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What is this radiator cover insulated with?
The other day, my electrician was helping me move a radiator cover so that we could access the wall behind it. He expressed a hypothesis that I did not like: this radiator cover, and all my other radiator covers, had a big fat slab of asbestos on top.
Is that really what is shown in the picture below? If so, should I do anything about it? If every other steam-heated house has had these in there for the past 80 years, the numbers suggest this is not a particularly imminent threat. If, on the other hand, this is unusual, I can't really say that for sure.