Can you re-roof over timberlines or architet shingles

Can we please have some examples of when not to re roof over one layer? can you re roof over arhitect shingles or timberlines ? isent it too bumpy ?

No it will be to wavy and there would not be a warranty.

ummm…timberlines are architectural. and no you shouldnt roof over them…way to bumpy and absolutley no warranty.

does make for a crappy lookin roof.