Roof age & life?

[bob-n]

I live in New England, where we get snow during the winter. I'm considering a grid-tie solar installation with panels flush to the roof, 30 degree angle (7/12), facing ESE, hoping for roughly 7kW peak. I'm just starting research and have a lot to learn. Please help me with some basic questions.
My roof is 12-year old asphalt architectural shingles. They appear to be in perfect condition, with no curling, no obvious missing aggregate, and no signs of nail-pops. To my hand, they feel a bit stiff, as if they've settled into place well and probably have started drying out. I feel that I could slide something under them, but not curl them upwards without breaking.
I understand that replacing a roof under solar will be a lot of extra labor. I've heard theories that solar panels will make a roof last longer by protecting it and also that solar panels can lead to premature mold growth on the roof, shortening its life.
With that as background:
Are these shingles too old to use as a base?
If I use these as is, is there anything in particular that I should consider for the installation related to this roofing?
If I replace these shingles, is there anything in particular that should be done during roofing installation or any consideration in selection of the new roofing as it relates to solar panels?
Local people recommend IronRidge's flush mounting system, so unless you recommend otherwise, I'm going to research that.
I haven't started planning, permits, economics or utility contacts yet. Lots to learn and do (and a few more dumb questions).
Thank you for your help.
Bob

[khanh dam]

I have cheap 3 tab shingles in the Carolinas that are 24 years old. Can probably make them last another several years if I go up there and tar some loose ones down and fix any popping nails.
Architectural shingles are 2x thicker and should EASILY last 25 years, some even have lifetime warranty.
the more space you have under panels the more air flow the better production. Flush mount systems are just for aesthetics.

[J.P.M.]

Your type of thinking is becoming more rare, that is you think before you act. Refreshing.

Every situation and roof is different. In less sunny, cooler but not brutally cold climates - think the pacific NW near the coast, mold growth in sheltered outdoor area is more likely than in, say, Santa Fe, NM which get cold in winter but the air is also as dry as a popcorn fart.

As for an array improving a roof's service life, that too probably depends on the application. Roofs in sunny, dry climates maybe/probably take more of a beating from sun than from moisture or frost heaving, but maybe not.

At 12 years and what may be a roof w/10-20 yrs. (?) of remaining service life, one or two considerations might be how long do you plan on staying there along with what you want to leave a buyer when you move. At this time, it appears a well designed and installed array can have a service life of at least 20 yrs., likely longer. So, will the roof outlast the array ? Tough call. Any remodeling in future plans that might involve roofing ? Might be a consideration to do it before PV. Just sayin'.

Chasing a leak under an array is a real PITA and worse than chasing one on an unarrayed roof, much less replacing a roof where an array is in place. I'd also be concerned about the array being reassembled and rewired safely, correctly and properly after removal.

I'm not a roofer, and no more than an amateur at it, so I'm ignorant of how long a roof will last, especially not having seen yours, but I am of the opinion that a roof is about the last place to play games or gamble with suitability and serviceability, or cheap out on quality.

If you do replace the shingles, consider doing it after you have a permitted design and have the roofer and solar installer coordinate the roof attachments. I did that and it worked out well, but part of the working out well part was because I was the project coord. and stayed on to of communication.

If by flush mounted you mean zero or little clearance between the roof deck and the underside of the array, for a lot of reasons, I'd respectfully suggest you consider not doing so. Solar devices operate at elevated temps. and having air circulating under them improves array efficiency, and the lower temps. will increase the probability of a longer service life of array components as well as enable you to simi-inspect under the array for debris, critters and damage.

Nothing wrong with Ironridge - just get 6+" of clearance between the roof and the bottom of the panels.

It'll also be easier to inspect and service depending on array layout. My under- but not entirely - uneducated guess is that the roof will last longer with about 6" or more space between the roof and the array. My clearance is ~ 11". Tight squeeze, but I can get under my array, but that was part of the design and done for other reasons besides lower array temps.

One last suggestion if you haven't done so already: Buy at bookstores or Amazon, or download (for free) a copy of "Solar Power Your Home for Dummies". A good primer.

Welcome to the neighborhood.