On 5/6/2016 1:03 PM, Cindy Hamilton wrote:
Thanks. That was interesting. I live in the snowy country where
flat roofs are not very popular, and solar loading is not extreme.

Yes. Here, even pitched roofs are very shallow. No "snow load"
to accommodate so the pitch is more a stylistic issue. (of course,
some roofing materials *require* pitch)

The vast majority of houses here are asphalt shingle, and I've
noticed a trend toward lighter colors.

The relentless sun cooks the asphalt shingles, here. And, any
load *on* them (e.g., walking!) damages them in short order
(they become very soft and easy to tear as your feet shuffle
across them).

Ceramic tile is, in theory, indestructible. But for the roof beneath!
And, as you can't easily INSPECT the roof beneath, you don't know
you have a problem until you see water stains on the ceiling.

With our roof, I have to be aware of outdoor temperatures/exposure
and how "pliable" the roof is likely to be. E.g., walking on it
on the coldest winter nights (which I often do to watch meteor
showers) leaves it prone to "cracking" -- lack of snow load
concerns means the roofs tend to be flimsy... it doesn't take much
structure to hold up a layer of PAINT!

Many homes have kit on the roofs (furnaces, heat pumps, air conditioner
compressors, swamp coolers, etc.) that need service from time to time.
So, you're vulnerable to the actions of any "maintenance personnel"
(who are more interested in fixing the kit than in worrying about
any wear and tear they are putting on your roof!)

The biggest risk, however, is from the glare that comes off the roof.
As the sun is always bright and the roof is painted white, you can
easily go "snow blind"! In one of my first efforts on the roof, I
came down to fetch something out of the garage. I had so quickly moved
from the bright light of sun-on-white into the RELATIVE darkness of
the garage that I was completely unprepared for the ensuing BLINDNESS!
"Cripes! I can't SEE!!!"

A few years ago we replaced
brown shingles with... mostly greyish-beige, I guess you could
call it. It's a very common color here.

Pitched roofs have to be concerned with appearances more than
flat -- you'd be hard pressed to tell what color our roof is
painted cuz it *is* flat (you'd need to be above it to get a view
of it).

If I could replace the roof entirely, I'd opt for a metal/tin roof
as it should require *no* maintenance (though might be LOUD
during the rainy season). Unfortunately, it requires more pitch than
we have available, here, so not an option.