Plunge bed/cold frame

[glynnffc]

I need some idea for building the above. I have had several attempts at imitating the excellent arrangement seen at RBG in Edinburgh for alpines,particularly half hardy/hardy orchids, but my efforts always fall far short.
I would like the bed to be at waist height (It's easier on my back) but what do I make the floor from. Exterior ply doesn't last,but sheet steel seems excessive.
If any of you have any ideas or experience, or can recommend a good book with plans I would be very grateful.
Thanks in advance.
Glynn

[Tony Willis]

By coincidence I am just raising my frames of the floor,they are at present made of breeze blocks with the frames sat on top. This too low and also they stay wet  and I am using 60cm square flags as the base sat on breeze blocks. Mine are only one high but it is easy to make pillars two or three high. The frame is then sat on a wooden box on top of the flags,made from pressure treated timber. These are plunge frames filled with sand.

[Martinr]

Have a look at John Richards 'Northumberland Diary' on the AGS website, www.alpinegardensociety.net or to be more precise

http://www.alpinegardensociety.net/diaries/Northumberland/+August+/372/

and

http://www.alpinegardensociety.net/diaries/Northumberland/+September+/380/

[glynnffc]

Thanks for the quick replies.
I'd never thought of using a timber floor, but with the rest of the area being decked I should have some spares for the floor.
The links are very informative.
There seems to always be an answer out there,it's just knowing where to look.