Cable tie fixings for painted concrete outside?

can you not push in a long cable tie between a pair of concrete boards, loop round a post and then back through between an adjacent set of gravel boards and then form a loop?

If you stay away from the edges your chance of hitting rebar are quite small. I have drilled into both concrete posts and gravel boards without problems such as surface cracking. If you are just fixing to the gravel boards then I would drill a test hole, if that hits rebar drill elsewhere. Once you have established the position of one good hole you should be able to take a measurement for all the rest as the rebar position will most likely be the same for all the gravel boards.

Would the gap between two adjacent gravel boards hold the mounting part of a (stainless steel) P clip?

Then remove the paint with something. Any polyester/epoxy style glue is pretty good on concrete I even used car body fuller to reglue weights on a nylon washer drum. They worked until other reasons caused its scrappage

Id attack the surface with paint stripper and a wire brush, attach using CBF and then repaint

And in fact for reaosnable stresses hot glue is also possible

Have you tested it, using a metal detector?

I assume that you are fixing to the normal, slotted posts? If so, these may be overkill, but they are an option.

If you do go down this route just be aware they come in two sizes, 4"x

Covering several suggestions - gravel boards are pretty heavy and I need to be a couple of boards down so lifting (and keeping lifted) the boards could take a lot of strength and effort.

They were fitted over 10 years ago by a pair of muscular builders.

I had discounted using the gaps for this reason.

The rest of the fence run using wood makes fixing a doddle.

Cheers

Dave R

Drill in the crack between the boards, insert a nylon wall/raw plug and when it expands when screwing into it the weight of the gravel boards will hold it firmly in place.

What size cable? If small you can get pin plugs that will take the clips that use a nail for fixing.

Support for a Wisteria.

I would then look at a previous post that suggested the postfix fittings

Thanks. Those look to be the business. Have ordered some to try.

Cheers

Dave R