What happens after 27.5 years with major improvements, can you still deduct?

[Joe Michaels]

Hi,

Just watched the latest BP podcast about cost segs and it got me thinking....What happens after depreciation runs out on your property?  So as I understand it, repairs/maintenance is fully deductible the same year but major improvements have to be depreciated.  What happens if you have an "improvement" after year 27.5.  

Say you need a new roof, or a new boiler at year 28 of ownership......does this turn into repairs/maintenance?  What happens?!

Thanks Guys!

Joe