What is the shallowest angle allowed (in the UK) for a tiled pitched roof?

I am looking to build an exension to my house with a lean to type pitched roof using rosemary or dreadnaught flat tiles and would like to know what i can get away with.
What is the shallowest angle allowed (in the UK) for a tiled pitched roof?
1/4 per foot in the world, as gravity tends to remain constant all over.
Reply:assuming there's adequate support, so long as water runs off. As a matter of interest the angle of a thatch roof is as follows; line up a straw with the gable end of a house, spit on it, lower one end of the straw until the spit starts to run down the straw. Any angle less will not be enough. ie. if spit runs off so water will.
Reply:I do not know the code in England, but to function properly, the pitch for a tiled roof should not be less that 5:12. Less and wind blown water can cause a leak.
Reply:4-12 pttch but i wouldnt recomend nothing under 6-12 all depends on your climate.
Reply:40 degrees is the law but i managed 44 good luck this site should help you
Reply:I agree with Mel- 1/4" per foot is the standard for best runoff- works for roofs and plumbing.

lips