How far should wires be if nailed straight onto a brick wall?

Question

When training climbing roses onto a wall without the use of an arbor, how much space do you leave in between from wall to wires?

Answer 1

You only need enough space between the wires and the wall so you can thread the ties behind the wires.

It might be easier to use a wooden frame like these pictures, instead of wires. You only need to fix the frame to the wall at a few places, instead of fixing both ends of every wire.

https://www.davidaustinroses.co.uk/gallery/climbers-on-walls/

Answer 2

Usually, largeish eyelet or vine screws(https://www.amazon.co.uk/VINE-SCREW-ZINC-PLATED-75MM/dp/B0041OABD2 for instance) are used for this purpose; for a brick wall, it's usual to drill into the surface and use a rawl plug (not sure what they're called in USA) and screw the eyelets into those. Because the eyelet part of the screws naturally stick out from the wall surface, there's a gap between wall and wire of half an inch to an inch, depending on the size eyelet you use. For a Rose, half inch is fine, assuming you're not intending to thread the canes behind the wire, but, ensure the wire is strong, or heavy guage, before letting a rose grow up, or the weight of the rose canes over time will break it.