Winter is here and snow is falling. I thought this would be a good time to write about Ice and Water Shield. Ice and Water Shield is an underlayment to fight against water penetration in your roof. It is extremely important to apply this to the most critical areas of your roof. Ice and Water Shield is a composite material of asphalt and polymers which is formed into a rolled sheet. The asphalt makes it vapor tight and the polymers make it sticky and elastic. This protective barrier is able to stretch and seal around nails driven through it. One of the most critical areas to be applied is from the heated edge or eaves. Ice dams usually form on the gutters and eaves of roofs and then freezing and melting take place causing water to be trapped under the shingles. Water attempts to penetrate the wood unless it is properly sealed. Other areas include around chimneys, skylights, valleys, and low sloped roofs that are 2 pitch or higher. If ice and water shield is applied correctly to these areas, you can be confident your roof will be worry free for years to come.