I need more wall space in the boiler room and am thinking of putting up a sheet of form plywood on a brick wall outside of some water pipes:
The sheet I plan to put up is about 1000x1000 mm. And the distance to the wall needs to be +150mm:
Question: how do I secure (mount) the sheet onto the wall in a sturdy way? The sheet needs to be able to support around 10 kg of wall-mounted items. I would prefer not to have to place the sheet on the floor.
Threaded rod and nuts? Use the same rail that the pipes are mounted on.
+1 on that! Sometimes the answer is right in front of your nose.
IF for some reason you cannot/do not want to use that solution, the only clear option is to drill up, fill the drill hole with anchor compound, and insert a suitably long piece of threaded rod. Done correctly, it holds like a rock.
Don't make simpler solutions than that; just using a nylon plug, for example, can easily backfire. (Today, 10 kilos of load, sure, but tomorrow you'll discover how practical it was to hang all sorts of stuff there, and the day after tomorrow the kids will come and climb all over it, and then it gets messy.)