Slate roof ice dam

Does anybody here know if calcium chloride will damage slate? Just got our first call of the season for an ice dam and it's on a very large slate roof. Not sure what I can do for them at this point. Expecting the ice dam calls to pick up after this coming weekend storm. Not looking forward to that kind of work.

Snow guards, installed properly go a longgg ways in preventing dams.

Start them inside the wall, in staggered rows and never more than 6' between courses. The idea is to hold snow and ice in place, not attempt to catch it when it slides to the eaves. This has has little felt, and no I&W. No damming or leaks either.

This house has guards on eaves, dams, and leaks.

If you use heat cables, just drill a small hole in the bottom of the slate and slip a copper wire through the hole to attach to the clip for the cable. It works slick.

OS, it is the real thing. Not leaking into the house but through the soffit. Looks like it's happened in the past based on the condition of the wood. Last I talked to her I advised heat cables. They moved in last spring and she says that there are some wires up there that are plugged in but she didn't know what they were. I told her to try to find a switch to try to get them working. We'll see what happens. Thanks.

Is it real slate or the fake stuff? Real slate is just rock. The CC might leave some residue on it, but it will not hurt it. Is it leaking?

I have not really seen any damming yet, just an icicle here and there