Help with Rendering please????

Hi I have just built some raised beds and was wondering if anyone can help with any advice for rendering them?
I intened to place 2 16mm batons 1m apart and screed of these in 1 coat, i belive i need the cement, sharp sand and feb slightly runnier than for laying blocks and mix 5-1. I will then leave til nearl set then float up?
Does this sound right as i have never rendered before but have done a bot of investigating?
The other thing is what is the waterproofer called i need to add to the mix?
Thanks for any help guys

What are you rendering on to - brick or block.

Waterproofer in the scratch coat is a 50/50 question some say always some say never.  "Feb" is the brand name - rather like hoover is for vacuum cleaner 

Your main problem here is going to be damp from the soil in the raised bed blowing the render off.  If you're one coating it rather than a thick scratch and a tight top coat. Id go with a 6:1:1 sand/cement/lime - level it off, let it go green and then rub it up.

I was talking to a plaster a while back who recommended 7:1 or even 12:1:1 personally I think that would end up on the floor.

Dont forget some capping, and a bellcast at the bottom and stainless angles unless you're confident to free hand them.

Thats what I think, but Im sure someone will be around in a bit to recommend something else.

Thanks for your help, i am rendering on to block.

Problem with Unibond (or other PVA) is, it isn't waterproof, and gets weak in moist conditions..

Rendering with sand/cement is often a problem as the moisture that finds its way under the render has problems getting out, so tends to blow the render off. Sand/lime could be a solution, but without top protection for the wall its still difficult (one reason why thatched buildings have big overhangs. Sand/lime is not so hard as sand/cement so is a bit more flexible. They used to use cow hair in the mix, nowadays mostly goat hair, but polypropylene fibres are available though I would have thought they were a bit smooth and so didn't anchor to the mix well. Most recommendations seem to use stainless mesh, but that seems a bit OTT.

There are loads of posts on the web for rendering walls eg http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=167
http://www.gardenersworld.com/how-to/projects/raised-bed/

Edit
PS lime needs to be builders lime, and maybe hydraulic. Not garden lime which might be just crushed chalk.

i would just not use the waterproofer, its not like your trying to keep water out of your beds. Works fine for me, and ive just done all my blockwork within the last couple of months!