Polycarbonate roofing - advice sought

I’d like some opinions on the multi-layer polycarbonate roofing sheet.

I've built conservatories for folks before using 25mm panels of this but I've never had one of my own to use all year around. Now that I'm thinking of adding one to our gable end, I'm wondering how they fare. I'm proposing to use the 32mm translucent (opal)1.25 x 4mtr panels and I hear that the "U" values are very good for them in the Winter whilst not being too hot in the Summer. Some say that the rain can be loud on them but, as they have 10 layers, it's probably not too bad within the interior.

What I like about the panels is that they're very quick and easy to put up, don't need a massive supporting structure and, currently, these are available locally at about 115€ each. Cheap, cheap, cheep, pretty Polly, aawk !!

The missus is talking "Proper roof" but, by my estimation, that will be at least 6 times dearer.

So, if you've got a conservatory/outbuilding that is roofed with these panels, I would be grateful to hear what you think.

Cheers m'dears.

Yes indeed, Daniel, that helps. Do you think that the Phil Collins effect is largely due to the thin outer skin or the resonance of the material? I mean, why aren't roof slates or glass as noisy?

Anyway, if you have any more info or links that you think might help but shouldn't go on an open forum, do please PM me.

Cheers !

Hello, I can give you our imput as fenestration trade suppliers ( I wont mention our business as its not proper..)

Polycarbonate as mentioned does have a tendency to sound like Phil collins is on his drum set when raining,,

long and short is if your on a budget then polycarb is the solution,, and most of my clients on past history will put up with the noise,,

the times have changed on polycarb, many years ago it was very thin and rubbish and the sun bleached it yellow within a short duration, nowadays you get a thicker mcultiwall and have a lot more options on size and finish,

If however your pockets are a little deeper then go for active blue glazed units,,

Clear polycarb that we sell has a 1.25 u value for 32mm thick or a U value of 2 for 35mm thick

both are "multiwall" and of course available in clear, opal, bronze and also a solaguard variant for heat retention.

as to the weather anything over 25mm thick would be ok with the french hailstorms etc,,

and yes dead easy to fit and compared to glass units (24mm thick in roofs generally) they like you said don't need nowhere as much in way of a support frame..

hope that helps..


Just looked at the devis and it says roof in "thermoclear 32 mm". I know it was UV treated and that they offered an option which was white on the inside surface which would have been cooler. But we wanted to get as much light as possible. It's made to be used in winter with well-insulted aluminium frame, good double glazing etc.

This is what it looks like (I hope this works!)

Thanks for the info, Terry. How thick is the roof of your conservatory? I've just come across a 55mm version but it's more than twice the price of the same area of the cheapo BricoDepot 32mm panels. Even so, it may be worth the extra loot for the extra insulation and soundproofing.

I like the stuff and it would make the job so much easier. I will, however, have to convince the missus. I can erect the poly sheets myself - done a few - but, if it comes down to building a 'proper' roof, I'm going to get a roofer in. I'm getting too old for that malarkey.

Cheers !

Thanks for the info, Becky. A lot of the early poly roofs were only 16mm and, if it's in clear as against opal, it will transmit some heat. Some of the up-to-date ones have special heat-reflecting coatings, I believe - although I don't suppose the 'BricoDepot' stuff has that. Do you know how long they've had their roof and what thickness it is?

Your French neighbours are wrong about it breaking; it's seriously tough. When I was at Dartington College, one of my students wouldn't believe my 'unbreakable' claim, so I gave him a 6mm thick off-cut and a hammer and let him beat 7 bells out of it on an anvil. It distorted but it did not break; he was very impressed. As long as it is properly supported, as Terry says, it will not break.

Don't listen to the doom merchants, Becky. We've had more than 50 cm of snow on our conservatory rook and regularly have 20 cm and no sign it was even bending, let alone breaking. It has also resisted fierce hailstorms with no damage. After all, it's the same stuff as car headlights are made of these days. We thought of a glass roof but the price was prohibitive, particularly as the roof isn't just rectangular and everything had to be cut precisely to size and shape. It's been there for eight years so far and no sign of deterioration. The heat problem is eased by venetian blinds at the windows and, as I said earlier, an awning, either internal or external.

My parents had a polycarbonate roof put on their conservatory in France too.

When it rains, you can't really sit out there the noise is so loud. In the summer, its too hot in the day, in winter its too cold. You can only really use the room mornings and evenings in summer or all day early autumn / late spring.

Also, the French people come in and start making noises, saying they can break if there is snow / will only last x years etc. If you can afford to go with a better roof I think it would be worth it in the long run.

I have had a polycarbonate roof for some years, Kent, on an aluminium framework put up by professionals. The walls and windows of the conservatory are all glass "anti-effraction" which reassures the insurance company and complies with French law to prevent kids running into them and going straight through. But the roof is polycarbonate. Yes, when it rains you know about it. Loud enough to drown the sound from the TV if we leave the door open but absolutely fine once the door is shut. It does get very hot in the summer which is why we installed a motorised awning above it. However, I don't know if what was used on our roof is the same as what you're planning to buy which may be better at reflecting the heat.