This is the tricky part on where do you place the system and how often do they need to be placed.
There are many things to consider when locating the system on the roof
1) How much snow is there in any given area
2) Are there lower roof and dormers to contend with
3) How is the wind going to effect the placement of snow on the roof
These few pictures show how the wind and higher roof lines will tend to increase snow loads and could cause problems if not designed with this in mind.
In some case people will want to add just a small line of snow guards above a door to protect people entering or leaving a building. See Below
These are just some of the factors that come into play, if you are unsure please call or e-mail us and we will clad help you in any way we can.