1. Ensure adequate insulation: Insulating the attic or roof space helps to maintain a uniform temperature across the roof, preventing snow from melting and refreezing at the roof's edges.

2. Ventilate the roof: Proper ventilation helps to remove excess heat and moisture from the attic, which reduces the likelihood of snow melting and refreezing at the roof's edges.

3. Seal air leaks: Seal any gaps or cracks in the attic floor or roof that allow warm air to leak into the attic.

4. Install a water-repellent membrane: Installing a water-repellent membrane under the roofing material can prevent water from penetrating the roof and causing damage.

5. Use a roof rake: Use a roof rake to remove snow from the roof to prevent ice dams from forming.

6. Install heat cables: Installing heat cables along the roof's edges can prevent ice from forming and help to melt any existing ice dams.