Waterway Company constructed a building at a cost of $2,508,000 and occupied it beginning in January 1998. It was estimated at that time that its life would be 40 years, with no salvage value.

a) In January 2018, a new roof was installed at a cost of $342,000, and it was estimated then that the building would have a useful life of 25 years from that date. The cost of the old roof was $182,400.

b) What amount of depreciation should have been charged annually from the years 1998 to 2017? (Assume straight-line depreciation.)

c) What entry should be made in 2018 to record the replacement of the roof? Prepare the entry in January 2018 to record the revision in the estimated life of the building, if necessary.