Drainage for a patio can just be simply a gravel boarder at the end of the patio as seen below.
The gravel boarder can also disguise the height differences between the patio and your grass.
Your patio will always run away from the house because the last thing you want is water running towards your house.
Only in exceptional circumstances will we have to put a proper drainage channel in.
Charles William Paving & Landscapes
10 Union Place, Goole
Company Number 06696157
VAT Number 979 5046 67
Marshalls Member R01764