it had me worried a bit . however, watching them put it on kind of figured it out. Essentially they take off the shingles if needed then they put a water proof plastic layer wrap, then the traditional felt paper , but it is thicker and waterproof. then the shingle goes on . it is thinner than one would think, takes them about a week or so to do it as they fit it on . a bundle of their stuff weights about 20 pounds and shingle 75 pounds so the mass layer is different. Walking on the roof isn’t recommended, not because it damages the shingle, but there isn’t that slight give asphalt shingles has and one could slide off the roof in a hurry.
The company that did our roof… Bakeris Roofing , did an excellent job, plus inspected it twice before asking for the payment … They use metroshingle.
Now the business side of the shingle is a uv resistent polymer that the rock is fused to and that to the steel so it has the same outside materials. I would guess that if I had the ISS on the roof and aimed the antenna toward the roof, then with the different layers we might have signal reflection.
I do have the low -E double pane windows on the house and that does block signals to a point, but right now the signal strength is just fine.
The only thing that has me bugged a bit is that the utility company for the gas and electric is starting to install a transmitter to send to their towers meter readings. I wrote their company and inquired and found that they use 58 channels between 902 - 928 MHz.
Electric Meters - Every 30 seconds one set of transmissions is sent consisting of a standard consumption message 5.86 ms long followed in 250 ms by an interval data message message of 44.92 ms length.
Gas meter - Every 15 seconds an SCM message that is 5.86 ms long is sent. The VP2 transmits very 2.5 seconds. Taking that into account might be some conlict as the ranges overlap each other. The water meter is down in the 400 mhz range and I haven’t noticed anything . That thing is they drive through an area and wake up the transmitter with a signal and send it. It seems Midamerican energy wants the signal at anytime of the day, Some folks also have an interruptable power supply that the power companies can shut off power devices such as air conditioners when they think the power is peaking.
We don’t have the install yet,but I am betting within a year we will. I have noticed that we have had some power dips and blackouts with the heat rise and the UPS has helped out a lot.