Shed roof v bird poo!

I have a simple garden shed with a pent roof, left by the previous owner when we bought the house 2 years ago.

The shed is near a shared wall, above which are high trees (my neighbours, but overhanging our garden).

My problem is this - birds sit or roost high above the shed roof, dump on it, and their guano is burning through the roof felt.

I don't know long it took to damage the old felt I've just replaced, but it didn't look old or seem particularly cheap/thin.

I've just replaced all the old felt with Marley Waterproofing Super Shed from Homebase; within a week the pigeons(?) have already started to leave their mark.

They're probably roosting way up in my neighbour's trees, and suggesting he or I pay for a tree surgeon seems like too much trouble. So my next thought is a more durable roofing.

Any thoughts? Would shingles be better at withstanding the attack, and could they be fixed straight on to the felt?

Or should I consider some sort of metal roof or similar?

No one got any ideas?

shed felt doesn't last long anyway. sunlight degrades it.

If it is a prestige, high-quality outbuilding with expensive equipment in it, you might justify the cost of a proper roof

Either place a proper slated roof on it but if its just the droppings your concerned about buy a plastic bird of prey to scare the pigeons away

Okay.

Can anyone recommend slate tiles (light?) that would be suitable for a shed roof? Could they be fitted directly on to the existing felt?

And what about a supplier?

http://geonel.net/tufftile.html

you can use the existing felt.