Clear 35mm polycarbonate roofing sheets - anyway to stop the garage heating up so much?

[Daniel B]

Afternoon all,

11 years ago I replaced the horrendous and leaky concrete/asbestos sheets on my garage with lovely new 6m long polycarbonate ones.

They are great, watertight (Had to change the seals once) but if it is sunny it can get up to 45c in there, even today it's already up to 24c.

Aside from buying replacement sheets (Which I am reluctant to do as they should have a good 10 years left in them) in an opal or some kind of solid colour finish, is there anything I could paint onto the top of them to help make it a more bearable climate in there on a sunny day?

I have seen (But forget the name) there are some reflective strips you can poke and push into give you a reflective surface, but I have 5 sheets, each of 6m in length, so I think when I looked last it would have cost a packet, and also taken a very long time to achieve fitment.

IIRC it was in the region of hundreds of pounds, and a new set of roofing sheets would likely be around £1000.

Thanks

Dan

 

[Tigercubrider]

I have a conservatory with triple wall plastic roof.

Originally it had twin wall, I fitted solar powered roof fans. You cut a circular hole, it fits either side of the plastic and pops open/closed with a quarter turn. The vent was a mushroom head fan. didn't leak but not a massive difference.

I changed the roof over tie and fitted a man sized pop up vent that would do nothing for security but this helps with temperature build up.
I also ran thin steel wire in parallel lines following the line of the roof. and cut bamboo blinds (you could use canvas) to width. added rings that clip to the wires and they act as shades. They seem to make the most difference.

You could try a simple white sheet held off the top of the roof? stopping the heat gain is easier than removing heat.
My neighbour used to paint his green house with a whitewash type stuff every Summer

 

[Daniel B]

Thanks TC, the issue with fitting something on the inside, is that I have a lot of items stored up there in the roof space, plus a currently immobile car taking up half the garage, so it would be quite an undertaking to get into a position where I could easily gain access to the underside of the roof, not withstanding the time to remove and then put everything back again.

I have since located this product, which gets good reviews, and have e-mailed them for more details - looks like you paint it onto the top side, and it reflects the heat, and dries a kind of grey colour.
http://www.solarx.co.uk/window-film-services/solar-reflective-paints-coating/

A lot of the products seemed to say they were not suitable for polycarbonate, but this one definitely says it is, just not quite sure on the coverage per litre, as they seem to recommend two coats, hence the email.

But looks like it could cost as little as £100, which would be a decent result - I'll have to spend the time painting it on of course, but I wouldn't have thought that would take more than half a day with a decent roller etc.

 

[catlad]

Sounds like a plan let us know how you get on.