Simple lean-to in alley

[Haylesurfer]

Hi All

Please see photos above
Am attempting to build simple alley way shelter
Although not intending anything to fancy just extra shelter for bikes, prams, surfboards etc do want it water tight with proper guttering
As can be seen old Cornish walls not the straightest
How best make it so water does not come down the walls? Planning on guttering, what best type of flashing? Or just a bit of render to fill between timber and walls?
Planning on using corrugated plastic sheets

Many thanks

[ndg]

You need to create a box gutter on one side:
https://en.wikipedia.org/wiki/Box_gutter


This should be flashed into the render (as should the high side of the roof) but with it being a sheltered location, and a shed, you may get away with not bothering.

There are a few calculators about to help you with sizing.

[Haylesurfer]

Thank you for your reply - really helpful
Sorry for sounding stupid - what are these gutter boxes made from ? Can you not just put square upvc guttering there or does the upvc sit into them
Many Thanks

[ndg]

You can't use a uPVC section as one wall of the gutter needs to be angled to match the roof pitch. So you form a box with plywood and then line it with something waterproof. Traditionally this would have been lead, which is very expensive! I'm planning on using something like this (example only):
http://www.roofingflashing.co.uk/lead-free-alterna...

[happychap]

Have you considered fixing the batons on either side at the same height and angle them away from the gate end and fix a gutter at that end. You would need to fix some batons going across to support your roofing sheets and run flashing down either side to prevent water getting in.