How to Prevent Icicles on the Roof When You Have Skylights

Seal the skylight. Purchase caulking strip--like thin, clay strips. Lay the strips inside the creases of the skylight, where the glass edges meet the ceiling. Feel for areas where cold air especially leaks in. Cover this area with two or three strips of caulking strip. Note that a water leak from ice and snow is caused by interior heat. Water from this melting gets trapped, creating an "ice dam" on the roof, causing severe interior water damage.

Check your home's insulation material. Determine the type, whether it is rolls and blankets, concrete, foam board, rigid foam or another material. Assess whether you need to add insulation by seeing if the insulation is thin or thinning around the skylight. Before adding any insulation material, if needed, ensure that your home is properly air sealed.

Weatherize your home. Create insulation improvements to your home. Develop proper ventilation to protect from moisture damage year-round and reduce ice in snowy weather.

Protect the eaves. Waterproof the eaves with a membrane, such as roofing felts, roll roofing, or metal sheets.

Lay the membrane along the lower edge of teh roof closest to the skylight. Note that peel-and-stick modified bitumen products are ideal and relatively simple to use. Purchase ones that come in 3-foot-wide rolls.

Waterproof the roof in spring or summer. If you have a shingled roof, remove the shingles surrounding the skylight opening. This allows for waterproofing measures. Purchase tar paper, also called roofing felt, in a roll. Lay in the tar paper in place of the shingles. Caulk the area where the tar paper touches the skylight edge. This prevents water and snow build up, so the water will rush off the sides of the house to the gutters instead of freezing by the skylight.