Lean-to roof and foundations

[richie4236]

I'm planning to build a lean-to in an awkward space at the side of my house. It's too small for a shed and at the moment is just acts as a giant litter tray for the neighbourhood cats. It's 6m from front to back and 2.7m wide at the front, narrowing to 1.3m at the rear of the property. Once done it will give me somewhere dry(ish) to park bikes, keep the wheelie-bin, recycling etc, and free up much needed space in my man cave (garage) for important stuff, like a beer fridge.

I plan to slab the floor, erect a wooden frame and close the top with a Multiwall Polycarbonate roof. I'm not sure about two aspects.

First, how much slope do I need to put on the roof? It will be adjacent to our single-story garage, so it's 230 cm from the floor to the soffit currently. I can drop the floor 5cm easily enough, to give a little extra head room, but if the roof needs to drop 10-20cm across the width it's going to be quite low on the open side by the time you factor in beams etc. What's a realistic minimum drop / angle for the roof to ensure it drains properly? I plan to put a gutter on the low/open side to collect rainwater.

Secondly, for the wooden uprights on the open side I was planning to dig down about 60cm and fill the holes with Postcrete. Is the best thing to bury the posts down to 60, cutting at the top to the right length, or could I use post fixings to bolt the upright posts to the concrete? I assume the former is better as this reduces the chances of the wind being able to lift the structure? Wanted to check the best approach here however.

Thanks for any help.

 

[theprinceofdarkness]

So is this like a long thin carport? The slope is mainly for the snow load, a couple of inches would do for rain. Look at other conservatories with a sloping roof, my one had a slope of about 15" in 10'. While washing the roof I noticed that the centre of the panels had dished by a couple of mm. So I would go for at least 4" with noggins on the wider bit to reduce the unsupported panel length to 4'*. There is a distinct problem with the wind getting under it and launching the roof like a kite. The posts, I am against burying wooden posts, they always rot at ground level, so mounting the posts into concreted in metal bits sounds good to me.
Frank
* the panels could flap against the noggins, stuffing a small piece of foam between the two, hopefully will sort it.