Ice dams are a major problem for roofs in cold climates, and slate roofs aren't immune to the issue. These dams form when snow or water collects on the roof. Heat escaping from inside the home melts the snow or ice so it makes its way beneath the slate shingles. It then refreezes and can lift up the slate or cause a shingle to break. It may also result in a leak indoors when the ice dam begins to melt. The following strategies help protect your roof.
Before blaming the roof for the ice dams, make sure your home is properly insulated. The biggest cause of ice dams is the heat that escapes from your home. Adding more insulation to your attic stops this heat loss. This greatly reduces, if not outright prevents, the formation of ice dams. You should always begin with adding new insulation no matter what kind of roofing material you have.
Flash the Eaves
Most ice dams form along the eaves on slate roofs. Adding some protection here prevents the water fro working underneath and refreezing. A common trick is to add a standard underlayment, like that used on asphalt roofs, beneath the slate tiles. Unfortunately, the underlayment doesn't have the longevity of the slate tiles, so it isn't the best option.
A better option is to use bib flashing made especially for slate roofs. The flashing is made of a flat sheet of metal, which is installed beneath the slates along the eaves. It serves the same purpose of stopping ice dams as underlayment, but it's longevity is at least equal to the slate tiles.
Switch Up the Design
Another option that works well on roofs with a minimal slope is removing the slate tiles along the eaves and replace these with a copper snow apron. Snow and water won't collect on the apron, so it slides right off without forming a dam.
If the snow apron won't fit your home's appearance, you can use a snow guard. These strips run along the roof and parallel to the eaves but a foot or so above them. Snows can't slide past the guard unless temperatures are high enough that it can't melt and refreeze.
Check the Gutters
Finally, just like any type of roof, you also want to make sure the gutters on a slate roof are clean and working properly as you enter the winter season. The quickest way to an ice dam problem is a clogged gutter.
If an ice dam damages your slate roof, contact a professional roofing contractor like Karbella Construction to start repairs.