Ice damming –

The best explanation I have seen of why and how it occurs is
actually a video animation on Thermal Tech’s website

We have installed the Thermal Tech system as well as numerous Bylin
systems. The results are fantastic, look great, and ultimately are a more
cost effective system than the traditional “zig-zag” of heat tape on the

This year the mid-valley (Basalt, Carbondale, and Glenwood Springs)
suffered the perfect storm of conditions to create the largest ice dams we
have seen in years. In lieu of a full roof melt system the only option for
most building/home owners was to remove the snow from the highest risk areas
(i.e. north  facing, shaded,  valleys, and especially all  three)