Polycarbonate Roof Conservatory | Oak Conservatories

Polycarbonate Roof Conservatory

glass compared to a polycarbonate roof conservatory

Richmond Oak do not provide polycarbonate roof conservatory options, as we feel it our duty to promote the use of the most efficient glazing materials and to ensure they are ‘Fit for Purpose’. This includes keeping the sun’s heat out on hot days, keeping the heat in on cold days, reducing uv light penetration and glare, but also reducing the sound of rain hitting the roof, which can be quite deafening with polycarbonate (similar to the sound of driving along a motorway in the rain). During the 1990’s over 80% of conservatories were installed with Polycarbonate roofs, but now statistics show it is less than 30%. I’ll elaborate on this further down the page.

Our preferred glass roof option is SmartGlass® Ultra86, blue tint solar control glass which reduces glare, keeps out 86% of unwanted heat on hot days, 91% of ultra-violet light which causes damage to furnishings and which meets the most efficient insulation value of 1.0Kw/sq.m/hour. Which means it loses 1.0 kilowatts of heat per sq.m per hour (compared to 5.8 Kw/sq.m for single glazing. Please visit conservatory-glass-explained/ for more information. However, the following is factual information on polycarbonate.

Polycarbonate conservatory roofing material first became available during the middle of the 1980’s, at which time there was no such material as Solar Control Glass in the domestic market, which didn’t penetrate the market until around 2002. There was and still is, grey antisun which was quite oppresive or bronze anti-sun, which gave an orange glow in the room. Neither was terribly efficient. So when compared to normal clear glass, polycarbonate was at the time the most efficient solution.

Polycarbonate is available in a range of different thicknesses and finishes with better U-Values the thicker it becomes. 16mm polycarbonate is the lowest thickness with a U-Value of around 2.6. Depending upon specification, 25mm and 35mm polycarbonate typically have U-Values of around 1.6 and 1.5 respectively, provide a better insulation and are the standard polycarbonates in use today. However, the best is still 77% less efficient in keeping the heat in on a cold day. These thicker polycarbonates are claimed to provide slightly improved sound insulation than the thinner materials, but unless you enjoy the sound of heavy raindrops falling on your roof you should specify a good quality Solar Control glass, such as SmartGlass.

Polycarbonate conservatory roofing is available in a wide range of tints with different shade names applied by various manufacturers and suppliers. The tints will reduce glare and provide some shading. A polycarbonate roof conservatory is unlikely to be comfortably warm enough in the winter and in the summer the conservatory will become extremely hot. Polycarbonate is light and strong and is resistant to shattering. However, it is very rare for a tile to break a toughened glass roof and during the past 30+ years of installing conservatories I have only experienced 2 broken glass roof panes and neither broke through the inner pane. Whereas, during the 90’s I have had to change whole PVC roof panels dented by hailstones.

You should ask your designer or builder to show you samples so you can judge which will be the most suitable for your conservatory. But note that even the clearest polycarbonate will not be as transparent as glass and has the appearance of reeded glass. Certainly a clear polycarbonate might not be suitable for a south-facing conservatory in the summer months.

So why, 30 years later, do many companies still provide this inefficient material. There are two main reasons:

a) It’s easier to install… it’s much lighter in weight and can be cut to size on site, whereas toughened glass is much heavier and needs to be ordered to the correct size at least 7-10 days ahead of installation.

b) It’s cheaper! However, if it doesn’t do what you require it to do, then it is money misspent. A hand mower costs much less than a motor mower, but if you have a half an acre of lawn and a lot of spare time, it’s not fit for purpose.

I have a website www.conservatoryadvice.com for some 15 years and there’s rarely a week go by when I don’t get several calls asking if I can provide advice on replacing polycarbonate roofs with glass. This is not by any means as simple as it sounds and the existing conservatory roof and/or frame construction is often totally unsuitable to take the weight of the glass roof. Again, I recommend you visit conservatory-glass-explained/ for more information and why we do not provide polycarbonate roof conservatory options. The last time I used it was 1999.