A reader wrote in this question:
What is best to use to melt snow on different kinds of surfaces? We did some damage on our slate steps last year by using rock salt.
We polled some experts including Deren S. Monday and the consensus is that slate is definitely not the ideal choice to use in areas that need to be clear of snow. When designing for snowy climates the exterior selections should be salt-resistant to meet performance criteria.
If you’ve already got the slate installed here are the options as we see it.
1. Remove the slate and install a salt-resistant paver such as high-quality concrete that is also textured to be more slip-resistant.
2. Remove the slate and install thermal heat elements underneath and re-install the slate or install weather resistant material. Salt shouldn’t be needed if you go with this option.
3. Use a thermal heated walkway such as HeatTrak. These are temporary runners that go over your walkway and keep it clear from snow. This would be the easiest but also maybe the most unsightly option but it would keep a walkway clear when it snows and save your slate.
4. Forget the salt and focus on reducing the slip danger. Use sand or kitty litter. It won’t melt the ice but it will increase the coefficient of friction. Prolonged use of these products may scratch the slate, but then again, it is a walking surface.
There may not be a clear cut answer here but hopefully one of these options will work for you. Please feel free to offer other scenarios in the comments and if you’ve got a question of your own, send it over.