Cold frame construction

[Greenleaves]

I am planning to build a 4mtr cold frame and wondered if anyone could advise on the three points below:

1. Is it best to divide the frame in to 4 x 1mtr sq bays?
2. Is there an optimum angle from back to front?
3. Auto vents or not?


Thanks

[roitelet]

Don't know about automatic vents but I have a 4 meter one and it is divided in two with independent lids. The slope was what looked right to me and the water runs off fine. Make it as deep as you can it is surprising how tall things are!

[bario1]

I seem to remember reading when building mine that 25 degrees was the optimum angle.

Mine's 2 metres long and split into two, and I find it very useful, as you can have one half open for hardy stuff, while tender stuff can still be snug in the other half. Having 4 compartments can only be a bonus!

Auto vents would be amazing, but they would limit the amount you could open the lights wouldn't they? How would you get stuff in and out? I have to prop my lights up almost vertical to get to the back of it, and in the height of summer I have things like aubergines growing in it that get quite tall. They seem to like the shelter it provides even with the lights propped fully open.