity of the sun was just too much. Ended up going for a reflective sticker that provided a bit of shade cost me 50,000 for 120+ square feet.(May 2017 - might be different now)  The light intensity is a bit less  and the view isn't too badly affected. It's been over 2 years since the initial installation and  over 1 1/2 years since the sticker and so far there are no complains at all. On the other hand i have used polycarbonate canopies and those have already started looking crappy.  

I'd say for such an application glass is clearly the best option.