Solid polycarbonate sheeting for lean-to ?

[Sam Maguire]

Not mad about the appearance of multi-wall polycarbonate so looking at solid clear as a cheaper solution to glass. Lean-to will be added onto end of car port and will measure approx 3m x 3m with an 8 degree fall. It's just a covered area for bins and bikes etc and perhaps a veggie table. In the current climate the solid clear is obviously scarce but I think I have sourced 2 large sheets in 5mm which should do the trick. Timber support structure with rafters at 1m centres with glazing bars above. Finding it hard to get any decent install info online, has anyone used solid in a similar scenario ? I see other threads discussing the merit of opal over clear. Will the clear be high maintenance ? is 5mm a bit on the thin side ?

 

[Tigercubrider]

I would have thought that 5mm clear was a bit flimsy for a roof? Would the glazing bars fit something as thin as 5mm?

My conservatory has triple wall 15 or 18mm with rafters about 1m apart.
It's a bronze tint and imho looks a bit better than the clear but you still see dirt/ crap on it.
I am assuming this is the roof?

My mate's carport uses corrugated clear polythene and drains well, despite being a shallow slope.
He also has a covered area at the bottom of the garden behind a shed that's basically what you are talking about, again a timber frame and corrugated plastic.

Both predate his ownership of the house but we have replaced the car port roof once maybe 10 years ago

 

[Sam Maguire]

Thanks for reply. I have sourced nice looking grey glazing bars from OmegaBuild that can take any thickness.
The missus does'nt want either multiwall or corrugated which are both ideal for this job.
Glass is probably what I need but don't think budget will stretch hence the poly.
Just a little nervous and need to be put at ease !!

 

[Mw Roofline]

5mm poly will flap like anything. You’ll need 10mm solid poly but that’s more expensive than glass. Perhaps consider cut to size acrylic or Perspex, will be cheaper than poly.

 

[Best Glaze]

I wouldnt recommend using 5mm solid clear for a carport roof, even if the bars can take it it will flex like mad in the weather and eventually it will craze and become cloudy if it lasts that long. You will need Polycarbonate or Glass.

 

[Sam Maguire]

Thanks for the helpful replies. The support structure will be timber rafters at 1m centres.
Best Glaze, when you say I need polycarbonate I presume you mean multi-wall ?
Really want to go with flat and clear if possible like glass.
If I narrowed the rafter centres could I go with solid poly or perspex ? If so what thickness ?
Thanks again.

 

[Best Glaze]

I wouldnt recommend using 5mm solid clear for a carport roof, even if the bars can take it it will flex like mad in the weather and eventually it will craze and become cloudy if it lasts that long. You will need Polycarbonate or Glass.

There isn't really a cost effective way of doing your project without using 10mm perspex and as someone already pointed out that would be more expensive than using glass.
I guess if you wanted to narrow the rafters to maybe 500mm centers you could get away with 5mm.

 

[Sam Maguire]

Yes, I have re-jigged the design and plan to go with 5mm or 6mm solid with rafters at 550mm centres.
Thinking of using these type of fixings throughout instead of glazing bars - any thoughts ?
https://www.amazon.co.uk/Clear-Roofing-Caps-Corrugated-Screws/dp/B00GW0Y1ZC
Oversize the holes to allow for movement. Should I use gaskets or foam strips between poly and rafter ?
Any tips on drilling solid polycarbonate - type of drill bit etc ?

 

[Best Glaze]

If you can use glazing bars if your budget allows it. Get some spur point drill bits and dont have the drill spinning to fast!

 

[Sam Maguire]

Cheers. I will use glazing bars where there is a sheet to sheet joint but are those fixings ok for intermediate fixings on rafters where there is no joint. I see the button type are normally used for thicker multiwall sheets.