I know there are a lot of roofing experts here and would appreciate your expert opinions.

My comp roof is 32 years old and showing signs of age. Last few years the roof has been losing sand and the shingles are fried crispy in this California sun. Time to take care of business, can't have a leaky roof.

I'm getting bids all over the map from $8900 for a basic 30 year composition overlay and then up to 22K for a complete strip 50 year roof adding a ridge vent.

Advice and insights would be much appreciated.

How many layers and how curly?

Not a big house. Single story, hipped roof, 33 squares.

You need advice from your local area. In northern climate strip and replace.

50 year comp is heavy stuff. A 30 or 40 year architectural is probably more like it.

What's it look like from your view in the attic?

32 years is rather aged.
Could have rotting plywood, insulation may have been wicking up multiple leaks for years.

As asked, how many layers?

Need more info.

Don’t do any type of overlay whatever you do have it cleaned off completely so that the sheathing may be accessed use synthetic underlayment and then whatever roofing system you’re comfortable with

I would never roof over that. Do your homework on roofing companies. Get old material torn off as someone above mentioned.

Do not overlay, strip and replace.

Is the "33 squares" calculation from your measurements or your contractor(s)?

Just curious, 33 squares will cover a 2550 sq ft home with a 4/12 pitch that has 12 inch eave overhangs. That's adding a 10% buffer which is common.

Does that sound about right?

If you want more than a random guess you're going to have to offer more details.

What others have said. Do not overlay. Strip off the old ones, use synthetic felt and 30 year Architectural shingle.
GreggH

i am not a roofer but i play one on the internet. i personally would not do a shingle over unless i was really stretched for cash and the roof was leaking. i would rip and replace with a 30 year unless i was 30 and had a lot of money. a properly installed 30 year shingle over a properly vented attic should last at least 30 years. thats here in PA where it gets hot and cold and rain and snow. i redid one on my camp a couple of years ago that my dad installed in the late 70's. it looked like hell but didn't leak and it was a 4/12 pitch.

and if you're curling a lot, i'd try to vent it better

I thought that if you laid shingles over shingles there was no warranty.......................

Shingles make a good base for putting down a metal roof. Personally I wouldn't put shingles on my dogs house.

+1