This dam will then force the additional water that comes off your roof during a thaw back up and under the shingles. Shingles are designed for water to go down and stay on top, not under the shingle. Once this water gets under your shingles, it will find its way down and into your house.
This water can cause all kinds of problems inside your home. Insulation can become soaked, drywall and ceilings can be damaged and mold could grow if the situation is not addressed. Some times the solution is very simple and inexpensive, other times when things get very wet, the damage can be very expensive to repair.
It is important to know that the interior damage is usually covered by your home owners insurance policy. If you notice signs of moisture or water entering the home, you should contact a professional who is familiar with roofing, ice dams, interior damage and home owners insurance policies and guidelines. The damage may be covered by insurance if it is extensive but only a trained professional can advise you of the extent of the damage and assist you through the claim process.