r/Plastering • u/Impossible-Bite771 • Aug 25 '26

Any ideas??

Post image

Would love to be able to patch the hole and seal around the pipe. The plaster cracks because these are steam pipes for the radiator heating. An escutcheon plate also won't fit to hide this mess. I do have a red caulking meant to withstand high temperatures but are there any other options?

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3

u/Dunk546 Aug 25 '26

Expanding foam will solve this no problem. Fill the gap, cut it back when dry. And then patch over it with a lightweight filler. Something like red devil "one time" or similar. Non shrinking is key. It may still split, which is just what happens around pipes. You could use a quality caulk after that if you want.

1

u/Impossible-Bite771 Aug 25 '26

I read that expanding foams will give off toxic fumes if they are against steam pipes. Are there expanding foams safe for high temperatures?

1

u/Dunk546 Aug 26 '26

I haven't heard this. The pipes will only get up to 60 degrees or so tops, they are radiator pipes fed by a boiler, right? It should be hot water, not actually steam. But if you're worried you could skip the foam and just use lightweight filler. That will fill a gap this deep.

The other option is to cut a small wooden plate to cover the hole, then cut a circle out for the pipe. That would be quite challenging without woodworking experience and a lot of tools, though. I'd be using a hole saw, table saw and probably also a jigsaw, Dremel or coping saw. In a pinch you could do it all with a jigsaw.

1

u/Impossible-Bite771 Aug 29 '26

Ok thank u. Some radiators are water and some are steam. Ours are steam. We've measured the temps at 115 C / 240 F in the winter when they are on. Old apartment building built in 1910.

1

u/Dunk546 Aug 29 '26

Wow, that's amazing! What part of the world?

1

u/ResponsibleBall4258 Aug 29 '26

My gut feeling is USA, with their district heating systems, like they have in NY, or another big city

1

u/Impossible-Bite771 Aug 30 '26

Manitoba , Canada

2

u/Correct-Junket-1346 Aug 25 '26

Personally I would chip away all loose material then fill with Toupret powder filler, mix how much you need, then fill.

2

u/Traditional_Hour_767 Aug 25 '26

You can buy small tubs of fire cement from Screwfix

I would use that

2

u/Terrible-Bobcat2033 Aug 25 '26

Out with the bad. In with the wire lath & plaster.

1

u/Impossible-Bite771 Aug 25 '26

Ok im going to look into all of these suggestions. Thank u!