How to stop housemartins nesting below roof

For many years I've had this problem and this is the only solution that fully worked. Housemartins will come back annually to haunt and share their poo.. SO: Remove all trace of the nests with a hose. Fill any holes in the area (it's quite possible that over years they have penetrated under the eaves into the roof space. Fill it with a cement or silicon (do not use expandide). Then install a product called BirdBan or there are plenty similar products normally reserved for pigeons... They are cheap plastic spikes you can buy on ebay. Install them under the eaves where the inner spike is about an inch from the wall and you will never be bothered again. Finally I've seen a few posts from those who obviously like to wallow in bird poo year after year and whilst I do not advocate cruelty or breaking the law it may be best to wait til after autumn to do this. In the meantime you can think positive about these last poo and filth filled days as your last. :rotfl:

We tried numerous methods, despite the fact we love the birds the front of our house always had a dirty mark down the pebbledashing. The roof is quite high so hard to access to powerwash and we do not want the dashing painted. Our solution was to grow a Virginia Creeper (Boston Ivy) up the house. This is vigorous after the third year of planting, but unlike regular ivy clings on with with a type of sucker effect rather than damaging roots like regular ivy. It will cover the front of the house for the duration of spring and summer so the birds poop on the leaves which will turn crimson and then fall off to be composted in the Autumn. Therefore both bird poop and leaves are recycled and the dirty wall remains hidden. I will only have to keep the ivy trimmed out of the reach of the roof by a foot or so once or twice a year. As I stated, our roof is really high so for a regular house or bungalow this will be much more manageable.
Wisteria would also do, but needs some support.
Hope this idea helps someone