Stephen's Inbox

I would just not grow Ivy - its the devel to get rid of - and it can undermine the brick Mortar - some people think it makes the house look Pretty – but my opinion it devaluates it – but then every one to his own – this is my opinion and advice on ivy - keep away from it

Plus it would make pruning the rose more difficult...

Welcome to GoY, Stephen.
I think you will find that the ivy will not need the trellis to help it climbe the wall, it can cling to the wall using the tiny growths on its stems. Once it has established a root system in your soil it will soon start climbing!
However climbing roses will need some support. My preference is to use horizontal wires to support climbing and rambler roses, when their stems are growing horizontally they produce more flowers.
I would think twice before growing roses with ivy. Trees covered in ivy do not thrive, and it doesn't take ivy long to clothe a tree. A rose would succumb far more quickly .