It varies. Sometimes we do a complete strip & re-paint, other times we do a rub-down and respray and often its just a direct spray over.
With short leases it usually depends on the Lessee - they may have to pay for the paint job both ways (and if not, its factored into the lease price anyway) and often don't want to incur the cost of a complete strip down. Thats lots of manhours to pay for! Eventually you have to strip and repaint but its not undertaken lightly.
In the end you have to strip off paint when it gets too thick, if only to be able to do the structural inspections properly.
**************************
Through difficulties to the cinema