Supporting Acrylic ?

[RickH]

Need some ideas on how to achieve fitting an acrylic sheet.
I have a large ‘barn style’ outuilding, on 1 side it consists of 6 “ square post & gallow brackets.
The other side of this building is a fence, which comes up over 2.3 of the open bays.
The bays are open to allow through draught of air, and air come through fence no problem, the issue is the top 1/3rd allow rain to blow in, and because of the dwarf wall, it gets wet inside and stays wet long after rain has gone.

Hopefully this sketch will show what I mean:
http://tinyurl.com/28q5u7g

I don’t want to close off the bays as need air flow (& light) ... thought about putting in an acrylic sheet between the gallows brackets, just to prevent the blow in of rain.
If I sloped this so that the lower edge was clear of upright posts, it should also provide a ‘drip’ to prevent much of the water ingress.
i.e. as in sketch ..
http://tinyurl.com/24jt8r5
Space between each support posts is 6’ ... and there are multiple bays to do.
Assume I use something like 10mm thick Acrylic ... I can easily manufacture side & top edge supports out of wood .... some ½” x ½” either side of ends & top, would provide location slot.
The issue is what to use for bottom support ... i.e. along bottom edge.
6’ is a long span ... what I need is something I can bond to acrylic to provide a drip, and if it is longer than sheet would also provide a fixing point to outer face of posts.

I having been mulling over using aluminium 90 angle section, anybody any better ideas ?

 

[Burnerman]

I guess some aluminium 'L' bracket would be just fine, so long as you are using a fairly heavy section of the material.
Acrylic is hugely expensive and brittle....perhaps you could investigate polycarbonate instead? Its flexible, cheaper and doesn't shatter, and its easily drilled and tapped so you can use stainless screws or bolts. In fact another material that is used as bus shelter glass is possible - its called Vandalite I believe and I've seen it in building reclamation yards. I've no idea what it is chemically though!
John

 

[RickH]

The reason I had thought of Acrylic (Plexiglass) is due to good scratch resistance, Polycarbonate has good impact strength but is easily scratched.

I had not heard of 'Shelter glass' so will see what I can find about that.

 

[foxhole]

Needs no support at base, rain will drip off.If it's an out-building what does it matter if it scratches?

 

[RickH]

Not sure this would work .... if Polycarbonate twin or triple wall was used, I would assume over a 6' length it would flex too much in wind if no edge support ? .... also need to block end or it will fill up with spiders etc. (appreciate a pvc end cap could be used for that)

if no bottom rail, then what stops it sliding down ? .... unless you assume I am screw fixing sheet into side rails ?

 

[Burnerman]

I don't think triple wall stuff would be strong enough in this location - its dead easy to split if knocked.
John

 

[RickH]

My original thought was plain sheet ... but assumed I'd need to support across bottom edge .. 1) to stop it sliding out of position (unless I screw fix) 2) to help take weight if I fix ends of bottom'channel' to the upright posts.

Is 10mm a suitable thickness for this job ?

 

[Burnerman]

I would definitely support the bottom edge using angle material. You could drill through both the angle and plastic sheet and secure with stainless bolts. 6mm bolts would be fine.
10mm stuff is ideal - but as said before its very expensive and mighty heavy!
John

 

[RickH]

I had a link to triple 9 wall Makrolon ..
http://www.casupply.co.uk/acatalog/25mm_9-Wall_Polycarbonate.html

Not sure if that would suit ... certainly stronger than 16mm twin wall.

 

[Burnerman]

With care and a supported bottom edge with angle, this should be fine.
John

 

[foxhole]

Not sure this would work .... if Polycarbonate twin or triple wall was used, I would assume over a 6' length it would flex too much in wind if no edge support ? .... also need to block end or it will fill up with spiders etc. (appreciate a pvc end cap could be used for that)

if no bottom rail, then what stops it sliding down ? .... unless you assume I am screw fixing sheet into side rails ?

First time you have mentioned twin/triple wall your original post was solid 10mm.