Roofing question...strip the old or roll right?

[Josh Turner]

What are the thoughts on shingling over a layer of existing shingles?  The roofers I have used always try to discourage me from doing it, but if your decking is all sound and the existing shingles are still laying pretty flat is there really any downside to it?  It would certainly save a tremendous amount of mess.

[Jeremy A.]

Originally posted by @Josh Turner:

Yep...so sort of mixed feelings on it as I expected.  Personally I'm not sure that I would ever do it on my own residence, but it doesn't seem like a bad solution for rental properties where every penny is being pinched as @Mark Fries suggested.  Thanks for the info.

 in maine we have added risk and weight of snow and ice. risky add more weight to aging roof. ive done both. but prefer rentals get metal roofs so no build up no replacement for 30-50 years. btw 1 inch ice equals 12 inch fresh snow.  Saturated snow weighs about 20 lbs./cubic foot. ... (S)1.25 = P, where (S) is the number of inches of snow on yourroof, and P is the pounds per square foot of that snow. adds up fast