How to fix posts at 90º to horizontal when surface is sloping?

[nonsibicunctis]

Yesterday I erected the poles for an outdoor clothesline.

Each post has a flat base plate with four holes for securing to the base strata

I am fastening to a concrete path to which the clothes line will be parallel

The path is level along its width and length but slopes down from its high to low side, all along its length

I drilled appropriate holes for dynabolts & erected the posts and cross bar

Looked at my handiwork and all seemed good - the posts were vertical looking head on in relation to the length

However - me, very stupidly, had not accounted for the slope of the path from side to side

Accordingly, although I'd made sure the posts were at 90º to the concrete in each plane, they were now not vertical in the back to front plane but actually leaning forward.
...

After berating myself with a few curses, I put my tools away and took my dog for a walk.  I get depressed easily for it seems that whenever I attempt anything, I mess it up.  I have zero skills or experience as a tradesman but as a below-the-poverty line pensioner, have to do things myself because I can't afford trade rates.  No - I'm not seeking sympathy just explaining why I didin't do the obvious and have someone install the washing line for me.

...

This morning I have dismantled the clothes posts and drilled and cold chiselled the dynabolts out of the ground.

I had decided that I would cut back the concrete where the posts go so that it was level.  I tried an angle grinder with a concrete wheel but it was hopeless - i.e. I couldn't make it do the job.  So I tried a cold chisel but that seemed too laborious and just as difficult.

So, I'm back where I started but with some untidy looking holes where the original bolts were.

I need to re-erect the clothes line posts but ensure that I have them vertical to a 180 horizontal base, not the angle of the concrete path.

My ideas are:

• Use shims - however as the slope is even I'm not sure that this would work without more chiselling or something
• Use some concrete or similar to build rectangular rises on the path to a level height where the post bases will fit - but then how do I ensure that the concrete is even and at 180º on its surface? Should I make some sort of miniature form work or something - seems as though it would be very fiddly
• ?

If anyone can help with suggestions of a process that would , preferably, be relatively quick and simple and within the capacity of an imbecile, I would be very appreciative of your advice.

Thanks.Post base plateClose up of pathCurrent state rightPath along lenghtCurrent state left

[nonsibicunctis]

Thank you for your time, effort and interest.  I appreciate it.

[EricL]

Hi @nonsibicunctis

Please don't forget to post an update on your project, we look forward to seeing your clothesline post installed and ready for use.

If you have any other questions, please let us know.

Eric

[Stuckster]

This is the way. Simple and relatively inexpensive. How it's done on pretty much every industrial application. Could also use chemset instead of dropins but will be a bit more expensive.