if it were me I'd do a risk assessment,If you're up a hill in the lake district then you'd need to be conservative, but in town in a sheltered spot then don't worry.
On the flip side, 1 degree is more than people might think at low pitches, if you look at the graph of tan (trigonometry) as you drop the pitch,eg if the rain can rise 10mm under the end of the tile that 1 degree can make a bigger difference.
Sorry I'm on my phone otherwise I'd try to explain better.
But all in all, it should be OK!
If you need to find a tradesperson to get your job done, please try our local search below,
or if you are doing it yourself you can find suppliers local to you.
Select the supplier or trade you require, enter your location to begin your search.
Please select a service and enter a location to continue...
Are you a trade or supplier? You can create your listing free at DIYnot Local