I have recently put Kahrs engineered wood down in our dining room. Ideally I would have taken the opportunity to chase the radiator pipes into the wall, but it didn't happen. I did manage to have each pipe going close to centrally through a 24mm hole.
The beech doughnuts that professional fitters used in other parts of the house don't look great and eventually get knocked off, so I am looking for an alternative. At first I thought I'd fill the space with a solid filler, but if the floor does move this might be a problem. On the one hand there's some give in the copper tube, on the other hand the compression fittings to the rad are a bit fragile and I don't want any leaks. On the third hand the pipes cycle through a wide temperature range and any solid filling is likely to crack.
So what are my choices. Brown silicone? plastic flangy things? Or am I stuck with hardwood doughnuts?
Leo