This is called ice belt metal panels.
Patternfor ice dams on a metal roof.
It s possible the ice can get a grip on the raised metal screws commonly used to attach the metal sheets to the roof deck.
An ice belt a band of metal roofing installed at the eaves helps prevent the formation of ices dams by placing a low friction surface where ice dams are likely to form.
Ice dams can be frustrating.
An ice dam forms when the roof over the attic gets warm enough to melt the bottom layer of snow.
If an ice dam does form an ice belt will reduce the penetration of standing water.
Ice belt metal panels are typically short 3 4 and wide 2 5 3 and are made of thin gauge aluminum.
Why ice dams are dangerous.
In regards to the idea of a hot edge system on a metal roof it can be helpful.
On a metal roof there s almost nothing for an ice dam to adhere to.
So the ice dams still build just higher on the roof.
Metal roofs ward off ice dams pretty well to begin with but a steeply pitched metal roof is kryptonite to an ice dam.
The major issue with ice dams on the roof is that they trap the melting water running down from the top of the roof and thereby cause it the melted water to rise up underneath the roofing shingles and eventually seep through the boards and walls inside our homes.
A metal roof will generally shed snow better but snow running down the roof will still freeze on the unheated overhangs creating an ice dam.
The quality of installation is still the key and while a metal roof doesn t have the same weakness as composition shingles that can be lifted rising ice and water a metal roof that is not installed correctly can certainly leak with or without ice dams.
The snow melts into water and t.
Metal roofing can help but is not an ice dam panacea.
Heat tape installed at the eaves melts channels for the water to flow through.
The hot edge systems i am familiar with do not retrofit well onto an existing metal roof.