Loaded Question - Insight re: New Roofing

I am looking at putting a new roof on a house in Los Angeles. One story country style home with not a very high slope. What do you recommend between Certainteed, GAF and Owens Corning. We have a roof on top of a roof (they placed Calshake on top of the original wood shingles) so we need to take down two roofs and install plywood then the new roof. Major job. And insulate over the livingroom (pitched ceilings).

We also want to add insulation for part of the roof. I was told 3" minimum for insulation. Anything to consider with “green roofing”.

I read on another post that quality of Gaf isn’t so great (lots of loose pieces in the packaging). Want some texture but can’t afford top of the line. More middle of road.

What region are you in?,Location?

A roof on a roof reminded me a roof I did back in 08 were they put a 7/12 over a 4/12 to make it look more modern. When you looked down the vent holes you could see the roof system below.

I think your roof on a roof is in regards to two layers? New decking installed over the original decking is due to gaps?

My order of shingle choice would be this,

Certainteed
Owens Corning (2nd because of solid tar lines=leaks)
Tamko (Leak only warranty)
Malarky (Leak only warranty)
Altas (Leak only warranty)
IKO (Leak only warranty
GAF/ELK (GARBAGE)

GAF Timberline is the best laminate by far, and we have used them all. Certainteed is second best. Owens Corning is the worst due to problems with the seal strip trapping water. The others are in between.

A lot of installers and roofing pro’s felt ELK was the best laminate on the market. Unfortunetely GAF took care of ELK. Recall several posts by ELK installers who switched to the new GAF/ELK shingle and were very displeased with the quality. More recent feedback on the GAF/ELK shingles are thinner than ever.

I guess if your roofing a house in the middle of MN Winter go with Timberlines they cut like butter…

I drive through a lot of areas hit with 50-60mph wind and see a lot of blown of Timberline shingles. Of course the same is true of New Horizon but those at least are no longer made. High nails and overdriven nails may play a major roll with blow offs but rarely see Landmarks or Durations blowing off.

Certainteed has a ton of pattents through 3M a small local to MN based company.