With new tax law--how do I continue to claim the depreciation on my rental? Is it just new assets that are expensed--and basis of home, etc still depreciated the old way?

The TurboTax answers I've seen on depreciated are pre-Trump tax law.  I've depreciated the single-family home over 27.5 years, and some appliances over (I think) 7 years.  So I need to know how to handle that depreciation from before.  Also, I installed a new deck for $3500 in 2018--do I expense that (with the deminimus thing) or do I do the 27.5-year depreciation on the deck?  Thanks so much!  I've tried to do some homework on this, and still don't get it.