Cracks in wall and fractured paint over CH pipes

[Sheepshanks]

Good afternoon all, I'm looking for some advice on how to deal with a recurring issue I have with a hallway wall.

As you can see in the attached images, the wall is cracking and the paint is crazing infront of where there are embedded central heating pipes. The pipes were wrapped in duct tape to protect them from the plaster however, no trunking was used. It looks particularly bad as I've attempted to rake out the cracks, fill with Toupret Fibacryl, use a fine surface filler over the top and finally sand it back. I think the fillers may have shrunk slightly, making the scars more visible.

Any advice on how best to deal with this? Should I have used Zinsser Peel Stop or Gardz at some point? My initial thoughts are to wait till Summer so the heating won't be on, sand the wall down removing the fractured paint, scrim tape over all the lines then fill over the top, feathering the filler out a few inches either side of tape so it blends in.

I appreciate any advice on this, many thanks.

 

[sparkwright]

It will always crack.
Bad idea to chase heating pipes into wall, as they will contract.
You could try removing all of the plaster, then use expanding foam all over, then scrim tape over the lot, then three coats of skim.
But there will always be the risk of cracking.
Far better to box in, or leave on show.

 

[Sheepshanks]

Thanks for your response, sparkwright. I had a gut feeling a potential fix would be more invasive than what I'd tried.

I think the main issue for me is the scarring that you can see in the attached images. I think this is because I've sanded the filler back flush and then the filler has shrunk over time leaving these scars. When they catch the light, they're quite visible. I'm thinking I should've applied more filler either side of the raked cracks and feathered into the wall rather than going completely flush.